Cisco uBR7100 Series Universal Broadband Router Software Configuration Guide

Cisco uBR7100 Series Universal
Broadband Router Software Configuration
Guide
Cisco IOS Release 12.3 BC, 12.2 BC, 12.1 EC
November 2006
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Text Part Number: OL-2238-05
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Copyright © 2001–2006, Cisco Systems, Inc.
All rights reserved.
CONTENTS
Preface
vii
Purpose
vii
Cisco IOS Software Options
Audience
vii
viii
Organization
viii
Conventions
ix
Additional References
x
Obtaining Documentation xi
World Wide Web xi
Documentation CD-ROM xi
Ordering Documentation xi
Documentation Feedback xi
Obtaining Technical Assistance xii
Cisco.com xii
Technical Assistance Center xii
CHAPTER
1
Overview
1-1
Cisco IOS Releases and Images for the Cisco uBR7100 Series Router
12.2 BC Release Train and Images 1-1
12.1 EC Release Train and Images 1-2
Cisco uBR7100 Series Configuration Tools
1-3
Cisco IOS Software Operational Overview 1-4
Cisco IOS Software Location 1-4
Determining Your Cisco IOS Software Release
Upgrading to a New Software Release 1-5
Operating Standards for Cisco IOS Software
DOCSIS Cable Plants 1-5
EuroDOCSIS Cable Plants 1-11
2
Configuring the Cisco CMTS for the First Time
Preparing for Configuration
1-4
1-5
Cisco IOS Releases and Software Features 1-13
Software Features for the Cisco uBR7100 Series
CHAPTER
1-1
1-13
2-1
2-1
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Contents
Understanding Configuration Fundamentals 2-2
Using the Enable Secret and the Enable Password
2-3
Configuring the Cisco uBR7100 Series CMTS Using AutoInstall
2-7
Configuring Using the setup Facility 2-7
Configuring Global Parameters 2-8
Configuring Upstream Frequencies 2-12
Configuring Non-Cable Interfaces 2-13
Configuring Using the Configuration Mode
2-15
Using the Setup Facility for Cable Interfaces 2-17
Interface Slot Numbering 2-17
Configuring the Interfaces 2-17
Identifying the Cable Interface 2-19
Mapping Interfaces and Physical Ports 2-21
Identifying Port Adapter Slots 2-21
Configuring Global Parameters 2-23
Saving Your Configuration Settings 2-24
Checking Your Settings and Reviewing Your Configuration Changes
Where to Go Next
CHAPTER
3
2-24
2-25
Configuring the Cisco Cable Interface
3-1
Configuring the Downstream Cable Interface 3-1
Activating the Downstream Carrier 3-2
Setting the Integrated Upconverter 3-3
Setting the Downstream Channel ID 3-4
Setting the MPEG Framing Format 3-5
Setting the Downstream Modulation 3-6
Setting the Downstream Interleave Depth 3-6
Setting the Downstream Helper Address 3-7
Setting Downstream Rate Limiting 3-8
Configuring the Upstream Cable Interface 3-9
Setting the Upstream Frequency 3-10
Setting the Upstream Channel Width 3-11
Setting the Upstream Input Power Level 3-13
Activating Upstream Admission Control 3-14
Activating Upstream Forward Error Correction (FEC)
Specifying Upstream Minislot Size 3-15
Activating the Upstream Scrambler 3-16
Activating Upstream Differential Encoding 3-16
Activating Upstream Rate Limiting 3-17
3-14
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Activating Upstream Frequency Adjustment 3-18
Activating Upstream Power Adjustment 3-19
Activating Upstream Timing Adjustment 3-20
Activating the Upstream Ports 3-20
Setting Upstream Backoff Values 3-21
Enabling and Configuring Baseline Privacy 3-23
Introduction to the Baseline Privacy Interface (BPI)
Enabling BPI 3-26
Configuring Baseline Privacy 3-26
3-23
Configuring and Activating Frequency Agility 3-28
Creating Spectrum Groups 3-28
Configuring and Activating Spectrum Groups 3-29
Configuring Spectrum Group Characteristics 3-32
Activating Cable Address Resolution Protocol Requests 3-35
Activating Cable Address Resolution Protocol (ARP) Requests
Activating Host-to-Host Communication (Proxy ARP)
Activating Cable Proxy ARP Requests 3-36
3-35
3-36
Configuring DHCP Options 3-37
Activating Cable Relay Agent 3-37
Activating DHCP giaddr 3-37
Configuring Time-of-Day Service 3-38
Activating Time-of-Day Service 3-38
Setting Optional IP Parameters 3-38
Activating IP Multicast Echo 3-39
Activating IP Broadcast Echo 3-39
Activating Packet Intercept Capabilities
3-40
Configuring Cable Modulation Profiles 3-41
Configuring Cable Modulation Profiles 3-41
Configuring QoS Profiles 3-43
Setting QoS Permission 3-45
Enforcing a QoS Profile Assignment 3-45
Setting Quality of Service (QoS) for Higher Priority Traffic 3-46
Configuring a QoS Profile for Higher Priority Traffic 3-46
Monitoring and Maintaining QoS for Higher Priority Traffic 3-47
Setting and Viewing Concatenation 3-52
Setting Concatenation 3-52
Viewing Concatenation Status 3-53
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Contents
CHAPTER
4
Configuring Basic Broadband Internet Access
Overview of Basic Broadband Internet Access
4-1
4-1
Typical Routing Configuration For High Speed Internet Access
EuroDOCSIS Operation
4-6
Transparent Bridging Configuration
4-8
Integrated Routing and Bridging Configuration
Baseline Privacy Interface
CHAPTER
5
4-2
4-10
4-13
Troubleshooting the System
5-1
Using a Cable Modem at the Headend to Verify Downstream Signals
5-1
Managing Cable Modems on the HFC Network 5-2
Configuring Sync Message Interval 5-2
Activating Cable Modem Authentication 5-3
Activating Cable Modem Upstream Address Verification 5-3
Configuring Dynamic Contention Algorithms (Cable Insertion Interval, Range, and Data
Backoffs) 5-4
Configuring the Dynamic Map Advance Algorithm 5-5
Configuring Per Modem Filters 5-6
Configuring the Maximum Number of Hosts Attached to a Cable Modem 5-7
Configuring Cable Modem Registration Timeout 5-8
Clearing Cable Modem Reset 5-8
Clearing Cable Modem Counters 5-9
Configuring Traffic Shaping 5-9
Configuring Spectrum Management 5-11
Polling Cable Modems
5-15
Understanding Show Command Responses
General show Commands 5-17
5-17
Troubleshooting Cable Flap Lists 5-31
Displaying the Flap List 5-34
Troubleshooting with the Flap List 5-37
Setting Cable Flap List Aging 5-38
Setting Cable Flap List Insertion Time 5-39
Setting Cable Flap List Power Adjustment Threshold 5-39
Setting Cable Flap List Miss Threshold 5-40
Setting Cable Flap List Size 5-40
Clearing Cable Flap List 5-41
Customizing Other Flap List Values and Related Commands
Performing Amplitude Averaging
5-41
5-42
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Enabling or Disabling Power Adjustment
Setting Downstream Test Signals 5-44
Configuring Unmodulated Test Signals
Configuring PRBS Test Signals 5-45
Verifying Test Signal Output 5-45
Pinging Unresponsive Cable Modems
Pinging a Cable Modem 5-46
Verifying the Ping 5-46
Using the Cable Monitor Feature
5-43
5-45
5-46
5-46
Using Cable Interface debug Commands 5-48
debug cable arp Command 5-48
debug cable envm Command (Environmental Monitor Messages) 5-48
debug cable err Command (MAC Protocol Errors) 5-49
debug cable privacy Command (Baseline Privacy) 5-49
debug cable keyman Command (Baseline Privacy Activity) 5-49
debug cable mac-messages Command 5-49
debug cable map Command 5-49
debug cable modems Command 5-50
debug cable phy Command (Messages) 5-50
debug cable qos Command 5-50
debug cable range Command (Ranging Messages) 5-50
debug cable receive Command (Upstream Messages) 5-51
debug cable reg Command (Modem Registration Requests) 5-51
debug cable reset Command (Messages) 5-51
debug cable specmgmt Command (Spectrum Management) 5-51
debug cable startalloc Command (Channel Allocations) 5-52
debug cable transmit Command (CMTS Transmissions) 5-52
debug cable ucc Command (Upstream Channel Change Messages) 5-52
debug cable ucd Command (Upstream Channel Description Messages) 5-52
APPENDIX
A
Configuration Register Information for the Cisco uBR7100 Series Universal Broadband
Routers A-1
Configuration Bit Meanings
Bits 0–3 A-2
Bit 6 A-3
Bit 7 A-3
Bit 8 A-4
Bit 10 and Bit 14 A-4
Bit 11 and Bit 12 A-4
A-1
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Contents
Bit 13
Bit 15
A-5
A-5
Displaying the Configuration Register While Running Cisco IOS
A-5
Displaying the Configuration Register While Running ROM Monitor
Setting the Configuration Register While Running Cisco IOS
A-6
A-6
Setting the Configuration Register While Running ROM Monitor
A-7
INDEX
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Preface
This preface explains the objectives, software options, intended audience, and organization of the
Cisco uBR7100 Series Universal Broadband Router Software Configuration Guide.
Document Revision History
The Document Revision History table below records technical changes to this document.
Table 1 Document Revision History
Document
Revision
Date
Change Summary
OL-2238-04
October 9, 2005
Reformatted Chapter 1: “Overview of Cisco uBR7100
Series Software”. Added Document Revision History
table.
Purpose
This guide describes the basic configuration, maintainenance and troubleshooting for the
Cisco uBR7100 series universal broadband routers. This document describes the supported Cisco IOS
software feature sets as they exist in these Cisco IOS releases:
•
Note
Cisco IOS Release 12.1 EC (through release 12.1(13)EC4)
Unless otherwise indicated, the term Cisco uBR7100 series refers to all models of the Cisco uBR7100
series universal broadband router, including the Cisco uBR7111, Cisco uBR7111E, Cisco uBR7114, and
Cisco uBR7114E routers.
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Preface
Cisco IOS Software Options
Cisco IOS Software Options
The Cisco uBR7100 series supports Cisco IOS 12.1(7)EC, with the following software options:
Table 2
Software Options for Cisco uBR7100 Series
Product Number
‘Product Description
SU71M3K4-12107EC
Cisco uBR7100 Series IOS DOCSIS 2-WAY BPI
SU71M3K4-12107EC=
Cisco uBR7100 Series IOS DOCSIS 2-WAY BPI
SU71PK4-12107EC
Cisco uBR7100 Series IOS DOCSIS 2-WAY BPI IP+ (default)
SU71PK4-12107EC=
Cisco uBR7100 Series IOS DOCSIS 2-WAY BPI IP+
SU71PK4T2-12107EC
Cisco uBR7100 Series IOS DOCSIS 2-WAY BPI TELCO-RETURN IP+
SU71PK4T2-12107EC=
Cisco uBR7100 Series IOS DOCSIS 2-WAY BPI TELCO-RETURN IP+
CNR-EVAL
Cisco Network Registrar (CNR), 30-day evaluation kit
Audience
This guide is intended for system administrators and support engineers who configure and maintain the
Cisco uBR7100 series router. Many different delivery models exist for Cisco uBR7100 series
equipment:
•
In smaller networks, a single service provider manages all equipment and infrastructure.
•
In larger networks, multiple service operators (MSOs) and ISPs share responsibility for
provisioning and managing the cable plant and IP network.
How the MSO and ISP divide responsibilities depends on the service model. In some cases, the MSO
maintains and operates the cable plant and attached CMs and STBs, and the ISP owns, operates, and
maintains the regional network and IP infrastructure beyond the cable distribution hub. In other cases,
the CMTS and RF customer premises equipment (CPE) are viewed as part of the networking
infrastructure, and the ISP maintains control for provisioning and managing DOCSIS functionality.
Note
This guide considers the MSO and ISP as a single service principle with responsibility to provision and
manage DOCSIS-based cable modems and set-top boxes. The guide assumes administrators are familiar
with Cisco uBR7100 series hardware, DOCSIS or EuroDOCSIS requirements, and networking.
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Preface
Organization
Organization
This guide includes the following chapters:
Table 3
Document Organization
Title
Description
Chapter 1, “Overview of Cisco
uBR7100 Series Software”
Acquaints you with the Cisco uBR7100 series features and
Cisco IOS 12.1(7)EC software.
Chapter 2, “Configuring the Cisco
CMTS for the First Time”
Provides instructions to make basic configurations to the
Cisco uBR7100 series CMTS using AutoInstall, the Setup
Facility, or manual configuration mode. Includes sample
Cisco uBR7100 series software configurations.
Note
Complete the configurations in this chapter prior to
attempting additional configurations later in this guide.
Chapter 3, “Configuring the Cisco
Cable Interface”
Describes the command-line interface (CLI), and provides
instructions for multiple cable modem card configurations.
Chapter 4, “Configuring Basic
Broadband Internet Access”
Describes the parameters of configuring and maintaining basic
broadband Internet access.
Chapter 5, “Troubleshooting the
System”
Provides troubleshooting instructions for the configuration of
the Cisco uBR7100 series CMTS.
Appendix A, “Configuration
Register Information for the Cisco
uBR7100 Series Universal
Broadband Routers”
Provides information about the functions and configuration of
bits in the Cisco IOS Software Configuration Register.
Conventions
This guide uses the following conventions for command syntax descriptions and textual emphasis:
Table 4
Command Syntax and Emphasis Conventions
Convention
Description
boldface font
Commands and keywords are in boldface.
italic font
Arguments for which you supply values are in italics.
[ ]
Elements in square brackets are optional.
{x | y | z}
Alternative, mutually exclusive, keywords are grouped in braces and separated
by vertical bars.
[x | y | z]
Optional alternative keywords are grouped in brackets and separated by vertical
bars.
string
A nonquoted set of characters. Do not use quotation marks around the string or
the string will include the quotation marks.
screen
font
Terminal sessions and information the system displays are in screen font.
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Preface
Additional References
Table 4
Command Syntax and Emphasis Conventions (continued)
Convention
Description
boldface screen
Information you must enter is in boldface screen font.
font
italic screen font
Arguments for which you supply values are in italic screen font.
This pointer highlights an important line of text in an example.
Note
Timesaver
Caution
^
The symbol ^ represents the key labeled Control—for example, the key
combination ^D in a screen display means hold down the Control key while you
press the D key.
< >
Nonprinting characters, such as passwords, are in angle brackets in contexts
where italics are not available.
[ ]
Default responses to system prompts are in square brackets.
!, #
An exclamation point ( ! ) or a pound sign ( # ) at the beginning of a line of code
indicates a comment line.
Means reader take note. Notes contain helpful suggestions or references to materials not contained in
this publication.
Means the described action saves time. You can save time by performing the action described in the
paragraph.
Means reader be careful. In this situation, you might do something that could result in equipment
damage or loss of data.
Additional References
The following references provide additional information related to the Cisco uBR7100 Series router.
Related Documents
Related Topic
Document Title and Location
General Documentation
•
Cisco uBR7100 Series Technical Documentation Web Page:
http://www.cisco.com/en/US/docs/cable/cmts/ubr7100/configuration/guide/scg71pre.ht
ml
Cisco uBR7100 Series
Hardware Installation
•
Cisco uBR7100 Series Hardware Installation Guide:
http://www.cisco.com/en/US/docs/cable/cmts/ubr7100/installation/guide/hig7100.html
Cisco uBR7100 Series
Software Configuration and
Features
•
Cisco uBR7100 Series Release Notes
http://www.cisco.com/en/US/products/hw/cable/ps2211/prod_release_notes_list.html
• Cisco Cable Modem Termination System Feature Guide
http://www.cisco.com/en/US/docs/cable/cmts/feature/guide/cmtsfg.html
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Obtaining Documentation
Related Topic
Document Title and Location
Cisco IOS Command
Reference
•
Cisco Broadband Cable Command Reference Guide
http://www.cisco.com/en/US/docs/ios/cable/command/reference/cbl_book.html
• Cisco CMTS Error Messages
http://www.cisco.com/en/US/docs/cable/cmts/system/message/uberrchap1.html#wp105
3312
Additional Cable/Broadband
Information Resources
•
Cisco Cable/Broadband Technical Support Web page
http://www.cisco.com/pcgi-bin/Support/browse/index.pl?i=Technologies&f=893
• Cisco Multiservice Broadband Cable Guide
http://www.cisco.com/en/US/prod/collateral/video/ps8806/ps5684/ps2209/prod_brochur
e09186a008014eeb0.pdf
Obtaining Documentation
The following sections provide sources for obtaining documentation from Cisco Systems.
World Wide Web
You can access the most current Cisco documentation on the World Wide Web at the following sites:
•
http://www.cisco.com
•
http://www-china.cisco.com
•
http://www-europe.cisco.com
Documentation CD-ROM
Cisco documentation and additional literature are available in a CD-ROM package, which ships
with your product. The Documentation CD-ROM is updated monthly and may be more current than
printed documentation. The CD-ROM package is available as a single unit or as an annual subscription.
Ordering Documentation
Cisco documentation is available in the following ways:
•
Registered Cisco Direct Customers can order Cisco Product documentation from the Networking
Products MarketPlace:
http://www.cisco.com/en/US/partner/ordering/index.shtml
•
Registered Cisco.com users can order the Documentation CD-ROM through the online Subscription
Store:
http://www.cisco.com/go/subscription
•
Nonregistered Cisco.com users can order documentation through a local account representative by
calling Cisco corporate headquarters (California, USA) at 408 526-7208 or, in North America, by
calling 800 553-NETS(6387).
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Preface
Obtaining Technical Assistance
Documentation Feedback
If you are reading Cisco product documentation on the World Wide Web, you can submit technical
comments electronically. Click Feedback in the toolbar and select Documentation. After you complete
the form, click Submit to send it to Cisco.
You can e-mail your comments to [email protected].
To submit your comments by mail, use the response card behind the front cover of your document, or
write to the following address:
Attn Document Resource Connection
Cisco Systems, Inc.
170 West Tasman Drive
San Jose, CA 95134-9883
We appreciate your comments.
Obtaining Technical Assistance
Cisco provides Cisco.com as a starting point for all technical assistance. Customers and partners can
obtain documentation, troubleshooting tips, and sample configurations from online tools. For Cisco.com
registered users, additional troubleshooting tools are available from the TAC website.
Cisco.com
Cisco.com is the foundation of a suite of interactive, networked services that provides immediate, open
access to Cisco information and resources at anytime, from anywhere in the world. This highly
integrated Internet application is a powerful, easy-to-use tool for doing business with Cisco.
Cisco.com provides a broad range of features and services to help customers and partners streamline
business processes and improve productivity. Through Cisco.com, you can find information about Cisco
and our networking solutions, services, and programs. In addition, you can resolve technical issues with
online technical support, download and test software packages, and order Cisco learning materials and
merchandise. Valuable online skill assessment, training, and certification programs are also available.
Customers and partners can self-register on Cisco.com to obtain additional personalized information and
services. Registered users can order products, check on the status of an order, access technical support,
and view benefits specific to their relationships with Cisco.
To access Cisco.com, go to the following website:
http://www.cisco.com
Technical Assistance Center
The Cisco TAC website is available to all customers who need technical assistance with a Cisco product
or technology that is under warranty or covered by a maintenance contract.
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Preface
Obtaining Technical Assistance
Contacting TAC by Using the Cisco TAC Website
If you have a priority level 3 (P3) or priority level 4 (P4) problem, contact TAC by going to the TAC
website:
http://www.cisco.com/tac
P3 and P4 level problems are defined as follows:
•
P3—Your network performance is degraded. Network functionality is noticeably impaired, but most
business operations continue.
•
P4—You need information or assistance on Cisco product capabilities, product installation, or basic
product configuration.
In each of the above cases, use the Cisco TAC website to quickly find answers to your questions.
To register for Cisco.com, go to the following website:
https://tools.cisco.com/RPF/register/register.do
If you cannot resolve your technical issue by using the TAC online resources, Cisco.com registered users
can open a case online by using the TAC Case Open tool at the following website:
http://tools.cisco.com/ServiceRequestTool/create/launch.do
Contacting TAC by Telephone
If you have a priority level 1 (P1) or priority level 2 (P2) problem, contact TAC by telephone and
immediately open a case. To obtain a directory of toll-free numbers for your country, go to the following
website:
http://www.cisco.com/en/US/support/tsd_cisco_worldwide_contacts.html
P1 and P2 level problems are defined as follows:
•
P1—Your production network is down, causing a critical impact to business operations if service is
not restored quickly. No workaround is available.
•
P2—Your production network is severely degraded, affecting significant aspects of your business
operations. No workaround is available.
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Obtaining Technical Assistance
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C H A P T E R
1
Overview of Cisco uBR7100 Series Software
The Cisco uBR7100 series uses Cisco IOS® software to offer enhanced stability, features, performance
and investment protection. This chapter summarizes system and software features of the Cisco uBR7200
series Cable Modem Termination System (CMTS). This chapter contains the following sections:
Section
Purpose
Cisco IOS Releases and Images for the Describes the supported Cisco IOS release trains, associated
features, and latest Cisco IOS images for each recently
Cisco uBR7100 Series, page 1-2
supported train.
One early step in CMTS feature configuration is to verify
your Cisco IOS release train, the associated image and
feature set. This section guides you in determining such
information.
“Cisco uBR7100 Series Router
Configuration Tools,” page 5
Provides an overview of the configuration tools available
when choosing your configuration method.
“Supported Software Features for the
Cisco uBR7100 Series,” page 6
Describes the features and configuration utilities that are
available on the Cisco uBR7100 series.
“DOCSIS and CMTS Interoperability,” Provides an overview of DOCSIS NTSC and EuroDOCSIS
cable plants, DOCSIS-compliant signals, and traffic
page 25
engineering.
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1-1
Chapter 1
Overview of Cisco uBR7100 Series Software
Cisco IOS Releases and Images for the Cisco uBR7100 Series
Cisco IOS Releases and Images for the Cisco uBR7100 Series
The Cisco uBR7100 series router runs the IOS image that is located on the Type II Personal Computer
Memory Card International Association (PCMCIA) Flash memory disks. These disks are located in the
two PCMCIA slots in the primary Performance Routing Engine 1 (PRE1). A PCMCIA disk in either slot
can store a Cisco IOS image or configuration file.
In addition to the Flash memory disks, each PRE1 module contains onboard Flash memory that is used
to store a boot loader. The loader executes following a system reset to reload and execute the Cisco IOS
software on the Flash memory disks.
The PRE1 module also stores the system configuration in the onboard Flash memory. The configuration
information read from the Flash memory is buffered in operational memory following initialization, and
is written to the Flash memory device when you save the configuration.
Each line card also contains onboard Flash memory that is used to store a boot loader, similar in function to
that used on the PRE1 module. However, the line card loader executes following a system reset, line card
reset, or line card insertion to reload and execute any code that must run on the line card for it to operate
properly. Software images may also be stored on an external TFTP server. If the Cisco uBR7100 series router
is so configured, it then downloads the proper image from the TFTP server and executes it.
This section describes the supported releases, latest images, memory requirements, and major software
features for the following Cisco IOS software:
•
Cisco IOS Software Location
•
Determining Your Cisco IOS Software Release
•
Upgrading to a New Software Release
•
12.2 BC Release Train and Images
•
12.1 EC Release Train and Images
Cisco IOS Software Location
Cisco IOS software is stored on the PRE1 module, which includes two PCMCIA slots that are accessible
from the front panel. Either slot can store an IOS image or configuration file.
The Flash memory on the PRE1 module is used to store a simple ROM monitor or boot loader. The loader
executes following a system reset, line card reset, or line card insertion.
Line card images may also be stored in PRE1 module Flash memory or on an external TFTP server.
The PRE1 module stores the system configuration in a 512 KB NVRAM device. Configuration
information read from NVRAM is buffered in RAM following initialization and is written to the device
when you save the configuration.
Determining Your Cisco IOS Software Release
To determine the version of Cisco IOS software running on the Cisco uBR7100 series router, log in to
the router and enter the show version command in privileged EXEC mode. For example:
Router> show version
Cisco Internetwork Operating System Software
IOS (tm) 12.2 XF Software (ubr10k-k8p6-mz), Version 12.2 XF, RELEASE SOFTWARE
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Overview of Cisco uBR7100 Series Software
Cisco IOS Releases and Images for the Cisco uBR7100 Series
Upgrading to a New Software Release
An upgrade is an order placed for a Cisco IOS® feature set that contains more functionality than the one
that you are replacing. And upgrade is not an update. An update consists of installing a more recent
version of the SAME feature set. Exception— If a feature set has been made obsolete, the next, closest
feature set, on a more recent release, will be considered an update.
For general information about upgrading to a new software release, refer to the Cisco IOS Upgrade Ordering
Instructions on Cisco.com.
12.2 BC Release Train and Images
The 12.2 BC train is an interim release train that provides DOCSIS 1.1 two-way support, along with
support for selected new features.
Cisco IOS Release 12.2(4)BC1b, provides a migration path from the earlier 12.2 XF releases. Cisco IOS
Release 12.2(4)BC1b supports the Cisco uBR7100 universal broadband router, which provides a
high-capacity, high-throughput cable modem termination system (CMTS), optimized for aggregating traffic
at the edge of the cable network. Designed for cable operators and service providers, the platform connects
residential subscribers via cable modems, digital set-top boxes, or IP telephony cable modems for high-speed
data, broadband entertainment, and IP telephony solutions.
Note
Cisco IOS Release 12.2(4)BC1b does not include support for telco-return images.
Cisco IOS 12.2(15)BC2b Images and Requirements
Table 1-1 displays the memory recommendations of the Cisco IOS feature sets for the Cisco uBR7100
universal broadband router for Cisco IOS Release 12.2(4)BC1b. Cisco uBR7100 universal broadband
routers are available with a 48-MB or 120-MB Type II PCMCIA Flash memory card.
Table 1-1
Memory Recommendations for the Cisco uBR7100 Series Routers, Cisco IOS Release 12.2(15)BC2b Feature Sets
Software Image
Recommended
Flash Memory
Recommended
DRAM Memory
Runs From
DOCSIS Two-Way
ubr7100-p-mz
16 MB Flash
128 MB DRAM
RAM
DOCSIS Two-Way IP Plus
ubr7100-is-mz
16 MB Flash
128 MB DRAM
RAM
DOCSIS Two-Way with BPI
ubr7100-k8p-mz
16 MB Flash
128 MB DRAM
RAM
DOCSIS Two-Way IP Plus with BPI
ubr7100-ik8s-mz
16 MB Flash
128 MB DRAM
RAM
ubr7100-boot-mz
None
None
—
Feature Set
Two-Way Data/VoIP Images
Boot Image
UBR7100 Boot Image
The image subset legend for Table 5 is as follows:
•
i = IP routing, MPLS-VPN support, and noncable interface bridging, including Network Address
Translation (NAT)
•
k8 = DOCSIS Baseline Privacy and MPLS-VPN support
•
p = IP routing with Intermediate System-to-Intermediate System (IS-IS) and Border Gateway
Protocol (BGP); MPLS-VPN support; no NAT
•
s = "Plus" features: NAT and Inter-Switch Link (ISL)
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Overview of Cisco uBR7100 Series Software
Cisco IOS Releases and Images for the Cisco uBR7100 Series
Note
All images support all of the hardware listed in the Cisco uBR7100 Series Release Notes available on
Cisco.com, unless otherwise indicated:
http://www.cisco.com/en/US/docs/cable/cmts/ubr7100/release/notes/12_3bc/123BCu71.html
12.1 EC Release Train and Images
Release 12.1 EC is an early deployment (ED) release based on Release 12.1 E, which serves as the train's
starting point. Release 12.1 E, in turn, is based on Release 12.1 Mainline. Early deployment releases
contain fixes to software caveats as well as support for new Cisco hardware and software features.
Feature support is cumulative from release to release, unless otherwise noted.
Cisco IOS 12.1 EC Images and Requirements
Table 1-2 displays the memory recommendations of the Cisco IOS feature sets for the Cisco uBR7100
universal broadband router for Cisco IOS Release 12.2(11)CY. Cisco uBR7100 universal broadband
routers are available with a 48-MB or 120-MB Type II PCMCIA Flash memory card.
Table 1-2 displays the memory recommendations of the Cisco IOS feature sets for the Cisco uBR7100
series universal broadband routers for Cisco IOS Release 12.1(20)EC2. Cisco uBR7100 series universal
broadband routers are available with a 16-MB or 20-MB Type II PCMCIA Flash memory card.
Table 1-2
Memory Recommendations for the Cisco uBR7100 Series Routers, Cisco IOS Release 12.1(20)EC2 Feature Sets
Software Image
Recommended
Flash Memory
Recommended
DRAM
Memory
Runs From
DOCSIS Two-Way with BPI
ubr7100-k1p-mz
16 MB Flash
128 MB DRAM
RAM
DOCSIS Two-Way IP Plus with BPI
ubr7100-ik1s-mz
16 MB Flash
128 MB DRAM
RAM
DOCSIS Telco-Return IP Plus with BPI
ubr7100-ik1st-mz
16 MB Flash
128 MB DRAM
RAM
ubr7100-boot-mz
None
None
—
Feature Set
Two-Way Data/VoIP Images
Boot Image
UBR7100 Boot Image
The image subset legend for Table 3 is as follows:
Note
•
i = IP routing, MPLS-VPN support, and noncable interface bridging, including Network Address
Translation (NAT)
•
k1 = DOCSIS Baseline Privacy and MPLS-VPN support
•
p = IP routing with Intermediate System-to-Intermediate System (IS-IS) and Border Gateway
Protocol (BGP); MPLS-VPN support; no NAT
•
s = "Plus" features: NAT and Inter-Switch Link (ISL)
•
t = Telco-Return
All images support all of the hardware listed in the Cisco uBR7100 Series Release Notes available on
Cisco.com, unless otherwise indicated:
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Cisco uBR7100 Series Router Configuration Tools
http://www.cisco.com/en/US/products/hw/cable/ps2211/prod_release_notes_list.html
Cisco uBR7100 Series Router Configuration Tools
Cisco Network Registrar (CNR)
Cisco provides the Cisco Network Registrar (CNR) with each Cisco uBR7100 series router. CNR
dramatically improves the reliability of naming and addressing services for enterprise and service
provider networks. CNR provides scalable DNS and DHCP services and forms the basis of a DOCSIS
cable modem provisioning system.
CNR is a configuration tool that automates dynamic IP address allocation to cable interfaces, PCs, and
other devices on the broadband network. CNR allows you to track serial numbers and MAC addresses
for each cable interface on your network, and reduces customer service involvement when tracking
subscriber CPE equipment.
For additional information about using CNR, refer to the latest CNR documentation at Cisco.com.
DOCSIS CPE Configurator
Cisco also offers an HTML-based DOCSIS CPE Configurator tool that can be accessed from Cisco.com.
The tool is designed to collect information needed to generate a DOCSIS CM configuration file. The
generated file is in binary format consistent with the DOCSIS RF Specification (SP-RFI-105-991105).
Cable Modem Configuration File Editor
The Cisco uBR7100 series routers support the cable config-file command, which provide for the online
creation of DOCSIS configuration files, which can then be stored on the router’s Flash memory or copied
to a TFTP server. The CLI commands to create these configuration files can be part of the Cisco IOS
configuration file that the router loads on power-up so that they are immediately available to cable
modems on the network.
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Supported Software Features for the Cisco uBR7100 Series
Supported Software Features for the Cisco uBR7100 Series
This section summarizes Cisco uBR7100 series router software features for all supported Cisco IOS
Release trains, and directs you to additional configuration information for each feature.
Cisco uBR7100 Series Features and Cisco IOS Releases
Table 1-3 summarizes the software-related features and related Cisco IOS releases that support the
Cisco uBR7100 series router. Cisco IOS features indicate the first release in which the feature was
introduced. Unless otherwise noted, feature support continues in later releases of the same or related
Cisco IOS release train.
Features are organized in the following categories:
•
Cisco Command-Line Enhancements, page 1-7
•
Cisco Quality of Service Features, page 1-7
•
DHCP Servers and Feature Support, page 1-9
•
DOCSIS Feature Support, page 1-10
•
High Availability Features, page 1-15
•
Intercept Features, page 1-15
•
IP Networking, page 1-16
•
IP Routing, page 1-16
•
Management Features, page 1-18
•
PacketCable and Voice Support Features, page 1-20
•
Security Features, page 1-20
•
SNMP Features and Enhancements, page 1-22
•
Spectrum Management Features, page 1-23
•
Testing, Troubleshooting and Diagnostic Features, page 1-23
•
VLAN Features, page 1-23
•
VPN Features, page 1-24
•
WAN Optimization and Service Features, page 1-24
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Supported Software Features for the Cisco uBR7100 Series
Table 1-3
Cisco uBR7100 Series Feature List with First Supporting Release Train
First Cisco IOS
Release
Feature
Description
Cisco Command-Line Enhancements
Configurable
registration timeout
12.1 EC
Statistical values
12.1 EC
added to show
controller int cx/y
upstream command
Changes the CM registration value (the T9 timer); the cable registration-timeout
minutes command sets the T9 timer to the new value (from 2 to 60 minutes). The no
cable registration-timeout command resets the T9 timer to its default of 3 minutes.
Displays the following additional statistical counters in the output of the show
controller cx/0 upstream number command:
•
Average percent of upstream utilization in minislots
•
Average percent of contention slots
•
Average percent of initial ranging slots
•
Average percent of minislots that were due because the MAP scheduler was not
able to request them in time
WCCP and
WCCPv2
12.1 EC
Identifies the web caching protocols supported.
Show Controllers
Cable Enhancement
12.2 BC
The Show Controllers Cables Extensions feature has been supported for Cisco IOS
Release 12.2(15)BC2b.
In this feature, the mem-stats, memory, proc-cpu, and tech-support keywords execute
the related command on the processor that runs on are added to obtain the relevant
information from the onboard processor on Broadband Processing Engine (BPE) cable
interface line cards, such as the Cisco uBR-MC16U/X, Cisco uBR-MC28U/X, and
Cisco uBR-MC5X20S/U cards. This allows the user to obtain information that is
specific for that particular cable interface card, as opposed to having to run these
commands on the entire router.
Refer to Cisco uBR7100 Series - Cisco IOS Release 12.2 BC:
•
http://www.cisco.com/en/US/docs/ios/12_2/12_2b/12_2bc/release/notes/u7108bc1.
html
Cisco Quality of Service Features
Cisco express
forwarding (CEF)
12.1 EC
Supports Cisco’s processing switching protocol to enable traffic decisions to be made
quickly.
Committed access
rate (CAR)
12.1 EC
Provides the means to allocate and limit bandwidth to traffic sources and destinations,
and specify policies to handle traffic exceeding the bandwidth allocation. CAR
policies can be utilized at the ingress or egress of the network. The feature uses token
bucket filters to measure traffic load and limit sources to bandwidth allocations.
DOCSIS 1.0 QoS
extensions
12.1 EC
Allows the Cisco uBR7100 series to specify priority service flows higher than those
specified in DOCSIS 1.0.
Downstream rate
shaping
12.1 EC
Supports buffering downstream grants to rate-exceeding cable interfaces, without
incurring TCP-related timeouts and retransmits.
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Supported Software Features for the Cisco uBR7100 Series
Table 1-3
Cisco uBR7100 Series Feature List with First Supporting Release Train (continued)
First Cisco IOS
Release
Description
Feature
Downstream rate
shaping with ToS
12.1 EC
Enables to be partitioned into multiple classes of service. Uses the three precedence
bits in the ToS field in the IP header to specify class of service assignment for each
packet.
Those packets with the IP precedence bit set in the IP packet are given higher priority.
This allows the CMTS administrator to calculate the data rate for a given flow, in
addition to the data rate configured on a per cable modem basis.
Multi-SID support
12.1 EC
Allows the Cisco uBR7100 series to support the definition of multiple SIDs on the
upstream. This includes multiple service classes per cable interface, enabling
administrators to delegate higher priority as required.
QoS profile
enforcement
12.1 EC
Allows the Cisco uBR7100 series to override the provisioned service class of a
cable interface at the time of registration with a CMTS-defined QoS profile.
Resource
Reservation
Protocol (RSVP)
12.1 EC
Works in conjunction with WFQ; helps the router establish a weight for different types
of packets that affect the order in which the packets enter the output queue and are
placed on the cable network for transmission; that is, higher priority packets are routed
through the interface with a QoS method that allows the packets to receive priority
over standard data frames. A router that supports RSVP gives priority to packets that
fall into a reservation within RSVP.
TAG/NetFlow
switching
12.1 EC
Provides high performance for network layer services, enabling per-flow application
of network services such as security and traffic accounting. Data collected for each
flow includes:
•
Source and destination IP address
•
Start of flow and end of flow timestamps
•
Packet and byte counts
•
Next hop router address
•
Input and output physical port interfaces
•
Source and Destination TCP/UDP port numbers
•
IP protocol type
•
Type of service (ToS) field
•
TCP flags
•
Source and destination autonomous system numbers
•
Source and destination subnet masks
Upstream rate
(traffic) shaping
12.1 EC
Supports buffering upstream grants from rate-exceeding cable interfaces, without
incurring Transmission Control Protocol (TCP)-related timeouts and retransmits.
Weighted fair drop
(WFD)
enhancements
12.1 EC
In addition to other traffic shaping techniques, a new configuration field associates a
maximum bandwidth in kbps with a particular setting of IP type of service (ToS) bits.
This can be used to ensure that certain traffic, such as data, does not exceed a preset
rate limit and thereby interfere with higher priority real time traffic.
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Table 1-3
Cisco uBR7100 Series Feature List with First Supporting Release Train (continued)
Feature
First Cisco IOS
Release
Description
Weighted fair
queuing (WFQ)
12.1 EC
Performs priority output queuing and custom queuing to grant resources to important
sessions when network bandwidth is saturated; typically used for digitized higher
priority real time packets to help reduce delay. WFQ provides expeditious handling for
high priority traffic, requiring low delay, while fairly sharing the remaining bandwidth
between lower priority traffic. WFQ divides link traffic into high and low priority
flows based on metrics including IP precedence and traffic volume.
Weighted random
early detection
(WRED)
12.1 EC
Provides the ability to specify traffic handling policies to maximize throughput under
congestion conditions. RED works in conjunction with TCP to intelligently avoid
network congestion. WRED combines IP precedence and RED capabilities to provide
differentiated performance characteristics for different classes of service, thus
providing preferential traffic handling for higher priority traffic. Administrators can
define minimum and maximum queue depth thresholds and drop probabilities for each
class of service.
DHCP Servers and Feature Support
DHCP cable modem 12.1 EC
host ID
(also known as cable
modem and host
subnet addressing)
(also known as cable modem and host subnet addressing)Allows the Cisco uBR7100
series to modify the giaddr field of DHCPDISCOVER packets, based on whether the
source is a cable interface or a host. This helps automate provisioning.
Integrated DHCP
server
12.1 EC
Simplifies provisioning, offering an integrated Dynamic Host Configuration Protocol
server.
Source Verify
Lease-Query
Throttling
12.2 BC
When the cable source-verify dhcp and no cable arp commands are configured on a
cable interface, problems can occur when viruses, denial of service (DoS) attacks, and
theft-of-service attacks begin scanning a range of IP addresses, in an attempt to find
unused addresses. When the Cisco CMTS router is verifying unknown IP addresses,
this type of scanning generates a large volume of DHCP lease queries, which can
result in a number of problems, such as dropped packets and high CPU utilization of
both the Cisco CMTS router and DHCP server.
To prevent these problems, you can enable filtering of these requests on upstream
interfaces, downstream interfaces, or both. When this feature is enabled, the Cisco
CMTS allows only a certain number of DHCP LEASEQUERY requests for each
service ID (SID) on an interface within the configured interval time period. If a SID
generates more lease queries than the maximum, the router drops the excess number
of requests until the next interval period begins.
For more information on this feature, see the document “Filtering Cable DHCP Lease
Queries”, at the following URL:
•
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122li
mit/122bc/122bc_15/cblsrcvy.htm
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Supported Software Features for the Cisco uBR7100 Series
Table 1-3
Cisco uBR7100 Series Feature List with First Supporting Release Train (continued)
First Cisco IOS
Release
Description
Feature
Support for
dynamic/mobile
hosts
12.1 EC
Allows the CMTS administrator to bring up a PC behind one CM, then move it to
another CM. Adds information for the hosts involved in host tables. To prevent
security breaches, supports pinging the host using the old SID to verify that it has
indeed been moved.
DHCP server is used to verify addresses and can be configured with the cable
source-verify dhcp command; no cable arp should be configured in the CMTS to
prevent it from sending ARP requests.
DOCSIS Feature Support
Concatenation
support
12.1 EC
Combines multiple upstream packets into one packet to reduce packet overhead and
overall latency, as well as increase transmission efficiency. Using concatenation, a CM
needs to make only one bandwidth request for a concatenated packet, as opposed to
making a different bandwidth request for each individual packet. This technique is
particularly effective for real time traffic.
DHCP Client
ID/Remote ID
options
12.1 EC
Allows the Cisco uBR7100 series to report and limit the number of CPEs per
cable interface through command-line interface (CLI) and Simple Network
Management Protocol (SNMP).
Note
This feature is also known as Customer Premises Equipment (CPE)
Limitation.
DOCS-IF-MIB
Update
12.2(15)BC2
The DOCS-IF-MIB (released as RFC 2670) has been updated to conform to the
version 5 of the DOCSIS 2.0 RF MIB Specification
(draft-ietf-ipcdn-docs-rfmibv2-05.txt).
DOCSIS 1.0
Concatenation
Override
12.3 BC
Cisco IOS release 12.3(13a)BC introduces support for the DOCSIS 1.0 concatenation
override feature on the Cisco uBR10012 router. This feature provides the ability to
disable concatenation on DOCSIS 1.0 cable modems, even in circumstances where
concatenation is otherwise supported for the upstream channel.
DOCSIS 1.0 concatenation allows the cable modem to make a single-time slice
request for multiple packets, and to send all packets in a single large burst on the
upstream. Concatenation was introduced in the upstream receive driver in the previous
Cisco IOS releases that supported DOCSIS 1.0 +. Per-SID counters were later added
in Cisco IOS release 12.1(4)CX for debugging concatenation activity.
In some circumstances, overriding concatenation on DOCSIS 1.0 cable modems may
be preferable, and Cisco IOS release 12.3(13a)BC supports either option.
To enable DOCSIS 1.0 concatenation override with Cisco IOS release 12.3(13a)BC
and later releases, use the new docsis10 keyword with the previously supported cable
upstream <n> concatenation command in privileged EXEC mode:
cable upstream <n> concatenation docsis10
Refer to Release Notes for Cisco uBR7100 Series for Cisco IOS Release 12.3 BC:
•
http://www.cisco.com/en/US/products/hw/cable/ps2211/prod_release_notes_list.ht
ml
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Table 1-3
Cisco uBR7100 Series Feature List with First Supporting Release Train (continued)
Feature
First Cisco IOS
Release
Description
DOCSIS 1.0
Constant Bit Rate
(CBR)—DOCSIS
1.0 extension
12.1 EC
Enables better processing of higher priority traffic; new fields in the DOCSIS
configuration file can be used so that when a CM requests a voice SID, the MAC
scheduler on the Cisco uBR7100 series schedules fixed periodic slots on the upstream
for that traffic flow. The CM does not have to contend for these slots, and because the
Cisco uBR7100 series controls the timing of slots, it has precise control over potential
delay and jitter.
DOCSIS 1.0 Media
Access Controller
(MAC) driver
12.1 EC
Supports CableLabs specifications for the MAC sublayer and associated interfaces.
DOCSIS 1.0 QoS
enhancements
12.1 EC
Supports definition of service class profiles according to DOCSIS 1.0:
•
Traffic priority (7, 6, 5, 4, 3, 2, 1, 0) with 7 being the highest
•
Maximum upstream rate in bps
•
Maximum upstream channel burst in minislot
•
Minimum upstream rate in bps
•
Maximum downstream rate in bps
DOCSIS extensions
MIB
12.1 EC
Supports objects related to QoS support for scheduler of DOCSIS-compliant RF
interfaces in the CMTS.
DOCSIS Set-Top
Gateway (DSG) 1.0
12.2 BC
Cisco IOS Release 12.3(9a)BC introduces support for DOCSIS Set-Top Gateway
(DSG) Issue 1.0 on the Cisco uBR7100 series universal broadband router. The
DOCSIS Set-Top Gateway (DSG) feature allows the Cisco CMTS to provide a class
of cable services known as out-of-band (OOB) messaging to set-top boxes (STBs)
over existing DOCSIS networks. This allows MSOs and other service providers to
combine both DOCSIS and STB operations over one, open, vendor-independent
network, without any change to the existing network or cable modems.
DSG is a CableLabs® specification that allows the Cisco CMTS to provide a class of
cable services known as out-of-band (OOB) messaging to set-top boxes (STBs) over
existing Data-over-Cable Service Interface Specifications (DOCSIS) cable networks.
DSG 1.0 allows cable Multi-System Operators (MSOs) and other service providers to
combine both DOCSIS and STB operations over a single, open and
vendor-independent network without requiring any changes to the existing DOCSIS
network infrastructure.
At the time of this Cisco publication, the CableLabs® DOCSIS DSG specification is
in the current status of “Issued” as characterized by stability, rigorous review in
industry and cross-vendor interoperability.
For additional information about configuring and using DSG 1.0 on the Cisco
uBR7100 Series routers, refer to the following document on Cisco.com:
•
DOCSIS Set-Top Gateway for the Cisco CMTS
http://www.cisco.com/en/US/netsol/ns457/networking_solutions_white_paper09
186a00801b3f0f.shtml
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Table 1-3
Cisco uBR7100 Series Feature List with First Supporting Release Train (continued)
First Cisco IOS
Release
Description
Feature
DOCSIS software
infrastructure
12.1 EC
Supports CableLabs specifications for high-speed data-over-cable systems involving
the following categories:
•
RF interfaces between the Cisco uBR7100 series and the cable
network—Downstream and upstream traffic.
•
Data interfaces for cable interfaces and CPE devices, as well as the CMTS
network-side interface between the Cisco uBR7100 series routers and the data
network.
•
Operations support interfaces—Network element management layer interfaces
between the network elements and the operations support systems. Telco return
interfaces—Interfaces between third-party DOCSIS-compliant cable interfaces
and the telco return path(s) when the return path is not provided by the cable
network.
Downstream
channel ID
12.1 EC
Allows all cable interfaces on the cable network to have unique downstream channel
IDs. CMs communicate their downstream ID when making a connection, and not the
downstream frequency.
Downstream
frequency override
12.1 EC
Allows the Cisco uBR7100 series to change the downstream frequency for a
cable interface, overriding the DOCSIS configuration file setting.
Downstream signal
test commands
12.1 EC
Provides the following test capabilities: the cable downstream if-output command is
enhanced with the following options to generate test signals on the downstream
interface:
•
cable downstream if-output prbs shuts down the downstream interface and
outputs a PRBS test signal
•
cable downstream if-output continuous wave shuts down the downstream
interface and outputs an unmodulated carrier signal
The previous cable downstream if-output command has not changed and continues
to output a standard modulated signal.
The no cable downstream if-output command has not changed; it stops all signal
output and shuts down the interface.
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Table 1-3
Cisco uBR7100 Series Feature List with First Supporting Release Train (continued)
Feature
First Cisco IOS
Release
Description
Enhanced Rate
Bandwidth
Allocation (ERBA)
Support for DOCSIS
1.0 Cable Modems
Cisco IOS release 12.3(13a)BC introduces Enhanced Rate Bandwidth Allocation
(ERBA) support for DOCSIS 1.0 cable modems and the Cisco uBR7100 router. ERBA
allows DOCSIS1.0 modems to burst their temporary transmission rate up to the full
line rate for short durations of time. This capability provides higher bandwidth for
instantaneous bandwidth requests, such as those in Internet downloads, without
having to make changes to existing service levels in the QoS Profile.
This feature enables MSOs to set the DOCSIS 1.0 cable modems burst transmissions,
with mapping to overriding DOCSIS 1.1 QoS profile parameters on the Cisco CMTS.
DOCSIS 1.0 cable modems require DOCSIS 1.0 parameters when registering to a
matching QoS profile. This feature enables maximum downstream line rates, and the
ERBA setting applies to all cable modems that register to the corresponding QoS
profile.
Note
QoS definitions must previously exist on the Cisco CMTS headend to support
this feature.
DOCSIS 1.0 cable modems require DOCSIS 1.0 parameters when registering to a
matching QoS profile. This feature enables the maximum downstream burst to be set
in global configuration mode. The max-ds-burst setting applies to all cable modems
that register to the corresponding QoS profile.
ERBA for DOCSIS 1.0 cable modems is supported with these new or enhanced
commands or keywords in Cisco IOS release 12.3(13a)BC:
•
cable qos pro max-ds-burst burst-size
•
show cable qos profile n [verbose]
Refer to Release Notes for Cisco uBR7100 Series for Cisco IOS Release 12.3 BC:
•
Enhanced source
address verification
12.1 EC
Prevents the spoofing of IP addresses by verifying that each upstream data packet
comes from the CM known to be associated with the source IP address in the packet.
The cable source-verify [dhcp] cable interface command specifies that DHCP lease
query requests are sent to verify any unknown source IP address found in upstream
data packets.
Note
EuroDOCSIS
Support
12.1 EC
http://www.cisco.com/en/US/docs/cable/cmts/ubr7100/release/notes/12_3bc/123B
Cu71.html
This feature requires a DHCP server that supports the new LEASEQUERY
message type such as Cisco Network Registrar (CNR) Version 3.01(T).
The Cisco uBR7111E and Cisco uBR7114E routers support the EuroDOCSIS Annex
A standard with 8 MHz PAL or SECAM channel plan operation (similar to
DAVIC/DVB ITU J.83 standard).
The EuroDOCSIS standard specifies a downstream 36.125 MHz interface, with a
8 MHz channel width and interleave factor of I=12, J=17. The card supports a
downstream symbol rate of 6.592 Msymbols/sec at 64 QAM and 256 QAM. The
downstream channel range supported is 85 to 860 MHz; the upstream channel range
supported is 5 to 65 MHz.
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Supported Software Features for the Cisco uBR7100 Series
Table 1-3
Cisco uBR7100 Series Feature List with First Supporting Release Train (continued)
First Cisco IOS
Release
Description
Feature
Extended Upstream
Frequency Ranges
12.2 BC
Cisco IOS Release 12.2(15)BC2 adds support for the extended upstream frequency
range that is used in cable networks in Japan and other areas. This feature also clarifies
the configuration of DOCSIS and EuroDOCSIS networks, so that the router shows
only those upstream and downstream frequencies that are valid for each mode of
operation.
A new CLI command, cable freq-range, was also added to support this feature on the
Cisco uBR-MC16U/X and Cisco uBR-MC28U/X cards. For more information, see the
Support for Extended Upstream Frequency Ranges, at the following URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122limi
t/122bc/122bc_15/mclcjfm.htm
Integrated Time of
Day (ToD) server
12.1 EC
Allows the Cisco uBR7100 series to respond to ToD (RFC 868) queries from
cable interfaces during the registration process.
Modem power
enhancement
adjustments for low
SNR failures
12.1 EC
Allows Cisco uBR7100 series to better adjust when a CM seems to bounce—the CM
requires frequent power adjustments in opposite directions. When this occurs, instead
of making large power adjustments for each correction, the administrator can
configure the Cisco uBR7100 series to calculate the average value of the power
corrections before making power adjustments:
•
cable upstream power-adjust threshold now accepts a range of 0 to 10 dB (the
previous range was 0 to 2 dB).
•
cable upstream power-adjust noise % of power adjustment sets the threshold
value (in percent) for a particular upstream, switching between regular power
adjustments and the noise power adjustment method.
The noise power adjustment method uses an averaging algorithm before sending any
correction.
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Table 1-3
Cisco uBR7100 Series Feature List with First Supporting Release Train (continued)
Feature
First Cisco IOS
Release
Description
Vendor-Specific
Information Field to
Authorize Dynamic
Service Requests
DOCSIS 1.1 cable modems can request additional bandwidth via the DOCSIS 1.1
dynamic services mechanism, by sending dynamic service add (DSA) and dynamic
service change (DSC) messages (known collectively as DSX messages). By default,
the CMTS grants these requests because a DOCSIS-compliant cable modem does not
request services that would violate their provisioned service flows.
However, a cable modem that is using software that is not DOCSIS-compliant, or that
is using software that has been hacked to include unauthorized changes that violate the
DOCSIS specifications, could use dynamic services requests to obtain bandwidth that
the user is not authorized to use. Users could also use dynamic services requests as
part of a denial-of-service attack on the cable network.
To prevent this, Cisco IOS Release 12.2(15)BC2 supports including an optional
vendor-specific information field (VSIF) in the DOCSIS configuration file to enable
or disable DSX requests by the cable modem:
TLV = 43 (VSIF)
SubTLV 12, Length = 1
Value = 0, denies all DSX requests
Value = 1, allows all DSX requests
Refer to Cisco uBR7100 Series - Cisco IOS Release 12.2 BC:
•
http://www.cisco.com/en/US/docs/ios/12_2/12_2b/12_2bc/release/notes/u7108bc1.
html
High Availability Features
N+1 HCCP
Redundancy with
Load Balancing
Intercept Features
12.2 BC
Cisco IOS Release 12.2(15)BC2 supports configuring a cable interface for both load
balancing and N+1 HCCP redundancy.
Access List Support 12.3 BC
for COPS Intercept
Cisco IOS Release 12.3(13a)BC introduces enhanced command-line interface for the
Common Open Policy Service (COPS) feature.
To configure access control lists (ACLs) for inbound connections to all COPS listener
applications on the Cisco CMTS, user the cops listeners access-list command in
global configuration mode. To remove this setting from the Cisco CMTS, us the no
forZzm of this command.
Refer to Release Notes for Cisco uBR7100 Series for Cisco IOS Release 12.3 BC:
•
http://www.cisco.com/en/US/docs/cable/cmts/ubr7100/release/notes/12_3bc/123B
Cu71.html
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Supported Software Features for the Cisco uBR7100 Series
Table 1-3
Cisco uBR7100 Series Feature List with First Supporting Release Train (continued)
First Cisco IOS
Release
Description
Feature
SII—Service
Independent
Intercept
12.3 BC
Cisco CMTS supports the Communications Assistance for Law Enforcement Act
(CALEA) for voice and data. Cisco IOS Release 12.3(13a)BC introduces support for
Service Independent Intercept (SII) on the Cisco uBR7100 CMTS. Cisco SII provides
a more robust level of the lawful intercept (LI) options offered in the Packet Intercept
feature. Cisco SII is the next level of support for judicially authorized electronic
intercept, to include dial access, mobile wireless, tunneled traffic, and Resilient
Transport Protocol (RTP) for voice and data traffic on the Cisco CMTS. SII on the
Cisco CMTS includes these functions:
Packet intercept on specified or unspecified interfaces or ports, including port lists
Packet intercept on virtual interface bundles
Corresponding SNMP MIB enhancements for each of these functions, as intercept
requests are initiated by a mediation device (MD) using SNMPv3
No new CLI commands are provided for this feature in Cisco IOS release
12.3(13a)BC.
Refer to Release Notes for Cisco uBR7100 Series for Cisco IOS Release 12.3 BC:
•
http://www.cisco.com/en/US/docs/cable/cmts/ubr7100/release/notes/12_3bc/123B
Cu71.html
IP Networking
ARP Filtering
12.2 BC
Cisco IOS Release 12.2(15)BC2 adds support for the cable arp filter command,
which enables service providers to filter ARP request and reply packets, to prevent a
large volume of such packets from interfering with the other traffic on the cable
network. For more information, see the Cable ARP Filtering document, at the
following URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122limi
t/122bc/122bc_15/cblarpfl.htm
Cisco IOS Release 12.2(15)BC2b introduces support for the ip-requests-filtered
option, which was added to the show cable arp-filter command to display the specific
Service IDs (SIDs) that are generating or forwarding a minimum number of ARP
packets.
Refer to Cisco uBR7100 Series - Cisco IOS Release 12.2 BC:
•
LLQ—Low Latency 12.3 BC
Queuing
IP Routing
http://www.cisco.com/en/US/docs/ios/12_2/12_2b/12_2bc/release/notes/u7108bc1.
html
See “Upstream Schedule Modes (Optional).”
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Table 1-3
Cisco uBR7100 Series Feature List with First Supporting Release Train (continued)
Feature
Basic wiretap
support
First Cisco IOS
Release
Description
12.1 EC
Provides support for a basic wiretap facility that the United States Federal
Communications Assistance for Law Enforcement Act (CALEA) requires. This
provides a mechanism such that user-to-user traffic can be captured.
The wiretap facility is based on the MAC address of the RF CPE device, so the wiretap
facility can be used for either data or digitized higher priority connections. The feature
is controlled by the new interface command—cable intercept—which requires a
MAC address, an IP address, and a UDP port number as its parameters:
cable intercept[mac-address] ip-address udp-port
When activated, the Cisco uBR7100 series examines each packet for the desired MAC
address. When a matching MAC address is found (for either the origination or
destination endpoint), a copy of the packet is encapsulated into a UDP packet, which
is then sent to the specified server at the given IP address and port.
Bridging Operation
12.1 EC
Performs forwarding of traffic on the basis of the MAC address between the cable and
port adapter interfaces.
Cable modem
multicast
authentication
(RADIUS)
12.1 EC
Permits RADIUS to be used to authenticate subscribers.
Cisco IOS router
operating system
12.1 EC
Performs enhanced route filtering and translation to save network resources and
prevent data from being broadcast to nodes that do not require it.
Integrated Routing
and Bridging (IRB)
12.1 EC
Allows the Cisco uBR7100 series to use bridging on the cable and port adapter
interfaces, while still providing access to routed networks, without having to use a
separate external router.
Nonstop Forwarding 12.2 BC
(NSF) Awareness
The Nonstop Forwarding (NSF) Awareness feature, introduced in Cisco IOS Release
12.2(15)T and inherited by Cisco IOS Release 12.2(15)BC1, allows customer premises
equipment (CPE) routers that are NSF-aware to assist NSF-capable routers perform
nonstop forwarding of packets.
The NSF Awareness feature is supported on three IP routing protocols—Border
Gateway Protocol (BGP), Open Shortest Path First (OSPF), and Integrated
Intermediate System-to-Intermediate System (IS-IS).
Refer to Cisco uBR7100 Series - Cisco IOS Release 12.2 BC:
•
Per modem filters
12.1 EC
Allows the Cisco uBR7100 series to filter incoming packets from individual hosts or
cable interfaces based on the source Media Access Control (MAC) or Internet Protocol
(IP) address. This allows access lists to be specified on a per-interface and per-direction
basis. The packets received from cable interfaces and individual hosts are filtered based
on the cable interface or the host from which the packets are received.
12.1 EC
Allows the Cisco uBR7100 series to register third-party DOCSIS-compliant
telco return cable interfaces, based on the DOCSIS telco return specification. This
allows the network to support two-way and telco return cable interfaces.
(also known as per
modem and per host
access lists)
Telco return
http://www.cisco.com/en/US/docs/ios/12_2/12_2b/12_2bc/release/notes/u7108bc1.
html
Transparent and IRB 12.1 EC
Bridging Operation
Performs forwarding of traffic on the basis of the MAC address between the cable and
port adapter interfaces.
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Table 1-3
Cisco uBR7100 Series Feature List with First Supporting Release Train (continued)
First Cisco IOS
Release
Description
Feature
Upstream Schedule
Modes (Optional)
12.3 BC
With this feature, the user is able to select either Unsolicited Grant Services (UGS) or
Real Time Polling Service (rtPS) scheduling types, as well as packet-based or
TDM-based scheduling. Low latency queueing (LLQ) emulates a packet-mode-like
operation over the Time Division Multiplex (TDM) infrastructure of DOCSIS. As
such, the feature provides the typical tradeoff between packets and TDM: with LLQ,
the user has more flexibility in defining service parameters for UGS or rtPS, but with
no guarantee (other than statistical distribution) regarding parameters such as delay
and jitter.
Refer to Release Notes for Cisco uBR7100 Series for Cisco IOS Release 12.3 BC:
•
http://www.cisco.com/en/US/docs/cable/cmts/ubr7100/release/notes/12_3bc/123B
Cu71.html
Management Features
Cable monitor
12.1 EC
Provides upstream and downstream sniffer capabilities.
Downstream Load
Balancing
Distribution with
Upstream Load
Balancing
12.3 BC
Cisco IOS Release 12.3(17b)BC4 introduces further enhancements to downstream load
balancing, resulting in equalized upstream load balancing group members. This
enhancement synchronizes the pending statistic between different cable interface line
cards in the load balancing group.
This enhancement performs downstream load balancing that accounts for loads on
upstream channels in the same upstream load balancing group, rather than on the basis of
the entire downstream channel load. Prior Cisco IOS releases may not have distributed
cable modems evenly over individual upstream channels, nor in a way that accounted for
downstream and upstream segment loads that account for one another.
This enhancement applies when downstream load balancing occurs on a headend system
with separate upstream load balancing segments; the upstream segments are spread over
multiple downstreams segments. This enhancement provides an alternative downstream
load balancing scheme that accounts and makes use of per-upstream loads rather than total
downstream loads.
For additional information about Load Balancing on the Cisco CMTS, refer to the
following documents on Cisco.com:
•
Load Balancing and Dynamic Channel Change on the Cisco CMTS
http://www.cisco.com/en/US/docs/cable/cmts/troubleshooting_batch9/cmtslbg.h
tml
•
Cisco Broadband Cable Command Reference Guide
http://www.cisco.com/en/US/docs/ios/cable/command/reference/cbl_book.html
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Table 1-3
Cisco uBR7100 Series Feature List with First Supporting Release Train (continued)
Feature
Modem status
display
enhancements
First Cisco IOS
Release
Description
12.1 EC
Enhancements support polling of CMs to obtain parameter and status information on
an ongoing basis. Two new Cisco IOS commands are added to support the feature:
•
cable modem remote configures the router for the polling interval; the no version
of this command disables the status polling.
•
show cable modem remote-query displays the collected information:
– downstream receive power level
– downstream signal to noise ratio
– upstream power level
– micro reflection in dB
Additional or changed show commands include:
•
show cable qos shows cable qos-profile n command, where the optional
argument n can be used to display a specific profile.
•
show int cx/y sid displays more complete Service ID (SID) status information.
•
show cable modem displays a list of options for a single modem to be specified
by entering either the RF CPE device’s IP address or MAC address: SNR
information for each CM on each interface, summary display of the total number
of modems connected for each upstream channel, total number of registered and
unregistered modems for the specified interface or upstream, total number of
offline modems for the specified interface or upstream and status for each offline
modem before it went offline.
•
show cable burst-profile has been removed. Its functions have been incorporated
into the show cable modulation-profile command, which now includes an added
option number that displays the modulation profile number.
•
show cable flap-list and show cable modem now indicate when the
Cisco uBR7100 series has detected an unstable return path for a particular modem
and has compensated with a power adjustment. An asterisk appears in the power
adjustment field for a modem when a power adjustment has been made; an
exclamation point appears when the modem has reached its maximum power
transmit level and cannot increase its power level any further.
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Table 1-3
Cisco uBR7100 Series Feature List with First Supporting Release Train (continued)
First Cisco IOS
Release
Description
Feature
Subscriber Traffic
Management 1.1
12.3 BC
Cisco IOS Release 12.3(9a)BC introduces support for Subscriber Traffic Management
(STM) through Version 1.1 on the Cisco uBR7100 series universal broadband routers.
STM 1.1 supports DOCSIS 1.1-compliant cable modems. The STM feature enables
service providers to identify and control subscribers who exceed the maximum
bandwidth allowed under their registered quality of service (QoS) profiles. STM 1.1
works with Network-Based Application Recognition (NBAR) and Access control lists
(ACLs) to ensure full network performance to other network subscribers that abide by
their service agreements. STM 1.1 also works in conjunction with the Cisco
Broadband Troubleshooter 3.2 to support additional network management and
troubleshooting functions in the Cisco CMTS.
STM 1.1 extends earlier STM functions to monitor a subscriber's traffic on DOCSIS
1.1 primary service flows and supports these additional features:
•
Cisco Broadband Troubleshooter (CBT) 3.2 supports STM 1.1.
•
DOCSIS 1.0-compliant and DOCSIS 1.1-compliant cable modem are supported.
•
Monitoring and application of traffic management policies are applied on a
service-flow basis.
•
Monitoring window duration increased from seven to 30 days.
For additional information about STM 1.1 and Cisco CBT 3.2, refer to the following
document on Cisco.com:
•
Release Notes for Cisco Broadband Troubleshooter Release 3.2
http://www.cisco.com/en/US/products/sw/netmgtsw/ps530/prod_release_notes_l
ist.html
PacketCable and Voice Support Features
PacketCable
12.2 BC
Cisco IOS Release 12.2(15)BC2 supports PacketCable operations on the Cisco
uBR-MC5X20S/U cable interface line cards on the Cisco uBR10012 router, and on the
Cisco uBR-MC16U/X and Cisco uBR-MC28U/X cards on the Cisco uBR7246VXR
router.
In addition, cable interfaces can be configured for both PacketCable operations and for
N+1 HCCP redundancy. The debug packetcable hccp and show packetcable event
commands have been added as part of this support.
Refer to Cisco uBR7100 Series - Cisco IOS Release 12.2 BC:
•
http://www.cisco.com/en/US/docs/ios/12_2/12_2b/12_2bc/release/notes/u7108bc1.
html
Security Features
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Table 1-3
Cisco uBR7100 Series Feature List with First Supporting Release Train (continued)
Feature
Dynamic Shared
Secret
First Cisco IOS
Release
Description
12.2 BC
The Dynamic Shared Secret feature provides service providers a way of providing
higher levels of security for their Data-over-Cable Service Interface Specifications
(DOCSIS) cable networks, by using randomized, single-use shared secrets to verify
the DOCSIS configuration files that are downloaded to each cable modem. The
Dynamic Shared Secret feature is enabled using the cable dynamic-secret interface
configuration command.
The Dynamic Shared Secret feature automatically creates a unique DOCSIS shared
secret on a per-modem basis, creating a one-time use DOCSIS configuration file that
is valid only for the current session. This ensures that a DOCSIS configuration file that
has been downloaded for one cable modem can never be used by any other modem,
nor can the same modem reuse this configuration file at a later time.
This patent-pending feature is designed to guarantee that all registered modems are
using only the quality of service (QoS) parameters that have been specified by the
DOCSIS provisioning system for that particular modem at the time of its registration.
For information on the Dynamic Shared Secret feature, see the Configuring a Dynamic
Shared Secret for the Cisco CMTS document, at the following URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122limi
t/122bc/122bc_15/ubrdmic.htm
Encrypted Baseline
Privacy key
exchange
12.1 EC
Supports full DOCSIS 1.0 BPI specifications
40-bit and 56-bit
Baseline Privacy
Data Encryption
Standard (DES)
12.1 EC
The Cisco uBR7100 series supports 40-bit and 56-bit encryption/decryption. When
encryption/decryption is enabled, 56-bit is the default. If necessary, administrators can
force the Cisco uBR7100 series to generate a 40-bit DES key, where the DES key that
is generated and returned masks the first 16-bits of the 56-bit key to zero in software.
Note
Telco return
RADIUS
enhancements
12.1 EC
Requires software images that support the BPI feature to be set at the CMTS
and CM.
Enhancements provide additional authentication information, allowing an
administrator to determine if a subscriber dialed a number that requires special billing
arrangements (such as a toll-free number). If a telco return customer is being
authenticated by a Terminal Access Controller Access Control System Plus
(TACACS+) or RADIUS server, and if the number dialed by the CM is being
redirected to another number for authentication, the system can include the original
number in the information sent to the authentication server. The original number can
be sent as a Cisco Vendor Specific Attribute (VSA) for TACACS+ servers and as
RADIUS Attribute 93 (Ascend-Redirect-Number) for RADIUS servers.
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Table 1-3
Cisco uBR7100 Series Feature List with First Supporting Release Train (continued)
First Cisco IOS
Release
Description
Feature
Upstream address
verification
12.1 EC
Supports verification of cable interface and PC addresses to ensure cable interface
SID and MAC addresses are consistent; this helps ensure IP addresses are not spoofed.
A PC behind a cable interface is assigned an IP address from the DHCP server. If a
user on a second PC/cable interface statically assigns the same IP address to a PC, the
Cisco uBR7100 series finds this case to help block the spoofing user. Using the CLI,
administrators can determine the IP and MAC address of a given cable interface, and
the SID number that shows the IP and MAC addresses of all devices learned in the
cable interface MAC table. Using the service provider customer databases,
administrators can cross reference the spoofing cable interface and PC and prevent
usage.
SNMP Features and Enhancements
CISCO-NBAR-PRO 12.2(15)BC2
TOCOL-DISCOVE
RY-MIB
Cisco IOS Release 12.2(15)BC2 adds support for the
CISCO-NBAR-PROTOCOL-DISCOVERY-MIB to the Cisco uBR7100 series and
Cisco uBR7246VXR universal broadband routers. This allows service providers to
use SNMP requests to configure and monitor the Network-Based Application
Recognition (NBAR) feature.
For more information about NBAR, see the Network-Based Application Recognition
and Distributed Network-Based Application Recognition document, at the following
URL:
http://www.cisco.mn/en/US/products/ps6616/products_ios_protocol_group_home.ht
ml
For more information about the CISCO-NBAR-PROTOCOL-DISCOVERY-MIB, see
the Network-Based Application Recognition Protocol Discovery Management
Information Base document, at the following URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122t/12
2t15/ftpdmib.htm
RF Interface
Management
Information Base
(MIB)
12.1 EC
Improves object support for SNMP traps; traps are the mechanisms used to
automatically send alarms for certain network events.
Service Class
Setting Using
SNMP
12.1 EC
Supports objects related to class of service.
Simple Network
12.1 EC
Management
Protocol (SNMP) v3
SNMP version 3 offers enhanced security features and increases interoperability. The
implementation set of MIBs allows the SNMP manager to gather data such as system
card descriptions, serial numbers, hardware and software revision levels, and slot
location.
Support for RFC
2233
(RF Interface MIB)
Support DOCSIS OSSI Required Objects in RFC 2233 for the Cisco uBR7100 series.
12.1 EC
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Table 1-3
Cisco uBR7100 Series Feature List with First Supporting Release Train (continued)
Feature
First Cisco IOS
Release
Description
Support for RFC
12.1 EC
2665 for
Cisco uBR7100
Series
Spectrum Management Features
Support DOCSIS OSSI Required Objects in RFC 2665 for the Cisco uBR7100 series.
Dynamic upstream
modulation
12.1 EC
Provides improved performance using proactive spectrum management functions.
Spectrum
management
phases 1 and 2
12.1 EC
Supports the following spectrum management capabilities to specify the rules the
system uses when hopping to another frequency when no clean frequency band is
available:
•
Combined blind and time scheduled reassignment:
– Blind hop—No “look ahead” capabilities, but some specifications on
frequency reassignment based on the number of lost station management
messages exceeding a threshold (default=10).
– Time scheduled—Frequency reassignment based on time of day or week.
Guided frequency hop—Assigning explicit frequency subbands and associated
input power levels in a spectrum group.
Testing, Troubleshooting and Diagnostic Features
•
Cisco Broadband
Troubleshooter
12.3 BC
Cisco IOS Release 12.3(9a)BC introduces support for the Cisco Broadband
Troubleshooter (CBT) Version 3.2 on the Cisco uBR7100 series universal broadband
router. Multiple Service Operators (MSO) provide a variety of services such as TV,
video on demand, data, and voice telephony to subscribers. Network Administrators
and radio frequency (RF) technicians need specialized tools to resolve RF problems in
the MSO’s cable plant. Cisco Broadband Troubleshooter 3.2 (CBT 3.2) is a simple,
easy-to-use tool designed to accurately recognize and resolve such issues.
The user can select up to three different cable modems (CMs) under the same CMTS
or three different upstreams under the same CMTS. In addition, CBT 3.2 introduces
the ability to display upstreams and cable modems combined (mixed) on the same
trace window for monitoring and for playback.
Note
CBT 3.2 resolves the former CBT 3.1 caveat CSCee03388. With CBT 3.1,
trace windows did not support the mixing of upstreams or cable modems.
Refer to Release Notes for Cisco Broadband Troubleshooter Release 3.2:
•
http://www.cisco.com/en/US/products/sw/netmgtsw/ps530/prod_release_notes_list
.html
VLAN Features
Interswitch Link
(ISL) bridging
(noncable
interfaces)
12.1 EC
Provides support for the ISL feature—Cisco protocol used to interconnect multiple
routers and switches and maintain Virtual Local Area Network (VLAN) information
as traffic is conveyed between the routers and switches.
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Table 1-3
Cisco uBR7100 Series Feature List with First Supporting Release Train (continued)
First Cisco IOS
Release
Description
Feature
Transparent LAN
Service
12.2 BC
Cisco IOS Release 12.2(15)BC2 enhanced the existing support for Transparent Lan
Services (TLS), which allows the Cisco CMTS to create Layer 2 tunnels for traffic to
and from cable modems. This allows customers to create their own virtual local area
network (VLAN) using any number of cable modems in multiple sites.
In addition to the ATM PVC Mapping, which was previously supported, Cisco IOS
Release 12.2(15)BC2 added the ability to map a cable modem’s MAC address to an
IEEE 802.1Q VLAN on a specific Ethernet interface, so that all traffic from the cable
modem is tagged with the specified VLAN ID. Service providers can now map cable
modem traffic onto an ATM PVC or onto an Ethernet IEEE 802.1Q VLAN, depending
on their customer’s specific needs.
For more information on this service, see the Transparent LAN service over Cable
document, at the following URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122limi
t/122bc/122bc_11/sidatmpv.htm
VPN Features
TAG Switching
Support on Cable
Interfaces
12.1 EC
Supports enhancements made to tags placed on the fronts of packets that contain
forwarding information used for making switching decisions for cable interfaces. A
tag switching infrastructure combines advanced routing protocol capabilities to define
IP VPNs by selectively advertising IP reachability information to just those
subscribers within the same VPN or extranet on a cable interface.
WAN Optimization and Service Features
MLPPP Support
12.3 BC
The Cisco IOS Multilink Point-to-Point Protocol (MLPPP) feature is now supported
for selected line cards and port adapters on the Cisco uBR7100 series, which share the
same MLPPP code as the Cisco 7200 series. There is no new hardware or software for
MLPPP in this release.
MLPPP combines one or more physical interfaces into a virtual “bundle” interface.
The bandwidth of the bundle interface is equal to the sum of the component links’
bandwidth. This allows service providers to make the step from T1 and E1 lines to
affordable T3 and E3 speeds.
MLPPP is configured not on a cable interface, but on the T1/E1 link.
Refer to Release Notes for Cisco uBR7100 Series for Cisco IOS Release 12.3 BC:
•
Per SID bandwidth
request/grant
counters
12.1 EC
http://www.cisco.com/en/US/docs/cable/cmts/ubr7100/release/notes/12_3bc/123B
Cu71.html
Promotes better control of higher priority traffic, permitting per-SID bandwidth
requests and grants. Profiles can be customized for scheduling parameters required at
subscriber sites for the service offering. The show interface cx/0 upstream number
command now supports a verbose option that displays:
•
Number of bandwidth requests successfully received by the Cisco uBR7100 series
from the specified SID on the specified cable interface
•
Number of grants issued by the Cisco uBR7100 series to the specified SID
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Note
Refer to the Cisco IOS command reference master index for a detailed listing of all Cisco IOS releases
and supported features.
DOCSIS and CMTS Interoperability
The Cisco uBR7100 series routers support both the DOCSIS and EuroDOCSIS specifications,
depending on the model. The Cisco uBR7111 and Cisco uBR7114 routers support DOCSIS operations,
and the Cisco uBR7111E and Cisco uBR7114E routers support EuroDOCSIS operations. The following
sections describe each standard in more detail.
DOCSIS Cable Plants
When using the DOCSIS specification, a cable plant modulates and demodulates data using 6-MHz
downstream channels in the 54 to 860-MHz range and upstream channels in the 5 to 42 MHz range. The
cable interface supports NTSC channel operation, using standard (STD), Harmonic Related Carrier
(HRC), or Incremental Related Carrier (IRC) frequency plans conforming to EIA-S542.
NTSC uses a 6 MHz-wide modulated signal with an interlaced format of 25 frames per second and 525
lines per frame. NTSC is compatible with CCIR Standard M. PAL, used in West Germany, England,
Holland, Australia, and several other countries.
Note
Cisco 6-MHz products can be used in Cisco 8-MHz cable plants. The products, however, operate at a
maximum downstream bandwidth of 27 Mbps, ignoring 2 MHz of available channel width, and limiting
upstream channel choices to the range below 42 MHz.
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DOCSIS-compliant cable plants that support North American channel plans use ITU J.83 Annex B RF.
Figure 1-1 illustrates a DOCSIS two-way and telco-return architecture.
Figure 1-1
DOCSIS Two-Way and Telco-Return Architecture
Distribution hub or headend
Operation
support system
Telco return
access
Cable modem
termination system
(CMTS)
Distribution
network
Node
Controller
Data
Node
Coax
Mod
50-860 MHz
Port
Adapter
5-42MHz
NTSC
Cable
modem
Fiber Node
Rx
Demod
WAN
Backbone
network
NTSC
Network
termination
Tx
Data
Local
server
facility
Data over
cable service
specification
(DOCSIS)
WAN
Security &
access
controller
Upstream
splitter
and filter
bank
Upstream
RF interface
Remote
server
facility
RF
interface
Telco
return
Cable modem
telco return
interface
34972
PSTN
Downstream
RF interface
Video 1
Video 2
Larger cable companies typically have high-speed fiber backbones that carry Internet data, voice, and
video between the following cable company facilities:
•
Regional processing centers
•
Headends
•
Hubs
The fiber backbone can be made up of OC-3 (155 Mbps) to OC-48 (2488 Mbps) Synchronous Optical
Network (SONET) or Asynchronous Transfer Mode (ATM) rings. The backbone network can connect to
other networks, including the Public Switched Telephone Network (PSTN), other cable system
backbones, or to public Internet interconnect points that multiple ISPs use.
The CMTS Media Access Control (MAC) domain typically includes one or more downstream paths and
one or more upstream paths. Depending on the CMTS configuration, the CMTS MAC domain can be
defined to have its downstreams on one cable modem card with its upstreams on another card, or one or
more CMTS MAC domains per cable modem card.
Cisco provides high-speed routers to route interactive traffic between the backbone and Ethernet in the
headend internal network. Signaling protocols maintain the network intelligence needed to route traffic
optimally, automatically building and maintaining routing tables to direct traffic and signal failures for
rerouting in the network.
Border Gateway Protocol (BPG) typically operates between the cable operator’s regional network and
external networks, providing routing information exchange between different networks. The Open
Shortest Path First (OSPF) protocol is used in regional networks usually. Cisco routers incorporate
Cisco IOS software, which offers advanced software features, including quality of service (QoS),
Weighted Fair Queuing (WFQ), and IP multicast.
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The data path for DOCSIS networks is divided into the downstream (traffic sent from the CMTS to the
CM) and the upstream (traffic sent from the CM to the CMTS). Because 90% of traffic in a typical
Internet session is sent from the Internet to the user, the downstream is assigned the majority of the
bandwidth allocated to each user.
A single downstream can support thousands of users, depending on their particular service needs. All of
the users on a downstream might share the same upstream (as would be the case with a Cisco uBR7111
installation), or they might be split across several upstreams (as would be the case with a Cisco uBR7114
installation). For installations that have not been upgraded to two-way operations, the upstream can be
provided through a telco-return connection, where the cable modem directs the upstream traffic through
a modem that connects to the headend through the public telephone switched network (PTSN).
The following sections describe the downstream and upstream signals in more detail.
Downstream Signals
Downstream signals are modulated using QAM-64 or QAM-256 quadrature amplitude modulation,
based on the cable interface card used, your cable plant, and the significance of the data. DOCSIS
defines the messages and data types for CMTS to CM (or CM in an STB) communications. All CMs
listen to all frames transmitted on the downstream channel on which they are registered and accept those
where the destinations match the units themselves or the devices that each CM supports.
The Cisco uBR7100 series CMTS supports multicast groups using standard protocols such as Protocol
Independent Multicast (PIM), Distance Vector Multicast Routing Protocol (DVMRP), and Internet
Group Management Protocol (IGMP) to determine if multicast streams are to be forwarded to a
prescribed downstream CM or STB, or a multicast routing peer.
The Cisco uBR7100 series software periodically sends MAC (Media Access Control) allocation and
management messages—known as MAPs—to all CMs on the network, defining the transmission
availability of channels for specific periods of time. The MAP rate is fixed—every 2 milliseconds.
Different transmission intervals are defined that associate an interval with a Service Identifier (SID).
SIDs define the devices allowed to transmit, and provide device identification and class of service
management. Software defines what type of transmission is allowed during the interval.
The CMTS system administrator typically assigns one or more SIDs to each CM, corresponding to the
classes of service the CM requires. Each MAP is associated with a particular upstream channel. The SID
concept supports multiple data flows and use of protocols such as Resource Reservation Protocol
(RSVP) that allows IP backbone QoS features to be extended to the CMTS. The CMTS schedules the
times granted for sending and receiving packets, and if defined, manipulates the type of service (ToS)
field in the IP packet header to accommodate QoS.
Note
Cisco uBR7100 series software supports extensions to DOCSIS 1.0 to operate with DOCSIS 1.0-based
CMs or cable RF CPE devices (such as Cisco uBR924 cable access routers or Cisco uBR910 cable data
service units) that also support DOCSIS 1.0 extensions.
Tip
DOCSIS 1.0 extensions address the problem of QoS for VoIP until the DOCSIS 1.1 specification is
finalized. Currently, only certain vendors offer products that support DOCSIS 1.0 extensions.
DOCSIS 1.0 extensions build intelligence into the MAP file, which the CMTS sends to voice-enabled
CMs to address jitter and delay. The extensions support unsolicited grants which are used to create a
constant bit rate-like stream between the CMTS and the CM, in contrast to typical data applications
where CMs request grants from the CMTS before they can transmit upstream.
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Upstream Signals
The upstream channel is characterized by many CMs (or CMs in STBs) transmitting to the CMTS. These
signals typically operate in a burst mode of transmission. Time in the upstream channel is slotted.
The CMTS provides time slots and controls the usage for each upstream interval. The CMTS sends
regular mappings of minislot structure in downstream broadcast MAP messages. The CMTS allocates
contention broadcast slots that all CMs can use, and also allocates upstream minislots for unicast or
noncontention data from specific CMs.
The CMTS allocates two basic types of contention slots on the upstream:
•
Initial ranging slots that CMs use during their initialization phase to join the network. When the
CMTS receives an initial ranging request from a CM using this kind of slot, the CMTS subsequently
polls the CM, and other operational CMs, in unicast, noncontention station maintenance slots. Refer
to the“Automatic Provisioning of Cable Modems” section on page 1-29 for CM provisioning and
initialization processes.
•
Bandwidth-request minislots that CMs use to request data grants from the CMTS to send data
upstream in noncontention mode. Any CM can use this type of minislot to request a data grant from
the CMTS.
The stream of initial ranging slots and bandwidth request minislots comprise two separate contention
subchannels on the upstream. Cisco uBR7100 series software uses a “dynamic bandwidth-request
minislots-per-MAP” algorithm to dynamically control the rate of contention slots for initial ranging and
bandwidth-requests. The CMTS uses a common algorithm to vary backoff parameters that CMs use
within each of the two upstream contention subchannels. The CMTS uses these algorithms to
dynamically determine the initial ranging slots and bandwidth-request minislots to allocate on the slotted
upstream.
When power is restored after a catastrophic power failure, a large number of CMs attempt to join the
network simultaneously. This represents an impulse load on the initial ranging subchannel. The CMTS
increases the frequency of initial ranging slots so that CMs can quickly join the network.
During high upstream data loads, the CMTS conserves the scarce upstream channel bandwidth resource
and is more frugal in introducing upstream initial ranging slots. The CMTS schedules bandwidth-request
minislots at low loads to provide low access delay. At high upstream loads, the CMTS reduces the
number of contention-based request minislots in favor of data grants, while maintaining a minimum
number of request slots.
Note
The system default is to have the automatic dynamic ranging interval algorithm enabled, automatic
dynamic ranging backoff enabled, and data backoffs for each upstream on a cable interface. Commands
to configure the dynamic contention algorithms include:
[no] cable insertion-interval [automatic [Imin [Imax]] in msecs
[no] cable upstream port number range backoff [automatic] | [start | end]
[no] cable upstream port number data-backoff [automatic] | [start | end]
Caution
In general, Cisco discourages adjusting default settings. Only personnel who have received the necessary
training should attempt to adjust values.
The Cisco uBR7100 series equipment periodically broadcasts upstream channel descriptor (UCD)
messages to all CMs. These messages define upstream channel characteristics that include upstream
frequencies, symbol rates and modulation schemes, forward error correction (FEC) parameters, and
other physical layer values.
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Upstream signals are demodulated using quadrature phase shift keying (QPSK) or quadrature amplitude
modulation (QAM). QPSK carries information in the phase of the signal carrier, whereas QAM uses both
phase and amplitude to carry information.
Tip
If your cable plant is susceptible to ingress or noise, QPSK is recommended based on the importance of
the data. Frequencies below 20 MHz are more susceptible to noise and might require lower symbol rates.
Higher frequencies might be able to support higher rates and use QAM modulation instead.
Automatic Provisioning of Cable Modems
A key component of DOCSIS networks is the ability to automatically provision each CM or STB as it
comes online. To allow for this, the systems administrator creates DHCP and DOCSIS configuration
files on the appropriate servers such that each CM or CM in an STB on the network, when initialized,
can transmit a DHCP request, receive its IP address, obtain its TFTP and TOD server addresses, and
download its DOCSIS configuration file (and updated software image, if needed).
The automatic provisioning scenario uses the following servers, which must be available to the CM
through the cable interface:
•
DHCP server—The CM must contact a DHCP server through the cable interface to obtain its IP
address and other information, such as the default gateway and TFTP server from which to download
its DOCSIS configuration file. If the CM cannot contact the DHCP server, it refuses to come online
and restarts the registration process.
•
TFTP server—The CM must download its DOCSIS configuration file from a TFTP server (as
specified in RFC 1350) that is accessible through the cable interface. If the CM cannot download
the DOCSIS configuration file, it refuses to come online and restarts the registration process. The
TFTP server can be a separate workstation (such as a Unix or Windows NT computer), or the
Cisco uBR7100 series router can also operate as a TFTP server for smaller installations.
Using information in the DOCSIS configuration file, the CM can also use the TFTP server to
download an updated software image or another configuration file (such as a Cisco IOS
configuration file).
Note
•
Note
•
Most Unix-based systems include a TFTP server but it must be enabled by modifying the
inetd.conf file. TFTP server for the Microsoft Windows NT and 2000 operating systems might
be part of the operating system, depending on how it was installed, or a TFTP server can be
downloaded from ftp.cisco.com.
ToD server—The CM automatically attempts to connect to a ToD server (as specified in RFC 868)
to obtain the current time so it can accurately timestamp its log and other messages. However, this
server is optional, and if the CM cannot connect to the ToD server within a specified number of
retries, the CM will abandon the attempt and continue with the provisioning process.
A TOD server is typically embedded in systems using the Unix operating system and is
automatically enabled through the inetd utility. Microsoft Windows NT and 2000 do not include
a ToD server, but public domain versions of this software are available for download several sites
on the Internet.
Log server—The CM can be optionally configured to send system log messages to a SYSLOG
server. This is useful but not required for DOCSIS operations.
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•
Security and authentication servers—These servers are optional for two-way installations but are
required for a telco-return installation.
DOCSIS 1.0-based CMs cannot connect to the broadband network until the following processes occur:
•
The CM initializes and ranges through available frequencies until it finds the first frequency that it
can use to communicate to the CMTS—known as scanning for a downstream channel.
•
The CM obtains upstream parameters and performs ranging.
•
The CM goes through the DHCP server process and establishes IP connectivity, time of day (TOD,
optional), and security (optional). At this point, the CM cannot determine if it is communicating on
the correct channel.
•
The CM receives a DOCSIS configuration file from the Trivial File Transfer Protocol (TFTP) server.
One of the parameters in the DOCSIS configuration file tells the CM which channel it can use.
•
The CM registers with the CMTS.
•
If the network supports DOCSIS baseline privacy interface (BPI) or other secure data sets,
encryption/decryption processes are initialized.
•
The CM is ready for normal operations. Once initialized and operational, CMs send requests to
initiate data transmission to the CMTS.
The CMTS system administrator or customer service representative ensures appropriate databases
are updated to activate and support the new subscriber account in the provisioning, billing, or
network management systems in use for the network. Each CM or STB serial number and MAC
address is typically stored in the billing and administrative system.
Initial and station maintenance management messages are sent to maintain communications between
CMs and the CMTS. The following is a typical sequence of messages:
1.
An offline CM powers up and brings up its cable interface.
2.
The CM begins searching on the cable interface for an available downstream frequency.
3.
The CM continues searching the downstream frequencies until it finds an active and available
frequency and locks on to that frequency.
4.
The CMTS sends one or more Upstream Channel Description (UCD) messages to the CM
containing information about the upstream channel it should use.
5.
The CM scans each upstream channel identified in the UCD messages, and if a usable channel is
found, it obtains the bandwidth allocation map for the channel. If no usable channel is found, the
CM attempts to lock on another downstream.
6.
The CM begins its initial ranging, using a temporary identifier on the upstream, to obtain its
permanent Service ID (SID) and initial upstream frequency and power levels.
7.
When ranging is successful, the CM transmits a DHCP request on the cable interface.
8.
The DHCP server receives the DHCP request and replies with a DHCP reply that contains the
information appropriate for this particular CM (IP address, default gateway, ToD server address,
TFTP server address, and so forth).
9.
The CM then contacts the ToD server to obtain a current timestamp. This step is optional but is
recommended because it allows the CM to timestamp its log and other messages, which can be
helpful in troubleshooting problems and managing the network.
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Note
The initial DOCSIS 1.0 specification required that the CM successfully obtain a response from
the ToD server before going online. Later versions of the specification made this optional—if
the CM cannot contact the ToD server after a certain number of attempts, it continues as is with
the provisioning cycle.
10. The CM also contacts the designated TFTP server to obtain its DOCSIS configuration file. If a valid
DOCSIS configuration file is received, the CM configures itself accordingly.
11. If specified in the DOCSIS configuration file, the CM enables BPI encryption and negotiates with
the CMTS for the proper key values.
12. The CM also performs any other steps specified by the DOCSIS configuration file, such as
downloading a new software image or downloading a secondary configuration file (for example,
downloading a Cisco IOS configuration file).
13. The CM then goes online and enters the maintenance state, passing traffic to and from its connected
CPE devices.
EuroDOCSIS Cable Plants
The EuroDOCSIS standard builds on the DOCSIS protocol, adding support at the physical layer for PAL
and SECAM channel plans. PAL uses a 625-line scan picture delivered at 25 frames per second where
the color carrier phase definition changes in alternate scan lines. SECAM uses an 819 line scan picture
that provides better resolution than PAL's 625-line and NTSC's 525-line resolutions.
The configuration and setup of EuroDOCSIS-based cable plants is similar to those of DOCSIS plants,
except that they use the EuroDOCSIS J.112 (Annex A) standard, which uses a similar physical layer as
Digital Audio Video Council/Digital Video Broadcast (DAVIC/DVB) J.83 Annex A networks.
EuroDOCSIS operation permits full bandwidth utilization of the 8 MHz downstream channel in the
85-to-860 MHz range, allowing up to 50 Mbps throughput. EuroDOCSIS also offers an upstream
frequency selection of 5 to 65 MHz, instead of the 5 to 42 MHz range used in DOCSIS networks.
Caution
The Cisco uBR7111E and Cisco uBR7114E routers support only Annex A operation and should not be
used in production cable plants that support a 6 MHz channel plan.
A typical EuroDOCSIS architecture has four subsystems:
•
High-speed fiber backbone—Carries Internet data, voice, and video between regional processing
centers, headends, and hubs.
•
Headend—Aggregates content at the national and regional level and sends it to the fiber backbone.
•
Hub—Combines regional programming with local content and sends that combined content to the
cable network.
•
Interactive STBs with integrated EuroDOCSIS CMs—Connects subscribers to the cable network.
Video sources are Motion Picture Experts Group (MPEG) encoded and then fed into an MPEG
multiplexer that packs the MPEG video streams into a single stream. This stream is uplinked to a satellite
and then downlinked to multiple headends, which then distribute the MPEG stream directly onto the
HFC plant.
The STB receives signals from the cable network and displays them on a television. An STB with
EuroDOCSIS CM functionality supports two-way interactivity. Inside the EuroDOCSIS STB are two
tuners:
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•
One handles MPEG-2 video, audio, broadcast control data, and broadcast service data.
•
The other supports DOCSIS IP data. The return path is implemented with EuroDOCSIS.
EuroDOCSIS STB Support
Depending on the network configuration, servers that support Internet-enhanced video services—DTV
application servers, user data servers, system management servers—and other tools and applications, are
required to enable cable operators to deliver centrally managed services through STBs.
See the “Automatic Provisioning of Cable Modems” section on page 1-29. APIs need to be set up to
allow EuroDOCSIS servers to communicate with the CSRC directory to obtain such information as IP
addresses, user names, and subscription levels.
After registered subscribers receive a EuroDOCSIS-based STB, they can connect up the STB. Automatic
configuration begins when the CM in the STB is detected and the CSRC DHCP server establishes IP
connectivity and the basic IP configuration. As part of this initialization, the DHCP server transmits to
the client STB, binding information for other resources such as TOD and TFTP servers.
When using this initial configuration, the DOCSIS CM uses TFTP to download its default DOCSIS
configuration file, such as the DOCSIS options associated with the STB vendor subnet and CMTS. When
minimally configured, the STB will register with the Cisco uBR7100 series router and create an
associated object in the LDAP directory. The subscriber can then access the Cisco User Register web
user interface to select one or more of the service packages the cable operator offers.
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Configuring the Cisco CMTS for the First Time
This chapter describes how to start up and configure the Cisco uBR7100 series CMTS for the first time.
The chapter contains the following sections:
•
“Preparing for Configuration” section on page 2-1
•
“Understanding Configuration Fundamentals” section on page 2-2
•
“Configuring the Cisco uBR7100 Series CMTS Using AutoInstall” section on page 2-7
•
“Configuring Using the setup Facility” section on page 2-7
•
“Configuring Using the Configuration Mode” section on page 2-15
•
“Using the Setup Facility for Cable Interfaces” section on page 2-17
•
“Checking Your Settings and Reviewing Your Configuration Changes” section on page 2-24
•
“Where to Go Next” section on page 2-25
Preparing for Configuration
Complete these prerequisite steps before you power on and configure the Cisco uBR7100 series router:
•
Ensure your network supports reliable broadband data transmission. Your plant must be swept,
balanced, and certified based on NTSC or appropriate international cable plant recommendations.
Ensure your plant meets all DOCSIS or EuroDOCSIS downstream and upstream RF requirements.
•
Ensure your Cisco uBR7100 series router is installed according to the instructions in the hardware
installation guide that came with your CMTS. The chassis must contain at least one port adapter to
provide backbone connectivity, and one Cisco cable modem card to serve as the RF cable TV
interface.
•
Ensure all other required headend or distribution hub routing and network interface equipment is
installed, configured, and operational (based on the supported services). This includes:
– all routers
– servers (DHCP, TFTP, and ToD)
– network management systems
– other configuration or billing systems, depending on your applications, including gatekeepers
and gateways; backbone and other equipment for VPN support; dial-up access servers,
telephone circuits and connections.
– other equipment if supporting telco return
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Understanding Configuration Fundamentals
•
Ensure DHCP and DOCSIS configuration files have been created and pushed to appropriate servers
so that each cable modem, when initialized, can:
– transmit a DHCP request
– receive an IP address
– obtain TFTP and ToD server addresses
– download a DOCSIS configuration file (or updated software image if using Cisco uBR924 cable
access routers or Cisco uBR910 cable data service units in your network)
•
Ensure customer premises equipment (CPE)—cable modems or set top boxes, PCs, telephones, or
facsimile machines—meet requirements for your network and service offerings.
•
Be familiar with your channel plan to assign appropriate frequencies. Outline your strategies for
setting up bundling or VPN solution sets if applicable to your headend or distribution hub. Know
your dial plan if using H.323 for VoIP services and setting up VoIP-enabled CM configuration
files.As appropriate, obtain:
– passwords
– IP addresses
– subnet masks
– device names
After these prerequisites are met, you are ready to configure the Cisco uBR7100 series CMTS. This
includes, at a minimum, configuring a host name and password for the Cisco uBR7100 series router and
configuring the CMTS to support IP over the cable plant and network backbone.
Understanding Configuration Fundamentals
This section describes the basic parameters of using passwords, and initial configuration utilities that the
Cisco uBR7100 series routers support:
•
“Using the Enable Secret and the Enable Password” section on page 2-3
•
“Configuring the Cisco uBR7100 Series CMTS Using AutoInstall” section on page 2-7
•
“Configuring Using the setup Facility” section on page 2-7
•
“Configuring Using the Configuration Mode” section on page 2-15
Note
These sections provide minimal configuration instructions. For additional configuration information,
refer to subsequent chapters in this guide. For examples of Cisco uBR7100 series configuration files,
refer to the Chapter 4, “Configuring Basic Broadband Internet Access.”
Tip
Be sure you have appropriate addresses and values based on your network before you attempt to
configure the router. Enter the show version command to display the release of Cisco IOS software on
your router.
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Using the Enable Secret and the Enable Password
The Cisco uBR7100 series router is administered using the Cisco command interpreter, called the EXEC
mode. You must boot and log in to the router before you can enter an EXEC command.
Step 1
Step 2
Connect a terminal to the console port of the Cisco uBR7100 series router and establish a terminal
session. You can open a Terminal application (Hyper Terminal) on a PC as follows:
a.
Connect using: Direct to Com 1
b.
Set bits per second: 9600
c.
Set data bits: 8
d.
Set parity: none
e.
Set stop bit: 1
f.
Set flow control: none
Power on the Cisco uBR7100 series router. The following prompt displays:
Would you like to enter the initial dialog?[yes]:no
Step 3
Enter no to choose the normal operating mode of the router. The user EXEC prompt displays:
Router>
Note
For security purposes, the EXEC has two levels of access to commands: user EXEC mode and privileged
EXEC mode. The commands available at the user level are a subset of those available at the privileged
level.
Tip
Because privileged-level EXEC commands can change the configuration of the router, password-protect
these commands to prevent unauthorized use.
At the EXEC prompt, enter one of the following two commands to set password protection:
•
enable secret password (which is a very secure, encrypted password)
•
enable password (which is a less secure, nonencrypted password)
To gain access to privileged-level commands, enter the desired password.
Note
An enable secret password can contain from 1 to 25 uppercase and lowercase alphanumeric characters.
An enable password can contain any number of uppercase and lowercase alphanumeric characters. A
number cannot be the first character. Spaces are valid password characters; for example, “two words” is
a valid password. Leading spaces are ignored. Trailing spaces are recognized. Alphanumeric characters
are recognized as uppercase or lowercase.
Passwords should be different for maximum security. If you enter the same password for both during the
setup script, the system will accept it, but you will receive a warning message indicating that you should
enter a different password.
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Replacing or Recovering a Lost Password
This section describes how to recover a lost enable or console login password, and how to replace a lost
enable secret password on your Cisco uBR7100 series router.
Note
It is possible to recover the enable or console login password. The enable secret password is encrypted,
however, and must be replaced with a new enable secret password.
Overview of the Password Recovery Procedure
Following is an overview of the general steps in the password recovery procedure:
Step 1
If you can log in to the router, enter the show version command to determine the existing configuration
register value.
Step 2
Press the Break key to get to the bootstrap program prompt (ROM monitor). You might need to reload
the system image by power cycling the router.
Step 3
Change the configuration register so that the following functions are enabled:
– Break
– ignore startup configuration
– boot from Flash memory
Note
The key to recovering a lost password is to set the configuration register bit 6 (0x0040) so that
the startup configuration (usually in NVRAM) is ignored. This allows you to log in without
using a password and to display the startup configuration passwords. Cisco recommends setting
the configuration register to 0x142.
Step 4
Power cycle the router by turning power OFF and then back ON.
Step 5
Log in to the router and enter the privileged EXEC mode.
Step 6
Enter the show startup-config command to display the passwords.
Step 7
Recover or replace the displayed passwords.
Step 8
Change the configuration register back to its original setting.
Note
To recover a lost password if Break is disabled on the router, you must have physical access to the router.
Details of the Password Recovery Procedure
Complete the following steps to recover or replace a lost enable, enable secret, or console login
password:
Step 1
Attach an ASCII terminal to the console port on your Cisco uBR7100 series router.
Step 2
Configure the terminal to operate at 9600 baud, 8 data bits, no parity, and 2 stop bits.
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Step 3
If you can log in to the router as a nonprivileged user, enter the show version command to display the
existing configuration register value. Note the value for later use.
If you cannot log in to the router at all, continue with the next step.
Step 4
Press the Break key or send a Break from the console terminal.
•
If Break is enabled, the router enters the ROM monitor, indicated by the ROM monitor prompt
(rommon n>), where n is the number of the command line. Proceed to Step 6.
•
If Break is disabled, power cycle the router (turn the router OFF or unplug the power cord, and then
restore power). Proceed to Step 5.
Step 5
Within 60 seconds of restoring the power to the router, press the Break key or send a Break. This action
causes the router to enter the ROM monitor and display the ROM monitor prompt (rommon 1>).
Step 6
To set the configuration register on a Cisco uBR7100 series router, use the configuration register utility
by entering the confreg command at the ROM monitor prompt as follows:
rommon 1> confreg
Answer yes to the enable “ignore system config info?” question and note the current configuration
register settings.
Step 7
Initialize the router by entering the reset command as follows:
rommon 2> reset
The router will initialize, the configuration register will be set to 0x142, and the router will boot the
system image from Flash memory and enter the System Configuration dialog (setup) as follows:
--- System Configuration Dialog --
Step 8
Enter no in response to the System Configuration dialog prompts until the following message displays:
Press RETURN to get started!
Step 9
Press Return. The user EXEC prompt displays as follows:
Router>
Step 10
Enter the enable command to enter the privileged EXEC mode. Then enter the show startup-config
command to display the passwords in the configuration file as follows:
Router# show startup-config
Step 11
Scan the configuration file display looking for the passwords; the enable passwords are usually near the
beginning of the file, and the console login or user EXEC password is near the end. The passwords
displayed will look something like this:
enable secret 5 $1$ORPP$s9syZt4uKn3SnpuLDrhuei
enable password 23skiddoo
.
.
line con 0
password onramp
The enable secret password is encrypted and cannot be recovered; it must be replaced. The enable and
console passwords can be encrypted or clear text. Proceed to the next step to replace an enable secret,
console login, or enable password. If there is no enable secret password, note the enable and console
login passwords if they are not encrypted and proceed to Step 16.
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Caution
Step 12
Do not perform the next step unless you have determined you must change or replace the enable, enable
secret, or console login passwords. Failure to follow the steps as presented here could cause your router
configuration to be erased.
Enter the configure memory command to load the startup configuration file into running memory. This
action allows you to modify or replace passwords in the configuration.
Router# configure memory
Step 13
Enter the configure terminal command for configuration mode:
Router# configure terminal
Step 14
To change all three passwords, enter the following commands:
Router(config)#
Router(config)#
Router(config)#
Router(config)#
enable secret newpassword1
enable password newpassword2
line con 0
password newpassword3
Change only the passwords necessary for your configuration. You can remove individual passwords by
using the no form of the previous commands. For example, enter the no enable secret command to
remove the enable secret password.
Step 15
You must configure all interfaces to be not administratively shut down as follows:
Router(config)# interface fast ethernet 0/0
Router(config)# no shutdown
Enter the equivalent commands for all interfaces that were originally configured. If you omit this step,
all interfaces are administratively shut down and unavailable when the router is restarted.
Step 16
Use the config-register command to set the configuration register to the original value noted in Step 3
or Step 7.
Step 17
Press Ctrl-z or type end to exit configuration mode:
Router(config)# end
Caution
Step 18
Do not perform the next step unless you have changed or replaced a password. If you have skipped
Step 12 through Step 15 previously, then proceed now to Step 19. Failure to observe this sequence
causes the system to erase your router configuration file.
Enter the copy running-config startup-config command to save the new configuration to nonvolatile
memory:
Router# copy running-config startup-config
Step 19
Enter the reload command to reboot the router:
Router# reload
Step 20
Log in to the router with the new or recovered passwords.
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Configuring the Cisco uBR7100 Series CMTS Using AutoInstall
Configuring the Cisco uBR7100 Series CMTS Using AutoInstall
The AutoInstall process is designed to configure the Cisco uBR7100 series CMTS automatically after
connection to your WAN. For AutoInstall to work properly, a Transmission Control Protocol/Internet
Protocol (TCP/IP) host on your network must be preconfigured to provide the required configuration
files. The TCP/IP host can exist anywhere on the network as long as the following two conditions are
maintained:
•
Host must be on the LAN or WAN side of the router’s port adapter connection to the WAN.
•
User Datagram Protocol (UDP) broadcasts to and from the router and the TCP/IP host are enabled.
This functionality is coordinated by your system administrator at the site where the TCP/IP host is
located. You should not use AutoInstall unless the required files are available on the TCP/IP host. See
the publications Configuration Fundamentals Configuration Guide and Configuration Fundamentals
Command Reference for more information about AutoInstall.
Complete the following steps to prepare your Cisco uBR7100 series CMTS for the AutoInstall process:
Step 1
Attach the appropriate synchronous serial cable to the synchronous serial interface 0 on the router.
Step 2
Turn the power switch on each power supply to the ON (|) position. This action turns on power to the
router.
The router loads the operating system image from Flash memory; this process can take several minutes.
If the remote end of the WAN connection is connected and properly configured, the AutoInstall process
begins.
Step 3
When the AutoInstall process is completed, use the copy running-config startup-config command to
write the configuration data to the router’s nonvolatile random-access memory (NVRAM):
Router# copy running-config startup-config
Completing this step saves the configuration settings that the AutoInstall process created to NVRAM. If
you fail to do this, your configuration will be lost the next time you reload the router.
Configuring Using the setup Facility
The Cisco uBR7100 series setup facility is a useful and efficient tool for configuring your CMTS. The
setup facility supports the following functionalities so that cable interfaces and cable modem cards are
fully operational (after initial setup):
•
Cable-specific commands
•
Upstream frequency definition
For each cable interface, the following information is mandatory:
Per upstream:
cable upstream n frequency f
no cable upstream n shutdown
Options include definition of the following information:
•
DHCP server address.
•
Options are also provided to set downstream frequency for the up-converter per interface.
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If you do not plan to use AutoInstall, do not connect the router’s WAN or LAN cable to the channel
service unit/data service unit (CSU/DSU). If the WAN or LAN cable is connected to the CSU/DSU and
the router does not have a configuration stored in NVRAM, the router attempts to run AutoInstall at
startup.
Tip
The router might take several minutes to determine that AutoInstall is not set up to a remote TCP/IP host.
When the router determines that AutoInstall is not configured, it defaults to the setup facility (also called
the System Configuration dialog). If the LAN or WAN cable is not connected, the router boots from
Flash memory and automatically runs the setup facility.
Note
You can run the setup facility when the enable prompt (#) is displayed by entering the setup command.
Configuring Global Parameters
When you first start the program, configure the global parameters to control system-wide settings:
Step 1
Connect a console terminal to the console port on the I/O controller, and then boot the router.
Step 2
After booting from Flash memory, the following information appears after about 30 seconds. When you
see this information, you have successfully booted your router:
Restricted Rights Legend
Use, duplication, or disclosure by the Government is
subject to restrictions as set forth in subparagraph
(c) of the Commercial Computer Software - Restricted
Rights clause at FAR sec. 52.227-19 and subparagraph
(c) (1) (ii) of the Rights in Technical Data and Computer
Software clause at DFARS sec. 252.227-7013.
Cisco Systems, Inc.
170 West Tasman Drive
San Jose, California 95134-1706
Cisco Internetwork Operating System Software
IOS (tm) uBR7100 Software (uBR7100-I-M), Released Version 12.1(5)EC
Copyright (c) 1986-1998 by Cisco Systems, Inc.
Compiled Mon 09-Oct-98 04:10 by
Cisco 7100 (R4700) processor with 22528K/10240K bytes of memory.
R4700 processor, Implementation 33, Revision 1.0 (Level 2 Cache)
Last reset from power-on
Bridging software.
SuperLAT software copyright 1990 by Meridian Technology Corp).
X.25 software, Version 2.0, NET2, BFE and GOSIP compliant.
TN3270 Emulation software (copyright 1994 by TGV Inc).
4 Ethernet/IEEE 802.3 interfaces.
5 FastEthernet/IEEE 802.3 interfaces.
8 Serial network interfaces.
125K bytes of non-volatile configuration memory.
20480K bytes of Flash PCMCIA card at slot 0 (Sector size 128K).
4096K bytes of Flash internal SIMM (Sector size 256K).
Configuration register is 0x0
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Configuring Using the setup Facility
Note
The first two sections of the configuration script, the banner and the installed hardware, appear
only at initial system startup. On subsequent uses of the setup command facility, the script
begins with the following prompt.
--- System Configuration Dialog ---
At any point you may enter a questions mark ‘?’ for help.
Use ctrl-c to abort configuration dialog at any prompt.
Default settings are in square brackets ‘[]’.
continue with configuration dialog? [yes/no]:
Step 3
When asked if you want to enter the System Configuration dialog and see the current interface summary,
enter yes or press Return:
Continue with configuration dialog? [yes/no]:
First, would you like to see the current interface summary? [yes]:
In the following example, the summary shows a Cisco uBR7100 series router at first-time startup with
nothing configured:
Any interface listed with OK? value "NO" does not have a valid configuration.
Interface
Ethernet1/0
Ethernet1/1
Ethernet1/2
Ethernet1/3
Ethernet1/4
Ethernet1/5
Ethernet1/6
Ethernet1/7
Step 4
IP-Address
9.2.22.3
unassigned
unassigned
unassigned
unassigned
unassigned
unassigned
unassigned
OK
YES
YES
YES
YES
YES
YES
YES
YES
Method
NVRAM
unset
unset
unset
unset
unset
unset
unset
Status
up
administratively
administratively
administratively
administratively
administratively
administratively
administratively
down
down
down
down
down
down
down
Protocol
up
down
down
down
down
down
down
down
Choose which protocols to support on your interfaces. For IP-only installations, you can accept the
default values for most of the questions. A typical configuration using IP follows and continues through
Step 7:
Configuring global parameters:
Enter host name [Router]: router
Step 5
Enter the enable secret password, the enable password, and the virtual terminal password:
The enable secret password is a one-way cryptographic secret
password used instead of the enable password when it exists.
Enter enable secret: ******
The enable password is used when there is no enable secret
password and when using older software and some boot images.
Enter enable password: ******
Enter virtual terminal password: ******
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Step 6
The Simple Network Management Protocol (SNMP) is the most widely supported open standard for
network management. SNMP provides a means to access and set configuration and run-time parameters
of routers and communication servers. SNMP also defines a set of functions that can be used to monitor
and control network elements.
Enter yes to accept SNMP management; enter no to refuse it:
Configure SNMP Network Management? [no]:
Community string [public]:
Step 7
In all cases, you will use IP routing. When you are using IP routing, select an interior routing protocol.
You can specify only one of two interior routing protocols to operate on your system using setup, either
Interior Gateway Routing Protocol (IGRP) or Routing Information Protocol (RIP).
To configure IP routing, enter yes (the default) or press Return, and then select an interior routing
protocol:
Configure IP? [yes]:
Configure IGRP routing? [yes]:
Your IGRP autonomous system number [1]: 15
Step 8
Configure your port adapter interface parameters. The following example shows how an 8-port Ethernet
port adapter is installed in port adapter slot 3. The setup program determines the status of all interfaces.
To configure each active interface port for IP, enter yes (the default) or press Return. For all inactive
ports, the default is no. You can press Return to accept the default.
Configuring interface Ethernet 1/0:
Is this interface in use? [yes]:
Configure IP on this interface? [yes]:
IP address for this interface [19.2.22.4]:
Number of bits in subnet field [8]:
Class A network is 19.0.0.0, 8 subnet bits; mask is /16
Configuring interface Ethernet1/1:
Is this interface in use? [no]:
Configuring interface Ethernet1/2:
Is this interface in use? [no]:
Configuring interface Ethernet1/3:
Is this interface in use? [no]:
Configuring interface Ethernet1/4:
Is this interface in use? [no]:
Configuring interface Ethernet1/5:
Is this interface in use? [no]:
Configuring interface Ethernet1/6:
Is this interface in use? [no]:
Configuring interface Ethernet1/7:
Is this interface in use? [no]:
Step 9
Configure your cable interface. The following example shows a Cisco uBR71111 router with cable
interface. The setup program will, for the most part, determine the status of all interfaces.
To configure each active interface port, enter yes (the default) or press Return. For all inactive ports, the
default is no. You can press Return to accept the default.
Configuring interface cable 1/0:
Is this interface in use? [yes]:
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Configure this interface? [yes]:
IP address for this interface [19.2.22.5]:
Number of bits in subnet field [8]:
Class A network is 19.0.0.0, 8 subnet bits; mask is /16
Configuring interface cable 1/1:
Is this interface in use? [yes]:
Configure this interface? [yes]:
IP address for this interface [19.2.22.6]:
Number of bits in subnet field [8]:
Class A network is 19.0.0.0, 8 subnet bits; mask is /16
The configuration program displays the newly-created command interface script:
The following command script was created:
hostname router
enable secret 5 $1$f0fc$A38P/KN/9yD3sEKSt6hKQ/
enable password betty
line vty 0 4
password wilma
snmp-server community public
!
ip routing
!
interface Ethernet 1/0
ip address 19.2.22.4 255.255.0.0
!
interface Ethernet1/1
shutdown
no ip address
!
interface Ethernet1/2
shutdown
no ip address
!
interface Ethernet1/3
shutdown
no ip address
!
interface Ethernet1/4
shutdown
no ip address
!
interface Ethernet1/5
shutdown
no ip address
!
interface Ethernet1/6
shutdown
no ip address
!
interface Ethernet1/7
shutdown
no ip address
!
interface cable 1/0
ip address 19.2.22.5 255.255.0.0
interface cable 1/1
ip address 19.2.22.6 255.255.0.0
router igrp 15
network 19.0.0.0
!
end
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Step 10
When asked if you want to use this configuration, enter yes or press Return.
Use this configuration? [yes/no]: yes
Step 11
Save your settings to NVRAM. (Refer to the “Using the Setup Facility for Cable Interfaces” section on
page 2-17.)
Note
You must always manually save the configuration settings to NVRAM whenever they are
modified.
Configuring Upstream Frequencies
Upstream parameters must be configured manually. After the setup facility is run, upstream ports have
a default state of “shutdown.” You have two methods to configure upstream channel frequencies:
•
Configure a fixed frequency between 5 to 42 MHz for North American channel plans or
between 5 to 65 MHz for PAL and SECAM channel plans (requires MC16E), and enable the
upstream port.
•
Create a global spectrum group, assign the interface to it, and enable the upstream port.
The cable interface card receiver accepts time-division multiplexed burst transmissions from
cable interfaces (or cable modems in set top boxes) which are DOCSIS- or EuroDOCSIS-based. The
upstream port becomes “up” when it is assigned an upstream frequency and is configured to be
administratively up.
The upstream port is frequency-agile. The frequency can change while the interface is up and carrying
traffic, if you define spectrum groups per the example provided.
You can define individual modulation profiles. A modulation profile consists of a table of physical layer
characteristics for the different types of upstream bursts, for example, initial maintenance, long grant,
request/data, request, short grant, and station maintenance.
Note
Only qualified personnel should define upstream modulation profiles.
Complete these steps to activate upstream interfaces:
Step 1
After the setup facility has initially configured noncable interfaces on the Cisco uBR7100 series router,
enter the enable command and your password (privileged EXEC).
Step 2
Enter the configure terminal command to get into global configuration mode.
Step 3
In global configuration mode, configure modulation profiles and spectrum groups for your Cisco uBR7100
series router using the cable modulation-profile and cable spectrum-group commands.
Step 4
In cable interface configuration mode, configure various characteristics for the interface in question
using the cable upstream commands.
Note
Refer to Chapter 3, “Configuring the Cisco Cable Interface” for further information.
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Configuring Non-Cable Interfaces
Follow the procedure in this section to configure WAN or LAN interfaces. To configure interface
parameters, have your interface network addresses and subnet mask information ready.
Configuring Ethernet Interfaces
Step 1
In the following example, the system is being configured for an Ethernet LAN using IP. Respond to the
prompts as follows, using your own addresses and mask at the setup prompts:
Configuring interface parameters:
Configuring interface Ethernet0/0:
Is this interface in use? [no]: yes
Configure IP on this interface? [no]: yes
IP address for this interface: 1.1.1.10
Number of bits in subnet field [0]:
Class A network is 1.0.0.0, 0 subnet bits; mask is 255.0.0.0
Step 2
Do not enable Internetwork Package Exchange (IPX) on this interface; IPX is not supported on the
Cisco uBR7100 series CMTS:
Configure IPX on this interface? [no]: no
Step 3
If additional Ethernet interfaces are available in your system, enter their configurations when you are
prompted.
Step 4
Save your settings to NVRAM. (See the “Using the Setup Facility for Cable Interfaces” section on
page 2-17.)
Note
You must always manually save the configuration settings to NVRAM whenever they are
modified.
Configuring Synchronous Serial Interfaces
The synchronous serial interfaces are configured to allow connection to WANs through a CSU/DSU.
Complete the following steps to configure the serial ports:
Step 1
To configure serial port 0 enter yes:
Configuring interface Serial0/0:
Is this interface in use? [no]: yes
Step 2
Determine which protocols you want on the synchronous serial interface and enter the appropriate
responses:
Configure IP unnumbered on this interface? [no]:
IP address for this interface: 10.1.1.20
Number of bits in subnet field [0]:
Class A network is 10.0.0.0, 0 subnet bits; mask is 255.0.0.0
Step 3
If additional synchronous serial interfaces are available in your system, enter their configurations when
you are prompted.
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Step 4
Save your settings to NVRAM. (See the “Using the Setup Facility for Cable Interfaces” section on
page 2-17.)
Note
You must always manually save the configuration settings to NVRAM whenever they are
modified.
The following sample display includes a continuous listing of all interface configuration parameters
selected for Ethernet and synchronous serial interfaces. These parameters are shown in the order in
which they appear on your console terminal.
Note
Only one Ethernet and one synchronous serial interface are configured for this example.
Configuring interface parameters:
Configuring interface Ethernet0/0:
Is this interface in use? [no]: yes
Configure IP on this interface? [no]: yes
IP address for this interface: 10.1.1.10
Number of bits in subnet field [0]:
Class A network is 10.0.0.0, 0 subnet bits; mask is 255.0.0.0
Configure IPX on this interface? [no]:
Configure AppleTalk on this interface? [no]: no
Configuring interface Serial0/0:
Is this interface in use? [no]: yes
Configure IP on this interface? [no]: yes
Configure IP unnumbered on this interface? [no]:
IP address for this interface: 10.1.1.20
Number of bits in subnet field [0]:
Class A network is 10.0.0.0, 0 subnet bits; mask is 255.0.0.0
Configure IPX on this interface? [no]:
Configure AppleTalk on this interface? [no]:
The following configuration command script was created:
hostname Router
enable secret 5 $1$u8z3$PMYY8em./8sszhzk78p/Y0
enable password wilma
line vty 0 4
password s
snmp-server community public
!
ip routing
no vines routing
no ipx routing
no appletalk routing
no apollo routing
no decnet routing
no xns routing
no clns routing
no bridge 1
! Turn off IPX to prevent network conflicts.
interface Ethernet0/0
no ipx network
interface Ethernet0/1
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Configuring Using the Configuration Mode
no ipx network
!
interface Ethernet0/0
ip address 1.1.1.10 255.0.0.0
no mop enabled
!
interface serial0/0
ip address 1.1.1.20 255.0.0.0
ip route-cache cbus
no keepalive
!
!
router igrp 15
network 1.0.0.0
!
end
Use this configuration? [yes/no]: yes
[OK]
Use the enabled mode ‘configure’ command to modify this configuration.
Press RETURN to get started!
Your Cisco uBR7100 series CMTS is now minimally configured and is ready to use. You can use the
setup command if you want to modify the parameters after the initial configuration. To perform more
complex configurations, use the configure command.
Configuring Using the Configuration Mode
You can configure the Cisco uBR7100 series CMTS manually if you prefer not to use the setup facility
or AutoInstall. Complete the following:
Step 1
Connect a console terminal to the console port on the I/O controller.
Step 2
When asked if you want to enter the initial dialog, answer no to go into the normal operating mode of
the router:
Would you like to enter the initial dialog? [yes]: no
Step 3
After a few seconds, the user EXEC prompt (Router>) displays. Type enable to enter enable mode
(configuration changes can only be made in enable mode):
Router> enable
The prompt changes to the enable mode (also called privileged EXEC) prompt:
Router#
Step 4
Enter the configure terminal command at the enable prompt to enter configuration mode from the
terminal:
Router# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#
Tip
To see a list of the configuration commands available to you, enter ? at the prompt or type help while in
configuration mode.
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Step 5
At the Router(config)# prompt, enter the interface type slot/port command to enter the interface
configuration mode:
Router(config)# interface cable slot/port
Router(config-if)#
Step 6
Set the downstream center frequency to reflect the digital carrier frequency of the downstream RF carrier
(the channel) for the downstream port:
Router (config-int) # cable downstream frequency down-freq-hz
Note
Step 7
This command has no effect on the external upconverter. It is informational only.
Activate the downstream port on the cable modem card to support digital data transmission over the HFC
network:
Router (config-int) # no shutdown
Step 8
Enter the fixed center frequency for your downstream RF carrier in Hz and the port number:
Router (config-int) # cable upstream port frequency up-freq-hz
Note
Be sure not to select an upstream frequency that interferes with that used for any other upstream
application in your cable plant.
Step 9
Repeat Step 8 for each upstream port on the cable modem card.
Step 10
Activate the upstream port:
Router (config-int) # no cable upstream port shutdown
Step 11
Repeat Step 10 to activate each port used on your cable modem card.
Step 12
Exit to return to the configuration mode:
Router (config-if) # exit
Router (config) #
Step 13
Enter the next interface to configure, following Step 6 through Step 12, or type exit to return to the
enable mode.
Router (config) # exit
Router#
%SYS-5-CONFIG_I: Configured from console by console#
Step 14
Save the configuration to NVRAM:
Router# copy running-config startup-config
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Using the Setup Facility for Cable Interfaces
Using the Setup Facility for Cable Interfaces
The setup facility creates an initial configuration. The basic management setup configures only enough
connectivity for management of the system; the extended setup prompts you to configure each interface
on the system.
To invoke the configuration facility, use the following command:
Router# setup
The following is the system configuration dialog:
Continue with configuration dialog? [yes/no]: yes
Interface Slot Numbering
For Cisco uBR7100 series components, the slot number is the chassis slot in which a port adapter or a
cable interface card is installed. The logical interface number is the physical location of the interface
port on a port adapter.
Numbers on a Cisco uBR7100 series router begin with 0 and are as follows:
•
Slot 0—Fixed Fast Ethernet LAN interface
•
Slot 1—Fixed cable modem card interface
•
Slot 2—Not used
•
Slot 3—Modular single-slot port adapter
•
Slot 4—Not used
•
Slot 5—Not used
Configuring the Interfaces
To configure the system, define the Cisco uBR7100 series interfaces, using the interface type slot/port
command, where:
•
type—Cable, FastEthernet, and installed port adapter.
•
slot—Slot number in chassis. Slot numbers begin with 0.
•
sort—Port number on a cable modem card slot. Port numbers begin with 0.
Configuring the cable interface is particularly important because these components serve as the cable
TV RF interfaces. Configuration involves the following for each interface:
•
Setting the downstream center frequency for the card to reflect the digital carrier frequency of the
downstream RF carrier (the channel) for that downstream port. To do this, enter the fixed center
frequency for your downstream RF carrier in Hz:
Router (config-int) # cable downstream frequency down-freq-hz
Note
Make note of the correct value for the cable modem card. This provides useful information for
troubleshooting.
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The digital carrier frequency is specified to be the center of a 6 or 8 MHz channel based on your
channel plan. For NTSC channel plans, EIA channel 95 spans 90.00 to 96.00 MHz. The center
frequency is 93.000 MHz which is the digital carrier frequency that should be configured as the
downstream frequency.
Tip
The digital carrier frequency is not the same as the video carrier frequency. For EIA channel 95, the
video carrier frequency is 91.250 MHz which is 1.75 MHz below the center frequency.
•
Activating the downstream port on the cable modem card for data transmission over the HFC
network, using the following command:
Router (config-int) # no shutdown
The particular downstream port LED should light.
•
Tip
Setting the upstream frequency of your RF output to comply with the expected input frequency of
your Cisco cable interface.
The valid range for a fixed upstream frequency is 5,000,000 to 65,000,000 Hz for the cable modem card.
The valid range for the Cisco uBR7100 series is 5,000,000 to 42,000,000 Hz.
The cable interface will not operate until you either set a fixed upstream frequency or create and
configure a spectrum group. Enter the fixed center frequency for your upstream RF carrier in Hz and
specify a port number from 0 to 5:
Router (config-int) # cable upstream port frequency up-freq-hz
Note
Ensure that the selected upstream frequency does not interfere with the frequencies used for any
other upstream applications in your cable plant.
•
Enter an upstream RF carrier frequency for each upstream port on a cable modem.
•
Activate the RF carrier on each upstream port to support data from cable modems or set top boxes
on your network to the Cisco uBR7100 series CMTS. Enable upstream data traffic, using the
following command:
Router (config-int) # no cable upstream port shutdown
The specified upstream port LED lights.
Enter the previous command for each upstream port that you wish to activate.
•
Verify your settings using the following command:
Router# show running-config
•
Save the configuration to nonvolatile random access memory (NVRAM) so that your settings are
retained after a power cycle:
Router# copy running start
•
Verify the upstream frequency, using the show controllers cable slot/port upstream command for
the upstream port that you have just configured.
•
Verify the downstream center frequency, using the show controllers cable slot/port downstream
command for the downstream port that you have just configured.
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Identifying the Cable Interface
The Cisco uBR7100 series routers feature a fixed cable interface at slot 1. On the Cisco uBR7111 and
Cisco uBR7111E universal broadband routers, the cable interface supports one downstream modulator
and one upstream demodulator. On the Cisco uBR7114 and Cisco uBR7114E universal broadband
routers, the cable interface supports one downstream modulator and four upstream demodulators.
On all models, the cable interface has the following characteristics:
– The cable interface supports the following defaults: QAM-256 at 40 MBps downstream, and
QAM-16 at 5 Mbps upstream.
– The card supports upstream channel widths of 200 kHz, 400 kHz, 800 kHz, 1.6 MHz, and
3.2 MHz.
– The card outputs +42 dBmV and +/- 2 dBmV.
– The downstream modulator has both an RF output, using the integrated upconverter, and an IF
output, which must be connected to an external upconverter.
Note
The Cisco uBR7111 and Cisco uBR7114 default to transmitting downstream signals to the
integrated upconverter using a 44 MHz frequency. The Cisco uBR7111E and
Cisco uBR7114E default to transmitting downstream IF signals to the integrated
upconverter using the 36.125 MHz frequency.
The cable interface cards can be configured in a number of different upstream combinations based on
the card used, your cable network, and the anticipated subscription and service levels. Table 2-1 shows
the DOCSIS and EuroDOCSIS data rates.
Table 2-1
DOCSIS and EuroDOCSIS Data Rates
Upstream Channel
Width
Modulation
Scheme
Baud Rate
Sym/sec
Raw Bit Rate
Mbit/sec
3.2 MHz
16 QAM
QPSK
2.56 M
10.24
5.12
1.6 MHz
16 QAM
QPSK
1.28 M
5.12
2.56
800 kHz
16 QAM
QPSK
640 K
2.56
1.28
400 kHz
16 QAM
QPSK
320 K
1.28
0.64
200 kHz
16 QAM
QPSK
160 K
0.64
0.32
Cable Interface Card Slots
On Cisco uBR7100 series routers, the cable modem card is fixed and is always slot 1. To display
information about a specific cable interface slot’s downstream channel, use the show interfaces cable
command with the CM card’s slot number and downstream port number in the following format:
show interfaces cable slot/downstream-port [downstream]
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Use the slot number and downstream port number to display information about a downstream interface.
You can abbreviate the command to sh int c. The following example shows the display for upstream
channel port 0 on a Cisco uBR7100 series router.
Router# sh int c 1/0
Cable1/0: Upstream 0 is up
Received 9972 broadcasts, 6096 multicasts, 370221275 unicasts
0 discards, 36137535 errors, 0 unknown protocol
370237908 packets input, 2064921 uncorrectable
29354454 noise, 0 microreflections
Total Modems On This Upstream Channel : 56 (55 active)
Default MAC scheduler
Queue[Rng Polls] 0/64, fifo queuing, 0 drops
Queue[Cont Mslots] 0/53, fifo queuing, 7 drops
Queue[CIR Grants] 0/64, fair queuing, 0 drops
Queue[BE Grants] 1/64, fair queuing, 0 drops
Queue[Grant Shpr]
0/64, calendar queuing, 0 drops
Reserved slot table currently has 0 CBR entries
Req IEs 114588350, Req/Data IEs 0
Init Mtn IEs 241758, Stn Mtn IEs 208872
Long Grant IEs 300445295, Short Grant IEs 1924354
Avg upstream channel utilization : 78%
Avg percent contention slots : 20%
Avg percent initial ranging slots : 1%
Avg percent minislots lost on late MAPs : 0%
Total channel bw reserved 0 bps
CIR admission control not enforced
Admission requests rejected 0
Current minislot count
: 9461304
Flag: 0
Scheduled minislot count : 9462255
Flag: 0
To display information about a specific cable interface slot’s upstream channel, use the
show interfaces cable command. Include these CM card parameters:
•
slot number
•
downstream port number
•
upstream port number
Use this format:
show interfaces cable slot/downstream-port [upstream] upstream-port
Use the slot number, downstream port number, and upstream port number to display information about
an upstream interface. You can abbreviate the command to sh int c.
The following example shows the display for upstream channel port 0 in cable interface slot 3 of a
Cisco uBR7100 series router that is turned up:
Router# sh int c 1/0 0
Cable1/0: Upstream 0 is up
Received 3699 broadcasts, 0 multicasts, 28586 unicasts
0 discards, 0 errors, 0 unknown protocol
21817 packets error-free, 2371 corrected, 8097 uncorrectable
0 noise, 0 microreflections
CBR_queue_depth: [not implemented], ABR_queue_depth: [not implemented],
UBR[1]_queue_depth: 0, UBR[2]_queue_depth: 0,
UBR[3]_queue_depth: 0, POLLS_queue_depth: [not implemented]
ADMIN_queue_depth: [not implemented]
Last Minislot Stamp (current_time_base):190026
FLAG:1
Last Minislot Stamp (scheduler_time_base):200706 FLAG:1
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Mapping Interfaces and Physical Ports
Table 2-2 maps the cable interface card’s interfaces and physical ports. The cards can be configured in
a number of different upstream combinations.
Table 2-2
Interface to Port Mapping
Cisco uBR7100 Series
Cable Interface
Physical Ports
Cisco uBR7111
Cable 1/0
DS RF, DS IF, US0
Cisco uBR7111E
Cable 1/0
DS RF, DS IF, US0
Cisco uBR7114
Cable 1/0
DS RF, DS IF, US0, US1, US2, US3
Cisco uBR7114E
Cable 1/0
DS RF, DS IF, US0, US1, US2, US3
Identifying Port Adapter Slots
On the Cisco uBR7100 series universal broadband routers, two port adapter slots are available. Slot 0 is
the fixed FastEthernet interface, and slot 3 is the modular port adapter. You can display information on
a specific port adapter or all port adapters in the Cisco uBR7100 series router. To display information
about all port adapter slots, use the show interfaces command. To display information about a specific
port adapter slot, use the show interfaces command with the port adapter type and slot number in the
format of show interfaces [type slot/port].
Tip
If you abbreviate the command (sh int) and do not specify the port adapter type and slot number (or
arguments), the system interprets the command as show interfaces. The system displays the status of all
port adapters, all cable interface cards, and all ports.
Following is an example of how the show interfaces command displays status information (including
the physical port adapter number) for each port adapter and cable interface card in the Cisco uBR7111:
FastEthernet0/0 is up, line protocol is up
Hardware is DEC21140A, address is 0002.b9ff.7c00 (bia 0002.b9ff.7c00)
Internet address is 1.7.35.1/16
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive not set
Full-duplex, 100Mb/s, 100BaseTX/FX
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:01, output 00:00:04, output hang never
(statistical information omitted)
FastEthernet0/1 is administratively down, line protocol is down
Hardware is DEC21140A, address is 0002.b9ff.7c01 (bia 0002.b9ff.7c01)
Internet address is 1.1.1.2/24
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
reliability 252/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 100Mb/s, 100BaseTX/FX
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output 23:55:58, output hang never
(statistical information omitted)
Cable1/0 is up, line protocol is up
Hardware is BCM3210 ASIC, address is 0002.b9ff.7c1c (bia 0002.b9ff.7c1c)
Internet address is 2.35.1.1/16
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MTU 1500 bytes, BW 27000 Kbit, DLY 1000 usec,
reliability 255/255, txload 19/255, rxload 24/255
Encapsulation MCNS, loopback not set
Keepalive not set
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:02, output 00:00:00, output hang never
(statistical information omitted)
Interface Cable1/0
Hardware is IMC11
BCM3210 revision=0x56B2
Upconverter info: Config status 0x4E, Dynamic Status 0x0
Upconverter output is Enabled
IF ALC is Enabled, Threshold capability is Enabled
RF ALC is Enabled, Threshold capability is Enabled
Downstream Frequency 669.0000 MHz
(statistical information omitted)
Cable1/0 Downstream is up
Frequency 669.0000 MHz, Channel Width 6 MHz, 256-QAM, Symbol Rate 5.360537 Msps
FEC ITU-T J.83 Annex B, R/S Interleave I=32, J=4
Downstream channel ID: 0
Cable1/0 Upstream 0 is up
Frequency 38.000 MHz, Channel Width 3.200 MHz, 16-QAM Symbol Rate 2.560 Msps
Spectrum Group is overridden
SNR 30.8820 dB
(statistical information omitted)
FastEthernet1/0 is up, line protocol is up
Hardware is DEC21140A, address is 0002.b9ff.7c28 (bia 0002.b9ff.7c28)
Internet address is 192.100.68.100/24
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive not set
Full-duplex, 100Mb/s, 100BaseTX/FX
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:01, output 00:00:01, output hang never
(statistical information omitted)
You can also use arguments such as the interface type (Ethernet, Fast Ethernet, ATM, serial, HSSI,
Packet-over-SONET, and so forth) and the port address (slot/port) to display information about a specific
port adapter interface only. The following example shows such a display:
R7732-01-uBR7111_Router# sh int f0/0
FastEthernet 1/0 is up, line protocol is up
Hardware is AmdFE, address is 0030.7bfa.a81c (bia 0030.7bfa.a81c)
Internet address is 111.0.1.18/30
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 100Mb/s, 100BaseTX/FX
ARP type:ARPA, ARP Timeout 04:00:00
Last input 00:00:01, output 00:00:02, output hang never
Last clearing of "show interface" counters never
Queuing strategy:fifo
Output queue 0/40, 0 drops; input queue 0/75, 0 drops
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
0 packets put, 230925 bytes
Received 146107 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog
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0 input packets with dribble condition detected
0 packets put, 284529 bytes, 0 underruns
0 output errors, 0 collisions, 10 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
Note
The interface type in the show interfaces command must match the actual interface type of the port
adapter. For example, if you enter sh int e 1/0 and a HSSI port adapter is actually in port adapter slot
1/0, the command returns an “invalid input” error.
Tip
At any time you can enter a question mark (?) for help. Use ctrl-c to abort the configuration dialog at
any prompt. The default settings are enclosed in brackets '[]'.
Would you like to enter basic management setup? [yes/no]: no
First, would you like to see the current interface summary? [yes]:
Interface
IP-Address
OK? Method Status
FastEthernet0/0
10.20.133.2
YES NVRAM up
up
FastEthernet1/0
1.11.1.1
YES NVRAM up
Cable1/0
10.20.133.65
YES NVRAM up
Protocol
up
up
Configuring Global Parameters
Step 1
Type this command: Enter host name [ishita-cmts]:
Next, the enable secret is a password used to protect access to privileged EXEC and configuration
modes. This password, after entered, becomes encrypted in the configuration.
Step 2
Type this command: Enter enable secret [Use current secret]: aa
Next, the enable password is used when you do not specify an enable secret password, with some older
software versions, and some boot images.
Step 3
Type this command: Enter enable password [rHoz]: bb
Next, the virtual terminal password is used to protect access to the router over a network interface.
Step 4
Type this command: Enter virtual terminal password [cc]:cc
The following system information displays.
Configure SNMP Network Management? [no]:
Configure IP? [yes]:
Configure IGRP routing? [yes]:
Your IGRP autonomous system number [1]:
Configure CLNS? [no]:
Configuring interface parameters:
Do you want to configure FastEthernet0/0 interface? [yes]:
Use the 100 Base-TX (RJ-45) connector? [yes]:
Operate in full-duplex mode? [no]:
Configure IP on this interface? [yes]: no
Do you want to configure Ethernet1/0 interface? [yes]: n
Do you want to configure Cable1/0 interface? [yes]:
Downstream setting frequency : 531000000
For cable upstream [0]
Shut down this upstream ? [yes/no]: no
Frequency : 33808000
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Would you like to configure the DHCP server ? [yes/no]: yes
IP address for the DHCP server
[X.X.X.X]: 10.0.0.2
Configure IP on this interface? [no]: yes
IP address for this interface: 10.20.133.65
Subnet mask for this interface [255.0.0.0] : 255.255.255.248
Class A network is 10.0.0.0, 29 subnet bits; mask is /29
The following configuration command script is created:
interface Cable1/0
ip address 10.20.133.65 255.255.255.248
no ip mroute-cache
no keepalive
cable insertion-interval 500
cable downstream annex B
cable downstream modulation 64qam
cable downstream interleave-depth 32
cable downstream frequency 531000000
cable upstream 0 frequency 33808000
cable upstream 0 power-level 0
no cable upstream 0 shutdown
cable helper-address 10.0.0.2
Note
For modems to acquire an IP address, they must have direct access to DHCP, TFTP, or TOD servers, or
have a static route set.
Saving Your Configuration Settings
To store the configuration or changes to your startup configuration in NVRAM, enter the
copy running-config startup-config command at the Router# prompt:
Router# copy running-config startup-config
This command saves the configuration settings you set using configuration mode, the setup facility, or
AutoInstall.
Tip
If you do not save your settings, your configuration will be lost the next time you reload the router.
Checking Your Settings and Reviewing Your Configuration
Changes
You can check your settings and review any changes to your configuration using various software
commands.
To view information specific to the hardware and cable interface configuration on your Cisco uBR7100
series CMTS, use show commands.
To verify the downstream center frequency:
Router# show controllers cable slot/port downstream
To verify the current value of an upstream port frequency:
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Router# show controllers cable slot/port upstream
To check the value of the settings you entered, enter the show running-config command at the Router#
prompt:
Router# show running-config
To review changes you make to the configuration, use the EXEC show startup-config command to
display the information stored in NVRAM.
Where to Go Next
After you have minimally configured the Cisco uBR7100 series CMTS, refer to Chapter 3, “Configuring
the Cisco Cable Interface” for more advanced configuration instructions. Also refer to Chapter 5,
“Troubleshooting the System” for information on troubleshooting your initial configuration.
The Cisco IOS software running the Cisco uBR7100 series CMTS contains extensive features and
functionality. The effective use of these features is easier if you have more information at hand. For
additional documentation about configuring the Cisco uBR7100 series CMTS and system capabilities,
refer to resources cited in the “Preface”. For instructions on configuration of port adapters, refer to the
respective installation document that shipped with the port adapter.
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3
Configuring the Cisco Cable Interface
The Cisco IOS software command-line interface (CLI) can be used to configure the Cisco cable modem
interface for correct operation on the hybrid fiber coax cable (HFC) network. This chapter describes the
following tasks required to configure the Cisco cable modem card.
Note
For tasks marked optional below, default settings are typically adequate to configure the system. Change
default settings only with careful prior analysis.
•
“Configuring the Downstream Cable Interface” section on page 3-1
•
“Configuring the Upstream Cable Interface” section on page 3-9
•
“Enabling and Configuring Baseline Privacy” section on page 3-23 (Optional)
•
“Configuring and Activating Frequency Agility” section on page 3-28
•
“Activating Cable Address Resolution Protocol Requests” section on page 3-35
•
“Activating Host-to-Host Communication (Proxy ARP)” section on page 3-36 (Optional)
•
“Configuring DHCP Options” section on page 3-37
•
“Configuring Time-of-Day Service” section on page 3-38
•
“Setting Optional IP Parameters” section on page 3-38 (Optional)
•
“Activating Packet Intercept Capabilities” section on page 3-40 (Optional)
•
“Configuring Cable Modulation Profiles” section on page 3-41
•
“Setting Quality of Service (QoS) for Higher Priority Traffic” section on page 3-46
•
“Setting and Viewing Concatenation” section on page 3-52 (Optional)
Configuring the Downstream Cable Interface
The first step in configuring the Cisco CM interface is to configure the downstream cable interface,
which generally entails the downstream frequency, symbol rate, compression, and modulation.
Configuring the downstream cable interface consists of the following specific tasks:
•
“Activating the Downstream Carrier” section on page 3-2
•
“Setting the Integrated Upconverter” section on page 3-3
•
“Setting the Downstream Channel ID” section on page 3-4
•
“Setting the MPEG Framing Format” section on page 3-5
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Note
•
“Setting the Downstream Modulation” section on page 3-6
•
“Setting the Downstream Interleave Depth” section on page 3-6
•
“Setting the Downstream Helper Address” section on page 3-7
•
“Setting Downstream Rate Limiting” section on page 3-8
In most applications, default values for the commands used in these configuration steps are adequate to
configure the Cisco uBR7100 series router. You do not need to specify individual parameters unless you
want to deviate from system defaults.
For information on other configuration options, see the “Cisco Cable Modem Termination System
Commands” chapter in the Broadband Command Consolidation Guide, available on Cisco.com and the
Documentation CD-ROM.
Activating the Downstream Carrier
To activate a downstream port on a Cisco uBR7100 series cable interface card for digital data
transmissions over the HFC network, complete the steps in the following table.
Step 1
Step 2
Step 3
Command
Purpose
CMTS01> enable
Enter enable (privileged EXEC) mode.
Password: password
Enter the password.
CMTS01#
You have entered privileged EXEC mode when the
prompt displays the pound symbol (#).
CMTS01# configure terminal
Enter configuration commands, one per line. End with
CNTL/Z.
Enter global configuration mode. You have entered
global configuration mode when the prompt displays
(config)#.
CMTS01(config)#
This command can be abbreviated to config t.
CMTS01(config)#
interface cable1/0
CMTS01(config-if)#
Step 4
Enter cable interface configuration mode.
In this example, the interface is downstream port 0 on
the cable interface card installed in slot 1 of the
Cisco uBR7100 series CMTS.
CMTS01(config-if)#
cable downstream if-output
Default. Activate downstream digital data from the
Cisco uBR7100 series router.
CMTS01(config-if)#
no cable downstream if-output
Deactivate downstream digital data. This command
mutes the IF output of the cable interface card and
shuts down the interfaces.
Step 5
CMTS01(config-if)#
no shutdown
Place the downstream port in the “admin up” state.
Step 6
CMTS01(config-if)# end
Return to privileged EXEC mode.
CMTS01#
%SYS-5-CONFIG_I: Configured from console by console
This message is normal and does not indicate an error.
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Configuring the Downstream Cable Interface
Verifying the Downstream Carrier
To determine if the downstream carrier is active (up), enter the show controllers cable command for the
downstream port that you just configured. For NTSC 6 MHz operations, see the following example:
CMTS01# show controllers cable1/0 downstream
Cable1/0 Downstream is up
Frequency=96000000, Channel Width 6 MHz, 64-QAM, Symbol Rate 5.056941 Msps
FEC ITU-T J.83 Annex B, R/S Interleave I=32, J=4
Setting the Integrated Upconverter
The Cisco uBR7100 series router supports an integrated upconverter that outputs a DOCSIS RF signal
on the DS0 RF downstream port. To enable the integrated upconverter, you must do the following:
•
Note
Set the downstream frequency—The integrated upconverter must be configured for the digital
carrier frequency, which is the center frequency of the downstream RF carrier (the channel) for the
downstream port. The cable downstream frequency command configures the downstream center
frequency for the integrated upconverter.
The cable downstream frequency command has no effect on external upconverters. If you are using an
external upconverter, this command is informational only and you must configure the external
upconverter separately, using its own command procedures.
•
Enable the integrated upconverter—The integrated upconverter is disabled by default and must be
enabled with the no cable downstream rf-shutdown command.
•
Enable the cable interface—The cable interface on the Cisco uBR7100 series router must be enabled
before the integrated upconverter will output an RF signal.
To configure the integrated upconverter, use the following commands in cable interface configuration
mode.
Command
Purpose
ubr7100(config)# interface cable 1/0
Enter interface configuration mode for the cable
interface on the Cisco uBR7100 series router.
ubr7100(config-if)# cable downstream
frequency down-freq-hz
Enter the fixed center frequency for your
downstream RF carrier in Hz. Allowable DOCSIS
center frequencies are 91,000,000 to 857,000,000
Hz (the default is 500,000,000 Hz).
ubr7100(config-if)# no cable downstream
rf-shutdown
Enable the integrated upconverter.
ubr7100(config-if)# no shutdown
Enable the cable interface.
Verifying the Integrated Upconverter Configuration
To verify the configuration for the integrated upconverter, enter the show controllers cable downstream
command. The following is a typical display with a correctly configured center frequency:
router# show controllers cable1/0 downstream
Cable1/0 Downstream is up
Frequency=525000000, Channel Width 6 MHz, 64-QAM, Symbol Rate 5.056941 Msps
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Configuring the Downstream Cable Interface
FEC ITU-T J.83 Annex B, R/S Interleave I=32, J=4
Downstream channel ID: 0
Then enter the show controllers cable command, which also displays the center frequency, along with
the power levels and whether the integrated upconverter is enabled. The following is a typical display
when these values have been correctly configured:
ubr7100# show controllers cable1/0
Interface Cable1/0
Hardware is IMC11
BCM3210 revision=0x56B2
Cable1/0 Upconverter is Enabled Output is Enabled
Model: 74-2094-01 Serial Number: 0WAV04480010 CLEI Code:
CLEI#
HW Rev:
PC2D0107 SW Rev: 007, NVRAM Rev: 006 ECI number 123456
Downstream Frequency 525.0000 MHz
IF Power 0.3 dBmv RF Power 51.0 dBmv
...
If the center frequency has not been configured, the frequency is shown as “not set” as shown in the
following example:
ubr7100# show controllers cable1/0 downstream
Cable1/0 Downstream is up
Frequency is not set. Channel Width 6 MHz, 64-QAM, Symbol Rate 5.056941 Msps
FEC ITU-T J.83 Annex B, R/S Interleave I=32, J=4
Downstream channel ID: 0
If you are having trouble, make sure the cable connections are not loose or disconnected, and that you
have calculated and entered the center frequency for your router accurately.
Setting the Downstream Channel ID
To assign a numeric channel ID to the downstream port on the Cisco cable modem card, use the following
command in cable interface configuration mode. Acceptable range is 0 to 255.
CMTS01(config-if)# cable downstream channel-id id
Note
The cable downstream channel-id command must be used with the following command:
cable downstream frequency 54000000-1000000000 broadcast frequency - h
The commands are used in instances where you want to send multiple downstream frequencies to a
single region that contains CMs that can only connect to upstream ports on the same cable modem card.
You must configure unique channel IDs for each downstream that any CM is capable of receiving. The
downstream frequency setting must match the setting on the upconverter.
Caution
After defining unique downstream IDs, test the CMs for correct operation. Cisco recommends when
using this feature that you re-test each subsequent software release of CM code to verify correct
operation, and ensure reasonable acquisition time for new installations. Failure to use these commands
in conjunction or to test the involved CMs can result in customer service outages of indefinite duration.
Verifying the Downstream Channel ID
To verify the downstream channel ID, enter the show controllers cable command for the downstream
port you have just configured. See the following example:
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Router# show controllers cable1/0 downstream
Cable1/0 Downstream is up
Frequency=96000000, Channel Width 6 MHz, 64-QAM, Symbol Rate 5.056941 Msps
FEC ITU-T J.83 Annex B, R/S Interleave I=32, J=4
Downstream channel ID: 1
For EuroDOCSIS operations, a sample appears below:
Router# show controllers cable 1/0 downstream
Cable1/0 Downstream is up
Frequency 669.0000MHz, Channel Width 8MHz, 64-QAM, Symbol Rate
6.952000 Msps
FEC ITU-T J.83 Annex A, R/S Interleave I=12, J=17
Downstream channel ID: 1
Setting the MPEG Framing Format
The MPEG framing format must be compatible with DOCSIS or EuroDOCSIS specifications and your
local cable plant operations.
Tip
Annex B is the DOCSIS MPEG framing format standard for North America, supported on the
Cisco uBR7111 and Cisco uBR7114 routers. Annex A is the European standard, supported on the
Cisco uBR7111E and Cisco uBR7114E routers.
Note
Annex A or B framing format is automatically set when configuring the cable interface. The downstream
ports and the connected CMs on the network must be set to the same MPEG framing format and support
DOCSIS or EuroDOCSIS operations as appropriate.
The following command appears in the Cisco uBR7100 series router configuration file to designate
Annex B or Annex A operation. This command sets the downstream MPEG framing format.
CMTS01(config-if)# cable downstream annex
{ B}
Verifying the Downstream MPEG Framing Format
To verify the downstream MPEG framing format setting, enter the show controllers cable command for
the downstream port you have just configured. See the following example:
router# show controllers cable1/0 downstream
Cable1/0 Downstream is up
Frequency=96000000, Channel Width 6 MHz, 64-QAM, Symbol Rate 5.056941 Msps
FEC ITU-T J.83 Annex B, R/S Interleave I=32, J=4
Downstream channel ID: 0
A sample output appears below for EuroDOCSIS operations:
Router# show controllers cable 1/0 downstream
Cable3/0 Downstream is up
Frequency 669.0000MHz, Channel Width 8MHz, 64-QAM, Symbol Rate
6.952000 Msps
FEC ITU-T J.83 Annex A, R/S Interleave I=12, J=17
Downstream channel ID: 0
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Setting the Downstream Modulation
To set the downstream modulation, define the speed in symbols per second at which data travels
downstream to the subscriber’s CM. A symbol is the basic unit of modulation. QPSK encodes 2 bits per
symbol, QAM-16 encodes 4 bits per symbol, QAM-64 encodes 6 bits per symbol, and QAM-256
encodes 8 bits per symbol.
Note
Setting a downstream modulation rate of QAM-256 requires approximately a 6 dB higher
signal-to-noise ratio (SNR) than QAM-64 at the subscriber’s cable interface. If your network is marginal
or unreliable at QAM-256, use the QAM-64 format instead. Also, consider the significance of your data.
Use the following command in cable interface configuration mode to set the downstream modulation.
The standard DOCSIS modulation rate (and the Cisco default) is QAM-64.
CMTS01(config-if)# cable downstream modulation 64qam
Verifying the Downstream Modulation
To verify the downstream modulation setting, enter the show controllers cable command for the
downstream port you have just configured. See the following example:
Router# show controllers cable1/0 downstream
Cable1/0 Downstream is up
Frequency=96000000, Channel Width 6 MHz, 64-QAM, Symbol Rate 5.056941 Msps
FEC ITU-T J.83 Annex B, R/S Interleave I=32, J=4
Perform these steps if you are having difficulty with verification:
1.
Ensure the cable connections are not loose or disconnected.
2.
Ensure the cable modem card is firmly seated in its chassis slot.
3.
Ensure the captive installation screws are tight.
4.
Verify that you have entered the correct slot and port numbers
5.
Verify the downstream carrier is active using the cable downstream if-output command
6.
Verify that you have selected the default if you are not certain about the modulation rate needed.
Setting the Downstream Interleave Depth
Set the interleave depth for the downstream port on the Cisco cable modem card. A higher interleave
depth provides more protection from bursts of noise on the HFC network; however, it will increase
downstream latency.
Note
The valid values are 8, 16, 32 (default), 64, and 128.
To set the downstream interleave depth in milliseconds, use the following command in cable interface
configuration mode:
CMTS01(config-if)# cable downstream interleave-depth {8|16|32 |64|128}
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Verifying the Downstream Interleave Depth
To verify the downstream interleave depth setting, enter the show controllers cable command for the
downstream port you have just configured:
Router# show controllers cable1/0 downstream
Cable1/0 Downstream is up
Frequency=96000000, Channel Width 6 MHz, 64-QAM, Symbol Rate 5.056941 Msps
FEC ITU-T J.83 Annex B, R/S Interleave I=32, J=4
Perform these steps if you are having difficulty with verification:
1.
Ensure the cable connections are not loose or disconnected.
2.
Ensure the cable modem card is firmly seated in its chassis slot.
3.
Ensure the captive installation screws are tight.
4.
Verify that you have entered the correct slot and port numbers.
5.
Verify that the downstream carrier is active using the cable downstream if-output command.
Setting the Downstream Helper Address
Specify an IP address of a DHCP server where UDP broadcast (DHCP) packets will be sent. You can
specify a DHCP server for UDP broadcast packets from cable interfaces, and a DHCP server for UDP
broadcast packets from hosts.
To set a downstream helper address, use the following commands in cable interface configuration mode.
Step 1
Command
Purpose
cable
helper-address 10.x.x.x cable-modem
Set the downstream helper address to the DHCP server at IP address
10.x.x.x for UDP broadcast packets from cable modems.
CMTS01(config-if)#
Note
Step 2
cable
helper-address 172.56.x.x host
CMTS01(config-if)#
Use the IP address of the DHCP server. Both 10.x.x.x and
172.56.x.x are private ranges.
Set the downstream helper address to the DHCP server at IP address
172.56.x.x for UDP broadcast packets from hosts.
Verifying the Downstream Helper Address
To verify the downstream helper address setting, enter the show running-config command and look for
cable helper-address in the cable interface configuration information:
CMTS01# show running-config
Building configuration...
Current configuration:
!
interface Cable1/0
ip address 10.254.254.254 255.0.0.0
no ip directed-broadcast
cable helper-address 192.168.1.1
no keepalive
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Perform these steps if you are having difficulty with verification:
1.
Check the cables, upconverters, RF levels, and frequencies if the cable interfaces do not find a
downstream signal.
2.
Check the cables, RF levels, and upstream frequencies, and enter a no shut command if the
cable interfaces find a downstream signal, but not an upstream signal.
3.
Check the provisioning servers, ping the DHCP server using the source IP address option—the
primary IP address of a cable interface, check IP routing if the cable interfaces acquire an RF
upstream and downstream lock, but do not stay up.
4.
Check DHCP options and the IP address of the TOD server, ping the TOD server using the source
IP address option, check IP routing, verify that the TFTP filename is correct, verify the TFTP file is
in the correct directory on the TFTP server, ensure the TFTP file has read privileges, ping the TFTP
server using the source IP address option, and check IP routing if the cable interfaces acquire an RF
and a DHCP, but fail on TOD or TFTP.
Setting Downstream Rate Limiting
Downstream rate limiting enables you to use the token bucket policing algorithm with traffic shaping
options or the weighted discard policing algorithm to buffer, shape, or discard packets that exceed a set
bandwidth. Downstream rate limiting is disabled by default.
To enable downstream rate limiting for a downstream port on a Cisco cable modem card, use one of the
following commands in cable interface configuration mode.
Command
Purpose
CMTS01(config-if)#
cable downstream
rate-limit token-bucket
Enable rate limiting on the downstream port using the
token bucket policing algorithm. With this command,
the Cisco uBR7100 series router automatically drops
packets that are in violation of the allowable bandwidth.
cable downstream
rate-limit token-bucket shaping
Enable rate limiting on the downstream port using the
token bucket policing algorithm with traffic shaping.
CMTS01(config-if)#
cable downstream
rate-limit token-bucket shaping
granularity 8
CMTS01(config-if)#
Enable rate limiting on the downstream port using the
token bucket policing algorithm with specific traffic
shaping time granularity. Acceptable values are 1, 2, 4,
8, or 16 milliseconds.
cable downstream
rate-limit token-bucket shaping max-delay Enable rate limiting on the downstream port using the
256
token bucket policing algorithm with specific maximum
traffic shaping buffering delay. Acceptable values are
128, 256, 512, or 1028 milliseconds.
CMTS01(config-if)#
CMTS01(config-if)#
cable downstream
rate-limit weighted-discard 3
Enable rate limiting on the downstream port using the
weighted packet discard policing algorithm and assign a
weight for exponential moving average of loss rate.
Acceptable values are 1 to 4.
CMTS01(config-if)# ^Z
CMTS01#
Exit back to EXEC mode so that you can verify the
steps.
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Verifying Downstream Rate Limiting
To determine if downstream rate limiting is configured and activated, enter the show running-config
command and look for the cable interface configuration information. If downstream rate limiting is
configured and enabled, a rate limiting entry displays in the output. If downstream rate limiting is
disabled, no rate limiting entry displays.
CMTS01# show running-config
Building configuration...
Current configuration:
!
interface Cable1/0
ip address 10.254.254.254 255.0.0.0
no ip directed-broadcast
cable helper-address 192.168.1.1
no keepalive
cable downstream rate-limit token-bucket shaping
cable downstream annex B
cable downstream modulation 64qam
Perform these steps if you are having difficulty with verification:
1.
Ensure the cable connections are not loose or disconnected.
2.
Ensure the cable modem card is firmly seated in its chassis slot.
3.
Ensure the captive installation screws are tight.
4.
Verify that you have entered the correct slot and port numbers
5.
Verify that you selected the default if you are not certain about the modulation rate needed.
6.
Verify the downstream carrier is active using the cable downstream if-output command.
Configuring the Upstream Cable Interface
Upstream cable interface commands configure the frequency and input power level of the upstream
signal, in addition to error detection and correction of the upstream signal. The configuration of the
upstream cable interface depends on the characteristics of your cable plant.
Perform the following tasks to configure the upstream cable interface.
Note
For some of these tasks, default values are adequate to configure the device.
•
“Setting the Upstream Frequency” section on page 3-10
•
“Setting the Upstream Channel Width” section on page 3-11
•
“Setting the Upstream Input Power Level” section on page 3-13
•
“Activating Upstream Admission Control” section on page 3-14
•
“Activating Upstream Forward Error Correction (FEC)” section on page 3-14
•
“Specifying Upstream Minislot Size” section on page 3-15
•
“Activating the Upstream Scrambler” section on page 3-16
•
“Activating Upstream Differential Encoding” section on page 3-16
•
“Activating Upstream Rate Limiting” section on page 3-17
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•
“Activating Upstream Frequency Adjustment” section on page 3-18
•
“Activating Upstream Power Adjustment” section on page 3-19
•
“Activating Upstream Timing Adjustment” section on page 3-20
•
“Activating the Upstream Ports” section on page 3-20
•
“Setting Upstream Backoff Values” section on page 3-21
Setting the Upstream Frequency
The upstream channel frequency of your RF output must be set to comply with the expected input
frequency of your Cisco cable modem card. To configure upstream channel frequencies, perform one of
the following tasks:
•
Configure a fixed frequency between 5 to 42 MHz for NTSC operations, then enable the upstream
port.
•
Create a global spectrum group, assign the interface to it, and enable the upstream port.
Note
You can also select a default that does not set a specific fixed value.
Note
The upstream port is frequency-agile. If you define spectrum groups, the frequency can change while the
interface is up and carrying traffic.
A modulation profile consists of a table of physical layer characteristics for the different types of
upstream bursts; for example, initial maintenance, long grant, request/data, request, short grant, and
station maintenance.
Note
The upstream cable interface does not operate until you either set a fixed upstream frequency or create
and configure a spectrum group.
If you are setting a fixed upstream frequency, make sure that the frequency selected does not interfere
with the frequencies used for any other upstream applications running on the cable plant.
To set a fixed upstream frequency, use the following commands in cable interface configuration mode.
Tip
Command
Purpose
CMTS01(config-if)# cable upstream usport
frequency up-freq-hz
Enter the fixed center frequency for your upstream
RF carrier in Hz.
CMTS01(config-if)# no cable upstream
usport shutdown
Place the upstream port in the “admin up” state.
For NTSC operations, valid ranges are 5000000 to 42000000 Hz.
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Caution
Some cable systems cannot reliably transport frequencies near these band edges. The wider the upstream
channel (in MHz), the more difficulty you might have. Enter a center frequency between 20 and 38 MHz
if you have difficulty.
Note
You can also select a default that does not set a specific fixed value. The Cisco uBR7100 series software
commands the cable interfaces to use this frequency as the center frequency.
Verifying the Upstream Frequency
To verify the current value of the upstream frequency, enter the show controllers cable command for
the upstream port you have just configured:
CMTS01# show controllers cable1/0 u0
Cable1/0 Upstream 0 is up
Frequency 24.016 MHz, Channel Width 1.600 MHz, QPSK Symbol Rate 1.280 Msps
Spectrum Group is overridden
SNR 33.2560 dB
Nominal Input Power Level 0 dBmV, Tx Timing Offset 2288
Ranging Backoff automatic (Start 0, End 3)
Ranging Insertion Interval automatic (60 ms)
Tx Backoff Start 0, Tx Backoff End 4
Modulation Profile Group 1
Note
The upstream frequency displayed in the show controllers cable command output might not match the
frequency that you entered when you set the upstream frequency. The Cisco uBR7100 series CMTS
might select an upstream frequency close to the frequency you entered that offers better performance.
The Cisco uBR7100 series CMTS selects the closest frequency available.
Perform these steps if you are having difficulty with verification:
1.
Ensure the cable connections are not loose or disconnected
2.
Ensure the cable modem card is firmly seated in its chassis slot.
3.
Ensure the captive installation screws are tight.
4.
Verify that you have entered the correct slot and port numbers.
5.
Verify that you have selected a valid frequency for your router.
Setting the Upstream Channel Width
Enter the channel width in hertz (Hz). For NTSC operations, valid values are 200000 Hz
(160 kilosymbols per second [ksps]), 400000 Hz (320 ksps), 800000 Hz (640 ksps), 1600000 Hz
(1280 ksps), and 3200000 Hz (2560 ksps). The default is 1600000 Hz.
If no acceptable channels of the specified width are found, the spectrum management card automatically
begins to scan the upstream spectrum for the next largest available channel width; for example, if the
spectrum management card is unable to find a usable 1.6 MHz upstream channel, it automatically begins
searching for usable 800 kHz channels.
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Caution
Higher symbol rates are more susceptible to RF noise and interference. If you use a symbol rate or
modulation format beyond the capabilities of your HFC network, you might experience packet loss or
loss of cable interface connectivity.
Note
For QAM-16 channel widths of 400 kHz (320 ksps) or greater, Cisco recommends that you use QAM-16
modulation for long and short data, and that you use QPSK for request, initial, and station
communications. For QAM-16 channel widths of 200 kHz (160 ksps), all communication must be able
to use QAM-16. That is, 160 ksps with QAM-16 requires an exceptional signal-to-noise ratio (SNR) in
your upstream channel(s). When you use QAM-16 for request, initial, and station maintenance messages
with channel widths greater than 400 kHz, the QAM-16 preamble and message data take longer to
transmit than the QPSK format.
Note
To set the upstream channel width, use the following commands in cable interface configuration mode.
Command
Purpose
CMTS01(config-if)# cable upstream
usport channel-width width
Enter the channel width for your upstream RF carrier
in Hz.
CMTS01(config-if)# no cable upstream
usport channel-width
Return the channel width to its default setting of
1600000 Hz.
Verifying Upstream Channel Width
To verify the current value of the upstream channel width, enter the show controllers cable command
for the upstream port you just configured. A sample appears below:
CMTS01# show controllers cable1/0 u0
Cable1/0 Upstream 0 is up
Frequency 24.016 MHz, Channel Width 0.800 MHz, QPSK Symbol Rate 0.640 Msps
Spectrum Group is overridden
SNR 33.2560 dB
Nominal Input Power Level 0 dBmV, Tx Timing Offset 2288
Ranging Backoff automatic (Start 0, End 3)
Ranging Insertion Interval automatic (60 ms)
Tx Backoff Start 0, Tx Backoff End 4
Modulation Profile Group 1
Perform these steps if you are having difficulty with verification:
1.
Use a valid combination of modulation format (QPSK/QAM-16), minislot size, frequency, and
no shutdown.
2.
Use a recommended or previously tested modulation profile. It is not uncommon to create a
modulation profile that does not allow cable interface-to-headend communication. Because each
message type is individually specified, some messages might not work.
3.
Verify using IP ping packets of varying lengths (64 to 1500 bytes). Ping from the headend to the
cable interface.
4.
Verify with your cable interface vendor that CM software is fully certified or compatible with
DOCSIS 1.0 or DOCSIS 1.0 extensions as appropriate.
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Setting the Upstream Input Power Level
The Cisco uBR7100 series CMTS controls the output power levels of CMs to meet the desired upstream
input power level. The nominal input power level for the upstream RF carrier is specified in decibels per
millivolt (dBmV). The default setting of 0 dBmV is the optimal setting for the upstream power level.
The valid range for the input power level depends on the data rate. At 1.6 MHz, the valid range is
–10 to 25 dBmV. If your power levels operate at greater than the maximum valid level, use an inline
attenuator to bring the power level to within the valid range.
Caution
If you increase the input power level, CMs on your HFC network will increase their transmit power level.
This increases the carrier-to-noise ratio (C/N) on the network, but also increases distortion products.
Composite Second Order Beat (CSO) and Composite Triple Beat (CTB) values worsen by 2 dB for every
1 dB-increased C/N. The return path laser immediately enters a nonlinear mode called clipping and all
communication is no longer reliable. Many return lasers send “short” bursts above the clipping
thresholds and fail on longer or successive bursts.
You should not adjust your input power level by more than 5 dB in a 30-second interval. If you increase
the power level by more than 5 dB within 30 seconds, cable interface service on your network is
disrupted. If you decrease the power level by more than 5 dB within 30 seconds, cable interfaces on your
network are forced offline.
Note
When you run the cable upstream 0 power-level command, Cisco recommends that the adjacent
channel not have a large variation. The recommended maximum input power variance is 5 to 6 dBmV.
To set the upstream input power level in dBmV, use the following command in cable interface
configuration mode. Default = 0 dBmV.
CMTS01(config-if)# cable upstream usport power-level dbmv
Verifying the Upstream Input Power Level
To verify the current value of the upstream input power level, enter the show controllers cable command
for the upstream port you have just configured:
CMTS01# show controllers cable1/0 u0
Cable1/0 Upstream 0 is up
Frequency 24.016 MHz, Channel Width 0.800 MHz, QPSK Symbol Rate 0.640 Msps
Spectrum Group is overridden
SNR 33.2560 dB
Nominal Input Power Level 0 dBmV, Tx Timing Offset 2288
Ranging Backoff automatic (Start 0, End 3)
Ranging Insertion Interval automatic (60 ms)
Tx Backoff Start 0, Tx Backoff End 4
Modulation Profile Group 1
Perform these steps if you are having difficulty with verification:
1.
Verify that the upstream amplitude of an optimal RF carrier injected at the fiber node reference input
point reaches the cable modem card input point at a consistent level (node-to-node and port-to-port).
2.
Verify that this absolute level, as installed, matches both the design and software settings on the
Cisco uBR7100 series CMTS.
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Note
Software adjustments of 1 to 3 dB can be used to adjust for minor variations in measurement or setup
and port-to-port calibration differences. These adjustments can significantly improve cable interface
performance, especially in marginal situations. Larger adjustments should be made in conjunction with
spectrum analyzer-support at the headend or distribution hub.
Activating Upstream Admission Control
The admission control is set as a percentage of the specified upstream channel capacity. The acceptable
range is from 10 to 1000 percent. Admission control is disabled by default.
To set the upstream admission control as a percentage of the upstream channel capacity, use the
following command in cable interface configuration mode. Valid range is from 10 to 1000 percent.
CMTS01(config-if)# cable upstream usport admission-control percentage
Verifying Upstream Admission Control
To determine if upstream admission control is configured and activated, enter the show running-config
command in privileged EXEC mode and look for the cable interface configuration information. If
upstream admission control is configured and enabled, an admission control entry displays in the
show running-config output, indicating the user-defined percentage of upstream channel capacity
allowable. If upstream admission control is disabled, no admission control entry displays in the output.
Perform these steps if you are having difficulty with verification:
1.
Ensure the cable connections are not loose or disconnected
2.
Ensure the cable modem card is firmly seated in its chassis slot.
3.
Ensure the captive installation screws are tight.
4.
Verify that you have entered the correct slot and port numbers.
5.
Verify that you selected a valid frequency for your router.
Activating Upstream Forward Error Correction (FEC)
The Cisco uBR7100 series CMTS uses forward error correction (FEC) to attempt to correct any
upstream data that might have been corrupted. FEC is activated by default and should not be disabled.
When FEC is activated, all cable modems on the network also activate FEC.
Note
Although upstream FEC is an option, Cisco recommends that you use upstream FEC.
To activate the upstream forward error correction and to enable FEC, use the following command in
cable interface configuration mode. FEC is enabled by default.
CMTS01(config-if)# cable upstream usport fec
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Verifying Upstream FEC
To verify if FEC is activated or deactivated, enter the more system:running-config command and look
for the cable interface configuration information. If FEC is enabled, an FEC entry displays in the
show running-config output. If FEC is disabled, no FEC entry displays in the output.
Perform these steps if you are having difficulty with verification:
1.
Ensure the cable connections are not loose or disconnected.
2.
Ensure the cable modem card is firmly seated in its chassis slot.
3.
Ensure the captive installation screws are tight.
4.
Verify that you have entered the correct slot and port numbers.
5.
Verify that you selected a valid frequency for your router.
Specifying Upstream Minislot Size
To specify the minislot size (in ticks) for specific upstream cable interfaces, use the following command
in cable interface configuration mode. Acceptable values are 2, 4, 8, 16, 32, 64, and 128. Default = 8.
CMTS01(config-if)# cable upstream usport minislot-size size
Verifying Upstream Minislot Size
To verify upstream minislot size, enter the show controllers cable command for the upstream port you
have just configured:
CMTS01# show controllers cable1/0 u0
Cable1/0 Upstream 0 is up
Frequency 24.016 MHz, Channel Width 1.600 MHz, QPSK Symbol Rate 1.280 Msps
Spectrum Group is overridden
SNR 33.2560 dB
Nominal Input Power Level 0 dBmV, Tx Timing Offset 2288
Ranging Backoff automatic (Start 0, End 3)
Ranging Insertion Interval automatic (60 ms)
Tx Backoff Start 0, Tx Backoff End 4
Modulation Profile Group 1
part_id=0xFFFF, rev_id=0xFF, rev2_id=0xFF
nb_agc_thr=0x0000, nb_agc_nom=0x0000
Range Load Reg Size=0x58
Request Load Reg Size=0x0E
Minislot Size in number of Timebase Ticks is = 8
Minislot Size in Symbols = 64
Bandwidth Requests = 0xFE
Piggyback Requests = 0xD
Invalid BW Requests= 0x2
Minislots Requested= 0x2963
Minislots Granted = 0x2963
Minislot Size in Bytes = 16
Map Advance = 4000 usecs
UCD Count = 32964
DES Ctrl Reg#0 = C000C043, Reg#1 = 0
Perform these steps if you are having difficulty with verification:
1.
Ensure the cable connections are not loose or disconnected.
2.
Ensure the cable modem card is firmly seated in its chassis slot.
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3.
Ensure the captive installation screws are tight.
4.
Verify that you have entered the correct slot and port numbers.
5.
Verify that you selected a valid frequency for your router.
Activating the Upstream Scrambler
The scrambler on the upstream RF carrier enables cable modems on the HFC network to use built-in
scrambler circuitry for upstream data transmissions. The scrambler circuitry improves reliability of the
upstream receiver on the cable modem card.
Caution
The upstream scrambler is activated by default and should not be disabled under normal circumstances.
Disabling it can result in corrupted packets. Disable it only for prototype modems that do not support
the upstream scrambler.
To activate the upstream scrambler, use the following command in cable interface configuration mode.
The upstream scrambler is enabled by default.
CMTS01(config-if)# cable upstream usport scrambler
Verifying the Upstream Scrambler
To determine if the upstream scrambler is activated, enter the more system:running-config command
and look for the cable interface configuration information.
Perform these steps if you are having difficulty with verification:
1.
Ensure the cable connections are not loose or disconnected.
2.
Ensure the cable modem card is firmly seated in its chassis slot.
3.
Ensure the captive installation screws are tight.
4.
Verify that you have entered the correct slot and port numbers.
5.
Verify that you selected a valid frequency for your router.
Activating Upstream Differential Encoding
To enable differential encoding on upstream traffic to a specified cable interface, use the following
command in cable interface configuration mode. Upstream differential encoding is enabled by default.
CMTS01(config-if)# cable upstream usport differential-encoding
Verifying Upstream Differential Encoding
To determine if upstream differential encoding is activated, enter the show running-config command
and look for the cable interface configuration information. If upstream differential encoding is enabled,
a differential encoding entry displays in the show running-config output. If upstream differential
encoding is disabled, no differential encoding entry displays in the output.
Perform these steps if you are having difficulty with verification:
1.
Ensure the cable connections are not loose or disconnected.
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Configuring the Upstream Cable Interface
2.
Ensure the cable modem card is firmly seated in its chassis slot.
3.
Ensure the captive installation screws are tight.
4.
Verify that you have entered the correct slot and port numbers.
5.
Verify that you selected a valid frequency for your router.
Activating Upstream Rate Limiting
Upstream rate limiting allows upstream bandwidth requests from rate-exceeding cable modems to be
buffered without incurring TCP-related timeouts and retransmits. This enables the CMTS to enforce the
peak upstream rate for each cable modem without degrading overall TCP performance for the subscriber
CPEs. Upstream grant shaping is per cable interface (SID).
Token bucket policing with shaping is the per-upstream default rate-limiting setting at the CMTS.
Shaping can be enabled or disabled for the token-bucket algorithm.
To enable upstream rate limiting for an upstream port on a Cisco cable modem card, use one of the
following commands in cable interface configuration mode.
Command
Purpose
CMTS01(config-if)# cable upstream usport
rate-limit
Enable rate limiting for the specified upstream
cable interface.
CMTS01(config-if)# cable upstream usport
rate-limit token-bucket
CMTS01(config-if)# cable upstream usport
rate-limit token-bucket shaping
Enable rate limiting for the upstream cable interface
employing the token bucket policing algorithm.
With this command the Cisco uBR7100 series
CMTS automatically drops packets in violation of
allowable upstream bandwidth.
Default. Enable rate limiting for the upstream cable
interface employing the token bucket policing
algorithm with traffic shaping.
Exit back to the EXEC mode so that you can verify
upstream rate limiting.
To disable upstream traffic shaping for an upstream port, enter the following command in cable interface
configuration mode:
CMTS01(config-if)# ^Z
CMTS01#
CMTS01(config-if)# no cable upstream usport rate-limit
Verifying Upstream Rate Limiting
To determine if upstream rate limiting is configured and activated, enter the show running-config
command and look for the cable interface configuration information. If upstream rate limiting is
configured and enabled, a rate limiting entry displays in the show running-config output. If upstream
rate limiting is disabled, no cable upstream rate-limit displays in the output.
You can also perform the following tasks to verify that rate limiting is enabled on the upstream channel:
Step 1
Configure a low-peak upstream rate limit for the cable modem in its QoS profile. Either use the
command line interface to modify the modem’s QoS profile, or edit the modem’s TFTP config file.
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Configuring the Upstream Cable Interface
Step 2
Use a regular rate-limiting algorithm on the upstream without rate shaping and note the drops of the
excess bandwidth requests from this cable modem when it exceeds its peak upstream rate.
Use the show interface cx/y sid counters command to see the bandwidth request drops. Verify that the
upstream rate received by that modem is less than its configured peak rate due to the timeouts and
backoffs produced by the drop in bandwidth requests. Enter the show interface cx/y sid command to see
the input rate at CMTS in bps.
Step 3
Enable grant shaping on the upstream channel by using the new shaping keyword extension to the
token-bucket algorithm CLI command.
Step 4
Make the cable modem exceed its peak upstream rate by generating upstream traffic, and note the effect
of grant buffering (shaping) at the CMTS. If you use cable modem-to-CMTS pings, you will see a
perceivable slowing down of the pings.
Let the pings run for a period to let averages at the CMTS settle; then view the upstream rate received
by this single modem. Use the show interface cx/y command and see the input rate in bps. This value
should be close to the modem’s peak upstream rate. Also note the drop counts for the modem’s SID by
using the show interface sid counters command and verify that the CMTS no longer drops the
bandwidth requests from the cable modem.
The bandwidth request drop count (from previous non-shaping test) remains unchanged when upstream
rate shaping is used, indicating that the CMTS is actually shaping (buffering) the grants for the modem.
Verify that the input rate at the CMTS (from the single rate-exceeded CM) stabilizes close to the
configured peak rate of 128 Kbps.
Perform these steps if you are having difficulty with verification:
1.
Ensure the cable connections are not loose or disconnected.
2.
Ensure the cable modem card is firmly seated in its chassis slot.
3.
Ensure the captive installation screws are tight.
4.
Verify that you have entered the correct slot and port numbers.
5.
Verify that you selected a valid frequency for your router.
Activating Upstream Frequency Adjustment
To enable automatic upstream frequency adjustment for a specified cable interface, use the following
commands in cable interface configuration mode.
Command
Purpose
CMTS01(config-if)# cable upstream
usport frequency-adjust averaging
percentage
Set the minimum number of frequency adjustment
packets required to justify changing the upstream
frequency adjustment method as a percentage.
Acceptable range is 10 to 100 percent.
Default = 30 percent.
CMTS01(config-if)# end
CMTS01#
Return to enable (privileged EXEC) mode.
To return the automatic upstream frequency adjustment percentage to the default value of 30 percent,
enter the following command in cable interface configuration mode:
CMTS01(config-if)# no cable upstream usport frequency-adjust averaging
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Configuring the Upstream Cable Interface
Verifying Upstream Frequency Adjustment
To determine if upstream frequency adjustment is configured and activated, enter the
show running-config command and look for the cable interface configuration information. If upstream
frequency adjustment is enabled, frequency adjustment entries are displayed in the
show running-config output. If frequency adjustments are disabled, no frequency adjustment entry
displays in the output.
Perform these steps if you are having difficulty with verification:
1.
Ensure the cable connections are not loose or disconnected
2.
Ensure the cable modem card is firmly seated in its chassis slot.
3.
Ensure the captive installation screws are tight.
4.
Verify that you have entered the correct slot and port numbers; you selected a valid frequency for
your router.
Activating Upstream Power Adjustment
To enable upstream power adjustment for a specified cable interface, use one of the following commands
in cable interface configuration mode.
Command
Purpose
CMTS01(config-if)# cable upstream usport
power-adjust continue db
Set the minimum power adjustment in dB
that allows continued ranging status. Valid
values are 2 to 15 dB. Default = 2 dB.
CMTS01(config-if)# cable upstream usport
power-adjust noise percentage
Set the minimum number (percentage) of
power adjustment packets required to justify
changing the upstream power rating. Valid
values are 10 to 100 percent. Default = 30
percent.
CMTS01(config-if)# cable upstream 0 power-adjust
threshold db
Set the power adjustment threshold in dB.
Valid values are 0 to 2 dB. Default = 1 dB.
CMTS01(config-if)# end
CMTS01#
Return to enable (privileged EXEC) mode.
To return the automatic upstream power adjustment ranging value to the default of 2 dB, enter the
following command in cable interface configuration mode:
CMTS01(config-if)# no cable upstream usport power-adjust continue
To return the automatic upstream power adjustment noise value to the default of 30 percent, enter the
following command in cable interface configuration mode:
CMTS01(config-if)# no cable upstream usport power-adjust noise
To return the upstream power adjustment threshold value to the default of 1 dB, enter the following
command in cable interface configuration mode:
CMTS01(config-if)# no cable upstream usport power-adjust threshold
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Configuring the Cisco Cable Interface
Configuring the Upstream Cable Interface
Verifying Upstream Power Adjustment
To determine if upstream power adjustment is configured and activated, enter the show running-config
command and look for the cable interface configuration information. If upstream power adjustment is
enabled, any or all three of the continue, noise, and threshold power adjustment entries are displayed
in the show running-config output. If all three continue, noise, and threshold upstream power
adjustments are disabled, no power adjustment entry displays in the show running-config output.
Activating Upstream Timing Adjustment
To enable upstream timing adjustment for a specified cable interface, use one of the following commands
in cable interface configuration mode.
Command
Purpose
CMTS01(config-if)# cable upstream usport
time-adjust continue seconds
Set the minimum timing adjustment that allows
continued ranging status. Valid values are
2 to 64 seconds. Default = 2 seconds.
CMTS01(config-if)# cable upstream usport
time-adjust threshold seconds
Set the timing adjustment threshold value in
seconds. Valid values are 1 to 32 seconds.
Default = 1 second.
CMTS01(config-if)# end
CMTS01#
Return to enable (privileged EXEC) mode.
To return the upstream time adjustment ranging value to the default of 2 seconds, enter the following
command in cable interface configuration mode:
CMTS01(config-if)# no cable upstream usport time-adjust continue
To return the upstream time adjustment threshold value to the default of 1 second, enter the following
command in cable interface configuration mode:
CMTS01(config-if)# no cable upstream usport time-adjust threshold
Verifying Upstream Timing Adjustment
To determine if upstream timing adjustment is configured and activated, enter the show running-config
command and look for the cable interface configuration information. If upstream timing adjustment is
enabled, either or both of the continue and threshold timing adjustment entries are displayed in the
show running-config output. If both the continue and threshold upstream timing adjustments are
disabled, no timing adjustment entry displays in the show running-config output.
Tip
If you are having difficulty with verification, make sure the cable connections are not loose or
disconnected; the cable modem card is firmly seated in its chassis slot; the captive installation screws
are tight; you have entered the correct slot and port numbers.
Activating the Upstream Ports
Each upstream port must be activated to enable upstream data transmission from the cable modems on
the HFC network to the Cisco uBR7100 series CMTS.
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Configuring the Upstream Cable Interface
Note
The upstream cable interface does not operate until you either set a fixed upstream frequency or create
and configure a spectrum group. Refer to the “Setting the Upstream Frequency” section on page 3-10,
or the “Creating Spectrum Groups” section on page 3-28 for details.
To activate the upstream ports, use the following commands in global configuration mode.
Command
Purpose
CMTS01(config)# interface cable slot/port
Specify a cable interface and enter cable interface
configuration mode.
CMTS01(config-if)# no cable upstream
usport shutdown
Enable upstream data traffic.
Verifying the Upstream Ports
To determine if the upstream ports are activated or deactivated, enter the show interface cable command
for the upstream port just configured:
router# show interface cable1/0
Cable1/0 is up, line protocol is up
Hardware is BCM3210 FPGA, address is 00e0.1e5f.7a60 (bia 00e0.1e5f.7a60)
Internet address is 1.1.1.3/24
MTU 1500 bytes, BW 27000 Kbit, DLY 1000 usec, rely 255/255, load 1/255
Encapsulation, loopback not set, keepalive not set
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:25, output 00:00:00, output hang never
Last clearing of “show interface” counters never
Queuing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/75, 0 drops
5 minute input rate 0 bits/sea, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
10878 packets input, 853740 bytes, 0 no buffer
Received 3679 broadcasts, 0 runts, 0 giants, 0 throttles
3 input errors, 3 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
5401 packets output, 645885 bytes, 0 underruns
0 output errors, 0 collisions, 9 interface resets
0 output buffer failures, 0 output buffers swapped out
Setting Upstream Backoff Values
The DOCSIS-specified method of contention resolution for cable modems wanting to transmit data or
requests on the upstream channel is a truncated binary exponential backoff, with the initial backoff
window and the maximum backoff window controlled by the CMTS. The Cisco uBR7100 series CMTS
specifies backoff window values for both data and initial ranging, and sends these values downstream as
part of the Bandwidth Allocation Map (MAP) MAC message.
The values are configurable on the Cisco uBR7100 series software and are power-of-two values. For
example, a value of 4 indicates a window between 0 and 15; a value of 10 indicates a window between
0 and 1023. You can set fixed start and end values for data backoff on the upstream ports, or you can set
the upstream ports for automatic data backoff. You have the same options for ranging backoff. For both
backoff windows, the default start value is 0; the default end value is 4. Valid values are from 0 to 15.
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Configuring the Upstream Cable Interface
Note
Cisco does not recommend you adjust default values, but enable the automatic dynamic backoff
algorithm. Refer to the “Configuring Dynamic Contention Algorithms (Cable Insertion Interval, Range,
and Data Backoffs)” section on page 5-4.
To set data or ranging backoff values for an upstream port, use one or more of the following commands,
in cable interface configuration mode.
Command
Purpose
CMTS01(config-if)# cable upstream
usport data-backoff start end
The automatic setting is optimized for as many as 250
cable interfaces per upstream port. Set manual values for data
backoff windows only when operating with more than 250
cable interfaces per upstream port.
or
CMTS01(config-if)# cable upstream
usport data-backoff automatic
This command configures the default backoff window values
of 0 and 4.
CMTS01(config-if)# cable upstream
usport range start end
The automatic setting is optimized for as many as 250
cable interfaces per upstream port. Set manual values for data
backoff windows only when operating with more than 250
cable interfaces per upstream port.
or
CMTS01(config-if)# cable upstream
usport range automatic
This command configures the default backoff window values
of 0 and 4.
When considering whether to adjust backoff values, keep the following in mind:
•
The cable interface reconnection time after a power outage is related to the following factors:
– DHCP, TOD, and TFTP server capacity. These servers often operate well below 1% load under
normal situations, but can jump to over 100% after an outage.
– Adjusting the backoffs to larger numbers slows cable interface reconnection and reduces server
load.
– Backoffs which are too small result in cable interfaces failing to range the upstream RF levels
correctly and cycling to maximum power, thus increasing connection time and reducing
network performance.
– Backoffs which are too large result in increased recovery time after a large service outage.
– There is significant variation in cable interface performance (brand to brand) in cable interface
restart time.
•
All cable interfaces should recover between approximately 0 to 10 minutes after all services are
restored (Cisco uBR7100 series, RF transport, DHCP/TFTP/TOD servers). Cable modems taking
longer than 10 minutes could indicate a problem in the cable modem, in CMTS settings, or in the
DOCSIS provisioning servers.
Note
Upstream segments serving a relatively large number of cable interfaces (for example, more
than 1600) might suffer recovery times greater than 10 minutes.
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Enabling and Configuring Baseline Privacy
Verifying Upstream Data Backoff Automatic
To verify backoff window settings, enter the show controllers cable command for the upstream port you
have just configured:
CMTS01# show controllers cable1/0 u0
Cable1/0 Upstream 0 is up
Frequency 24.016 MHz, Channel Width 1.600 MHz, QPSK Symbol Rate 1.280 Msps
Spectrum Group is overridden
SNR 33.2560 dB
Nominal Input Power Level 0 dBmV, Tx Timing Offset 2288
Ranging Backoff automatic (Start 0, End 3)
Ranging Insertion Interval automatic (60 ms)
Tx Backoff Start 0, Tx Backoff End 4
Modulation Profile Group 1
part_id=0x3137, rev_id=0x03, rev2_id=0xFF
nb_agc_thr=0x0000, nb_agc_nom=0x0000
Range Load Reg Size=0x58
Request Load Reg Size=0x0E
Minislot Size in number of Timebase Ticks is = 8
Minislot Size in Symbols = 64
Bandwidth Requests = 0xFE
Piggyback Requests = 0xD
Invalid BW Requests= 0x2
Minislots Requested= 0x2963
Minislots Granted = 0x2963
Minislot Size in Bytes = 16
Map Advance = 4000 usecs
UCD Count = 32964
DES Ctrl Reg#0 = C000C043, Reg#1 = 0
Enabling and Configuring Baseline Privacy
Introduction to the Baseline Privacy Interface (BPI)
BPI gives subscribers data privacy across the RF network, encrypting traffic flows between the CMTS
and CM. The level of data privacy is roughly equivalent to that provided by dedicated line network access
services such as analog modems or digital subscriber lines (DSL). BPI provides basic protection of
service, ensuring that a CM, uniquely identified by its MAC address, can obtain keying material for
services only it is authorized to access.
Note
Encryption/decryption is subject to export licensing controls.
Note
Because DOCSIS 1.0 BPI does not authenticate CMs, it does not protect against users employing cloned
CMs, masquerading as authorized CMs. Specific Cisco IOS releases provide protection against
spoofing, and support commands that can be used to configure source IP filtering on RF subnets to
prevent a user from using a source IP address that is not valid for the connected IP subnet.
BPI is defined as a set of extended services within the DOCSIS MAC sublayer. Refer to the DOCSIS
Baseline Privacy Interface Specification for detailed requirements.
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Enabling and Configuring Baseline Privacy
BPI extends the definition of the MAC sublayer’s SID. The DOCSIS RF Interface Specification defines
a SID as a mapping between CMTS and CM to allocate upstream bandwidth and class of service
management. When BPI is activated, the SID also identifies a particular security association and has
upstream and downstream significance. When BPI is operational, downstream multicast traffic flow that
typically does not have a SID associated with it, now has a SID. The Privacy Extended Header Element
includes the SID associated with the MAC Packet Data Physical Data Unit (PDU). The SID and other
components of the extended header element identify to a CM the keying material required to decrypt the
MAC PDU’s packet data field.
BPI’s key management protocol runs between the CMTS and the CM. CMs use the protocol to obtain
authorization and traffic keying material relevant to a particular SID from the CMTS, and to support
periodic reauthorization and key refresh.
The key management protocol uses RSA—a public key encryption algorithm—and the electronic
codebook (ECB) mode of DES to secure key exchanges between the CMTS and a CM. Privacy is in the
form of 56-bit (the default) or 40-bit encryption between the CMTS and CM. Since BPI is part of
DOCSIS, all DOCSIS-certified CMs and qualified CMTS are fully interoperable. Figure 3-1 shows a
BPI architecture.
Note
CMs must have factory-installed RSA private/public key pairs to support internal algorithms to generate
key pairs prior to first BPI establishment.
A SID’s keying material has a limited life span. When the CMTS delivers SID keying material to a CM,
it also provides the CM with the lifetime value.
BPI Network Example
A
Cable
modem
B
Cable
modem
C
Cable
network
Cable
modem
Cisco
uBR7100 series
CMTS
Internet
MSO
network
37394
Figure 3-1
Segment secured by baseline privacy
BPI Key Management
BPI initialization begins with the CM sending the CMTS an authorization request, containing data
identifying:
•
CM—48-bit IEEE MAC address
•
CM’s RSA public key
•
List of zero or more assigned unicast SIDs that have been configured to run BPI
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Enabling and Configuring Baseline Privacy
At that time, BPI provides basic protection against theft of service by ensuring the CM, identified by its
MAC address, can obtain keying materials only it is authorized to access. The CMTS replies with a list
of SIDs on which to run BPI. The reply also includes an authorization key from which the CM and CMTS
derive the keys needed to secure a CM’s subsequent requests for additional encryption keys. After
obtaining the traffic encryption key, the CMs begin to transmit encrypted data.
Differentiating Traffic Streams
BPI only encrypts data on the cable network and only encrypts the user data itself, not cable MAC
headers. BPI also does not encrypt MAC management messages.
After BPI is enabled, however, and encryption has been negotiated for a given SID, all user data sent
using that SID is encrypted. BPI differentiates traffic, based on the SID alone.
CM Communication with BPI
Figure 3-2 illustrates BPI communications. When user A sends packets to user B, the CM encrypts those
packets using special keys specific to the user’s CM. Packets are then transmitted to the CMTS where
they are decrypted.
If user B is attached to the cable TV network, the CMTS then re-encrypts the information using a key
specific to user B, and the encrypted data is passed to user B’s CM where it is decrypted and sent to user
B. In this manner, an unauthorized user is not able to see unencrypted traffic between user A and user B.
Caution
Since BPI occurs only on the cable TV network, however, all traffic going upstream is decrypted as it
passes the CMTS. If user A is attempting to communicate with someone beyond the cable network—user
C—all traffic beyond the CMTS is not encrypted.
Figure 3-2
A
B
BPI Encrypted Data on the Cable TV Network
Cable
modem
Cable
modem
Cable
network
Cisco
uBR7100 series
CMTS
Internet
MSO
network
C
37395
Communication from A to B
(cable network only) is secured by BPI
Communication from A to C (cable network and other networks)
is not fully secured by BPI
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Configuring the Cisco Cable Interface
Enabling and Configuring Baseline Privacy
Enabling BPI
To enable BPI, choose software images at both the CMTS and CM that support the mode of operation.
For the Cisco uBR7100 series software, choose an image with “k1” in its file name or BPI in the
feature set description. For Cisco uBR924 cable access routers, all CM images from
Cisco IOS Release 12.0(5)T1 or later support this by default. For earlier Cisco IOS release CM images,
choose an image with “k1” in its file name or BPI in the feature set description.
Note
For the CMTS, BPI is enabled by default when you select an image that supports BPI. For CMs, enable
BPI using the DOCSIS configuration file using the instructions that follow in this section.
When baseline privacy is enabled, the Cisco uBR7100 series router generates traffic encryption keys
(TEKs) for each applicable SID; 56-bit encryption/decryption is the default for Cisco uBR7100 series
equipment.
The router uses the keys to encrypt downstream data and decrypt upstream traffic from two-way
cable interfaces. The Cisco uBR7100 series router generates keys for unicast, broadcast, and multicast
operation as appropriate. Keys are refreshed periodically and have a default lifetime of 12 hours.
Configuring Baseline Privacy
Note
Both the CMTS and the CM must support baseline privacy and have BPI enabled.
To configure baseline privacy (deviating from default values), follow procedures in this section:
•
“Configuring Key Encryption Key (KEK) Privacy” section on page 3-26
•
“Configuring Traffic Encryption Key (TEK) Privacy” section on page 3-27
•
“Activating Baseline Privacy” section on page 3-27
Configuring Key Encryption Key (KEK) Privacy
A lifetime KEK can be set from 86400 to 6048000 seconds. If you do not set a KEK value, the default
values are used.
To configure KEK data privacy on the HFC network, enter one of the following commands in cable
interface configuration mode.
Command
Purpose
CMTS01(config-if)# cable privacy kek life-time seconds
Set the cable privacy KEK lifetime in seconds. Valid values
are from 86400 to 6048000 seconds.
Default = 604800.
Verifying KEK Privacy
To verify the KEK lifetime values that are set, enter the show cable privacy kek command:
CMTS01# show cable privacy kek
Configured KEK life time value = 750000
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Tip
If you are having difficulty with verification, make sure you have entered a valid value for lifetime.
Configuring Traffic Encryption Key (TEK) Privacy
A lifetime TEK can be set from 1800 to 604800 seconds. If you do not set a TEK value, the defaults are
used.
To configure TEK data privacy on the HFC network, use the following commands in cable interface
configuration mode.
Command
Purpose
CMTS01(config-if)# cable privacy tek life-time seconds
Set the cable privacy TEK life time in seconds. Valid
values are from 1800 to 604800 seconds.
Default = 43200 seconds.
Verifying TEK Privacy
To verify the TEK lifetime values that are set, enter the show cable privacy tek command:
CMTS01# show cable privacy tek
Configured TEK life time value = 56000
Activating Baseline Privacy
BPI is activated by default when using an image that supports baseline privacy. Commands in the cable
interface configuration mode are as follows:
Command
Purpose
CMTS01(config-if)# cable privacy enable
Activate cable privacy. This is the default.
CMTS01(config-if)# cable privacy mandatory
Activate cable privacy and do not allow access for
any unencrypted cable modem connections.
Verifying Baseline Privacy
To determine if baseline privacy is activated, enter the show interface privacy command. When using
a Cisco uBR7100 series “k1” image, cable privacy is enabled by default and can only be disabled with
the no cable privacy command. The cable modem must also be configured to support baseline privacy.
Tip
If you are having difficulty with verification, make sure you entered a valid value for lifetime for KEK
and TEK privacy.
Note
If you entered the cable privacy mandatory command, then cable interfaces do not operate unless the
cable interface configuration file specifies that privacy is on.
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Configuring and Activating Frequency Agility
Configuring and Activating Frequency Agility
Set upstream port frequency to a fixed value during system installation and testing. Choose this value
from your frequency allocation plan for the RF plant segment connected to the upstream.
When the system has reached sufficient stability, the RF domain topology can be entered into the
configuration file to enable spectrum management. Spectrum management or frequency agility is
configured and activated using spectrum groups.
Frequency-hopping policies supported on all Cisco cable modem cards include combined blind and
scheduled specifications, as well as guided frequency hops.
Note
The cable interface will not operate until you either create and configure a spectrum group or set a fixed
upstream frequency. From the interface configuration prompt, an interface is assigned membership in a
spectrum group. From the interface point of view, the spectrum group also represents the set of
upstreams connected to the same group of fiber nodes. This allows the spectrum manager to know if
upstream frequencies need to be managed together.
To configure and activate frequency agility, perform the following tasks:
•
“Creating Spectrum Groups” section on page 3-28
•
“Configuring and Activating Spectrum Groups” section on page 3-29
•
“Configuring Spectrum Group Characteristics” section on page 3-32
Creating Spectrum Groups
To create a spectrum group, use one of the following general commands in global configuration mode.
Command
Purpose
CMTS01(config)# cable spectrum-group
group-number type scheduled daily
Create a scheduled spectrum group that can
change its frequency and power level at the
same time every day.
CMTS01(config)# cable spectrum-group
group-number type scheduled periodic-sec seconds
Create a scheduled spectrum group that can
change its frequency and power level at a
specified interval in seconds.
Frequency agility is configured and activated using spectrum groups. You can create from 1 to 32
spectrum groups for each cable interface card upstream port.
To create spectrum groups, specify a list of upstream frequencies and nominal power levels that each
spectrum group can use when an upstream frequency change is necessary. Each spectrum group should
have its own list of upstream frequencies.
After you have created one or more spectrum groups, you can add characteristics to them, providing
more definitive control over frequency usage and frequency hopping. See the “Configuring and
Activating Spectrum Groups” section on page 3-29.
Verifying Spectrum Groups
To verify that a spectrum group is created, enter the show cable spectrum-group command:
CMTS01# show cable spectrum-group
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spectrum-group 1
spectrum-group 2
spectrum-group 3
Tip
If you are having difficulty with verification, make sure you have entered a valid spectrum group number
and type.
Configuring and Activating Spectrum Groups
After you create a spectrum group, configure a list of upstream frequencies and optional nominal power
levels that each spectrum group can use when an upstream frequency change is necessary. Each spectrum
group should have its own list of upstream frequencies.
Note
Valid frequencies are 5,000,000 to 42,000,000 Hz for NTSC operations and 5,000,000 to 65,000,000 for
EuroDOCSIS 8 MHz operations.
To configure and activate a spectrum group, use the following commands in global configuration mode.
Command
Purpose
CMTS01(config)# cable spectrum-group
group-number [time day hh:mm:ss] [delete]
frequency ctr-freq-hz [power-level-dbmv]
Add the upstream frequency to the list of valid
frequencies with a default power level for a
spectrum group.
Note
CMTS01(config)# cable spectrum-group
group-number [time day hh:mm:ss] [delete] band
start-freq-hz end-freq-hz [power-level-dbmv]
If the time parameter is configured,
the frequency setting or band is either
made available or deleted at the
specified time.
The power level value should only be changed
if you want to change the power level as part
of spectrum management. The standard power
level is 0 dBmV.
Note
Configuring a spectrum group enables frequency agility and disables the fixed upstream frequency
setting.
Tip
You must repeat one of the previous command for each frequency or power level that you want to add to
a spectrum group’s list of valid values.
If your cable plant has an upstream noise characteristic on a weekly cycle, use time-scheduled spectrum
allocation:
CMTS01(config)# cable spectrum-group 1 time Mon 08:00:00 frequency 21600000
Deletion is performed using the delete keyword:
CMTS01(config)# cable spectrum-group 1 time Mon 18:00:00 delete frequency 21600000
The following example displays a spectrum group configuration that is designed to perform minor
equalization as a function of frequency.
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CMTS01(config)# cable spectrum-group 1 frequency 21600000
CMTS01(config)# cable spectrum-group 1 frequency 24800000 1
CMTS01(config)# cable spectrum-group 1 frequency 28000000 2
In the previous example, the upstream port nominal receive power at 21.6 MHz is 0 dBmV, at 24.8 MHz
is 1 dBmV, and at 28.0 MHz is 2 dBmV. At any time, the power level set in the interface configuration
overrides the spectrum group power level.
The following example enables spectrum management for all upstream ports, assuming that all combiner
groups use the frequency band from 20 to 26 MHz:
CMTS01(config)# cable spectrum-group 1 band 20000000 26000000
CMTS01(config)# cable spectrum-group 2 shared
CMTS01(config)# cable spectrum-group 2 band 20000000 26000000
CMTS01(config)# cable spectrum-group 3 shared
CMTS01(config)# cable spectrum-group 3 band 20000000 26000000
CMTS01(config)# interface Cable1/0
CMTS01(config-if)# cable spectrum-group 1
CMTS01(config-if)# cable upstream 2 spectrum-group 2
CMTS01(config-if)# cable upstream 3 spectrum-group 2
CMTS01(config-if)# exit
For the 20 to 26 MHz band of each RF domain, the spectrum is channelized according to the
channel width settings of each member port. For example, if the ports U2 and U3 of Cable1/0 are set to
3.2 MHz and 1.6 MHz channel widths, respectively, then spectrum group 2 uses the following
channelization:
>
>
>
>
>
>
Note
Channel Width Start Stop Center
(Mhz) (Mhz) (Mhz) (Mhz)
1
3.2
20.0 23.2 21.6
2*
1.6
20.0 21.6 20.8
3*
1.6
21.6 23.2 22.4
4
1.6
23.2 24.8 24.0
Channels 2 and 3 are not available when channel 1 is in use.
Because the group is shared, ports U2 and U3 will be assigned channels 1 and 4, respectively, to prevent
overlap.
Note
There are no alternate frequency assignments for either port and bandwidth is wasted from 24.8 to
26.0 MHz. To create alternate channels, increase the upper boundary from 26.0 to 28.0 MHz.
> Channel
>
> 1
> 2
> 3
> 4
> 5
> 6
> 7
Width Start Stop Center
(Mhz) (Mhz) (Mhz) (Mhz)
3.2
20.0 23.2 21.6
3.2
23.2 26.4 24.8
1.6
20.0 21.6 20.8
1.6
21.6 23.2 22.4
1.6
23.2 24.8 24.0
1.6
24.8 26.4 25.6
1.6
26.4 28.0 27.4
Care should be taken to reduce the spectrum allocation when used with small channel widths. Otherwise,
there will be a large number of upstream channel slots.
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For example, if the allocation is from 20.0-to-28.0 MHz and an upstream port has its channel width set
to 0.2 MHz, there are 40 possible slots for that channel width. Blind frequency hopping can require a
long time to find the clean slot, because it tries each available slot, one at a time for several seconds
during each try.
Verifying Spectrum Group Configuration
To verify if spectrum groups are configured and activated, enter the show cable spectrum-group
command:
CMTS01# show cable spectrum-group
22:07:46: %SYS-5-CONFIG_I: Configured from console by console
Group Frequency
Upstream
Weekly Scheduled
No.
Band
Port
Availability
(Mhz)
From Time:
To Time:
1
5.000-15.000
1
12.000
1
22.000
2
29.000
2
26.000
3
35.000-41.000
3
16.000-19.000
5*
5.000-10.000
Thu 21:50:00 Thu 21:45:00
Power
Level
(dBmV)
0
0
7
6
0
0
5
0
Shared
Spectrum
Yes
Yes
Yes
No
No
No
No
Yes
Verifying Frequency Hopping
To verify frequency hopping on the Cisco uBR7100 series CMTS, note the following:
•
The controller must report being up.
•
The comparison of the number of errors versus the number of error-free packets is a measure of the
link quality. The percentage of errors should be less than 1%.
After you have established basic operation, inject a tone to the upstream port. For example, if the
upstream frequency is currently 22.4 MHz, inject a 22.4 MHz tone at approximately the same power
level as the modem. If the power level at the modem is 40 dBmV, set the tone power to 40 dBmV. The
interfering carrier should shut down the channel and cause the frequency to change to the next configured
value. In this example, it would be 24.0 MHz.
If you do not have an RF tone generator, use another cable modem card and modem that carries traffic.
Connect the upstream to the same combiner group, and use the data carrier as an interfering signal by
setting it to the same frequency. For example, to test frequency hopping on c1/0, install c1/0 and connect
both upstreams together using a combiner. If the upstream frequency of c1/0 is currently 22.4 Mhz, set
c1/0 to 22.4 MHz while c1/0 is carrying traffic. This should force c1/0 to change the frequency to the
next configured value.
Tip
If you are having difficulty with verification, make sure you entered a valid spectrum group number,
time, frequency, and input power level.
When defining your spectrum, avoid frequencies with known ingress problems such as amateur radio
bands or short-wave bands and spectrum below 20 MHz; allow extra bands for frequency hopping; place
upstream ports in the same combiner group in a shared spectrum group; use the receive power level
setting to perform slight equalization adjustments.
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Configuring Spectrum Group Characteristics
After you have created one or more spectrum groups, add characteristics to them. As stated in the
DOCSIS RFI specification, RF channel migration occurs by broadcasting a change in the upstream
channel descriptor (UCD) message to all cable interfaces. The UCD message contains the upstream
frequency and transmission parameters associated with an upstream channel.
The speed of channel migration via the UCD message is typically less than 20 milliseconds (ms). During
this time, upstream transmission is interrupted until the cable interface transmitter adjusts to its new
frequency. Data is stored in the cable interface’s buffers during this time and is sent when the frequency
hop is complete.
Also, per the DOCSIS RFI, station maintenance intervals are used to perform per-modem keepalive
polling. The Cisco uBR7100 series poll each cable interface. When ingress noise causes loss of
keepalive messages from a configurable percentage of all cable interfaces, resulting in those cable
modems going offline, a new frequency is selected from the allocation table and a UCD update is
performed.
Note
Also see the “Polling Cable Modems” section on page 5-15.
The migration time is 10 seconds (maximum) for the decision and 20 ms for the frequency hop. The
percentage threshold method prevents a single failing cable interface from affecting service to other
good cable interfaces. The system will not hop endlessly because one cable interface is generating 90%
of the errors and 90% of the traffic.
The minimum period between frequency hops is also configurable, with a default setting of 300 seconds.
If the destination channel is expected to be impaired, the minimum period between frequency hops can
be reduced to a small value such as 10 seconds. This allows the frequency hop to continue more rapidly
until a clear channel is found. If excessive frequency hop is an issue, the minimum period between hops
can be increased.
To adjust the frequency hop threshold percentage or the minimum period between frequency hops, use
the following commands in global configuration mode.
Command
Purpose
CMTS01(config)# cable spectrum-group
groupnum hop threshold percent
Set the percentage of all cable modems losing keepalive
messages (going offline) that will cause a frequency hop.
CMTS01(config)# cable spectrum-group
groupnum hop period seconds
Set the minimum time between frequency hops in seconds.
Valid values are from 1 to 3600 seconds.
To specify that a particular spectrum group is a shared RF spectrum group, use the following command
in global configuration mode.
Command
Purpose
CMTS01(config)# cable spectrum-group
groupnum shared
Specifying a given spectrum group as “shared” tells the
Cisco uBR7100 series CMTS that you want to be sure that
upstream frequencies assigned to upstream interfaces are
not assigned to additional upstream interfaces.
Table 3-1 describes the spectrum-group parameters.
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Table 3-1
spectrum-group parameters
Syntax
Valid Values
group number
Specifies the spectrum group for which you are specifying a parameter value or specifies the number of the
spectrum group you wish to remove from your router configuration. Valid range is from 1 to 32.
parameter
The spectrum group values that can be changed or added are:
•
Frequency—Specifies the center frequency for the given spectrum group. Entering additional
cable spectrum-group group number frequency commands for the same spectrum group creates a
collection of allowable center frequencies for spectrum group hopping.
•
Band—Specifies a range of center frequencies the Cisco uBR7100 series router can scan in order to find
an acceptable channel to which the spectrum group can hop.
•
Time—Specifies a time of day that the Cisco uBR7100 series router should automatically perform a
frequency hop for the given upstream spectrum group.
The time command can be combined with the frequency and band commands.
Note
value
•
Hop period—Specifies the minimum period (in seconds) before which a frequency hop can occur.
•
Hop threshold—The threshold value (expressed as a percentage) of the number of “offline” modems
identified before the Cisco uBR7100 series router initiates an automatic frequency hop.
•
Shared—Specifies that a particular spectrum group is a shared RF spectrum group; upstream
frequencies assigned to upstream interfaces are not to be assigned to additional upstream interfaces.
The corresponding parameter value for the parameter you are defining for a given spectrum group.
Examples are provided to configure differing spectrum groups:
•
Use the following example to configure spectrum group 1 with an upstream frequency of
6,500,000 Hz and a default power level of 0 dBmV:
Router(config)# cable spectrum-group 1 frequency 6500000
•
Use the following example to add the upstream frequency 7,000,000 Hz to the list of valid
frequencies with a default power level of 0 dBmV for spectrum group 1:
Router(config)# cable spectrum-group 1 frequency 7000000
•
Use the following example to configure spectrum group 2 with an upstream frequency 7,500,000 Hz
and change the power level to 5 dBmV:
Router(config)# cable spectrum-group 2 frequency 7500000 5
•
Use the following example to configure spectrum group 3 with an upstream band of 12,000,000 to
18,000,000 Hz and default power level of 0 dBmV:
Router(config)# cable spectrum-group 3 band 12000000 18000000
•
Use the following example to add the upstream band 20,000,000 to 24,000,000 Hz to the list of valid
bands with a change in the power level of 13 dBmV for spectrum group 3:
Router(config)# cable spectrum-group 3 band 20000000 24000000 13
•
Use the following example to configure a continuous band between 5,000,004 and 40,000,000 Hz
for scheduled spectrum group 4 with a default power level of 0 dBmV. The spectrum group will be
available to the spectrum group starting at 12:00 p.m. local time each Monday:
Router(config)# cable spectrum-group 4 time Monday 12:00:00 band 5000004 40000000
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•
Use the following example to add the upstream frequency 9,500,000 Hz to the list of valid
frequencies and change the nominal power level to 5 dBmV. The spectrum manager adjusts
frequencies and power levels on this group at 2:00 a.m. local time each day:
Router(config)# cable spectrum-group 3 time 02:00:00 frequency 9500000 5
•
Use the following example to configure the minimum period before which a frequency hop can
occur in seconds:
Router(config)# cable spectrum-group 3 hop period 800
•
Use the following example to configure the threshold value (expressed as a percentage) of the
number of “offline” modems identified before the Cisco uBR7100 series router initiates an
automatic frequency hop:
Router(config)# cable spectrum-group 3 hop threshold 40
•
Use the following example to configure a particular spectrum group as a shared RF spectrum group.
Specifying a given spectrum group as “shared” tells the Cisco uBR7100 series router that you want
to be sure that upstream frequencies assigned to upstream interfaces are not assigned to additional
upstream interfaces:
Router(config)# cable spectrum-group 3 shared
•
Use the following example to remove a specified spectrum group from your configuration:
Router(config)# no cable spectrum-group 3
Verifying Spectrum Group Characteristics
To verify spectrum group characteristics and to determine if a spectrum group is shared, use the
show cable spectrum-group command:
CMTS01# show cable spectrum-group
22:07:46: %SYS-5-CONFIG_I: Configured from console by console
Group Frequency
Upstream
Weekly Scheduled
No.
Band
Port
Availability
(Mhz)
From Time:
To Time:
1
5.000-15.000
1
12.000
1
22.000
2
29.000
2
26.000
3
35.000-41.000
3
16.000-19.000
5*
5.000-10.000
Thu 21:50:00 Thu 21:45:00
Tip
Power
Level
(dBmV)
0
0
7
6
0
0
5
0
Shared
Spectrum
Yes
Yes
Yes
No
No
No
No
Yes
If you are having difficulty with verification, make sure you entered a valid spectrum group number and
type in global cable configuration mode.
Assigning the Spectrum Group and the Upstream Ports
After determining which upstream ports you want assigned to a combiner group, perform the following
steps to configure a frequency hop table.
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Activating Cable Address Resolution Protocol Requests
Command
Purpose
Step 1
CMTS01(config)# interface cable slot/port
Enter cable interface configuration mode for the interface
to which you wish to assign a spectrum group.
Step 2
CMTS01(config-if)# cable spectrum-group usport
Assign the spectrum group to the interface.
Step 3
CMTS01(config-if)# cable upstream number
spectrum-group usport
Assign the upstream ports to the spectrum group for the
interface.
Step 4
CMTS01(config-if)# no cable upstream slot/port
shutdown
Place the upstream port in the “admin up” state.
Step 5
CMTS01(config-if)# exit
CMTS01# test cable hop c1/0
CMTS01# test cable hop c1/0
Exit configuration mode and force the system to hop.
Verifying Spectrum Group and Upstream Port Assignments
Use the show cable spectrum-group command to display the current allocation table and frequency
assignments.
Activating Cable Address Resolution Protocol Requests
Address Resolution Protocol (ARP) is an Internet protocol used to map IP addresses to MAC addresses
on computers and other equipment installed in a network. You need to activate ARP requests on the cable
interface so that the Cisco uBR7100 series CMTS can perform IP address resolution on the downstream
path.
Note
The default values for the commands used in this configuration step are adequate in most cases to
configure the Cisco uBR7100 series CMTS.
Activating Cable Address Resolution Protocol (ARP) Requests
To activate ARP requests, use the following command in cable interface configuration mode:
Command
Purpose
CMTS01(config-if)# cable arp
Enable ARP. This is the default.
Verifying ARP Requests
To verify if cable ARP is activated, enter the more system:running-config and look for the cable
interface configuration information. If ARP is activated, it does not appear in this output. If ARP is
deactivated, it appears in the output as no cable arp.
CMTS01# more system:running-config
Building configuration...
Current configuration:
!
interface Cable1/0
ip address 1.1.1.1 255.255.255.0
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no keepalive
no cable arp
cable downstream annex B
cable downstream modulation 64qam
cable downstream interleave-depth 32
cable downstream symbol-rate 5056941
cable upstream 0 frequency 15008000
no cable upstream 0 shutdown
Tip
If you are having difficulty with verification, make sure you entered the correct port and cable modem
card slot number when you activated ARP and when you entered the
show interface cable command.
Activating Host-to-Host Communication (Proxy ARP)
Cable proxy ARP allows the Cisco uBR7100 series CMTS to issue cable ARP requests on behalf of
cable modems on the same cable network subnet.
Note
Because the downstream and upstreams are separate interfaces, modems cannot directly perform ARP
with other modems on the cable plant.
Note
The default values for the commands used in this configuration task are adequate in most cases to
configure the Cisco uBR7100 series CMTS.
Activating Cable Proxy ARP Requests
To activate cable proxy ARP for host-to-host communications, use the following command in cable
interface configuration mode.
Table 3-2
Instructions to Activate Cable Proxy ARP Requests
Command
Purpose
CMTS01(config-if)# cable proxy-arp
Enable proxy ARP on the cable interface. This is the default.
Verifying Cable Proxy ARP Requests
To verify if cable proxy ARP has been activated or deactivated, enter the more system:running-config
and look for the cable interface configuration information. If cable proxy ARP has been activated, it does
not appear in the output. If cable proxy ARP has been deactivated, it appears in the output as no cable
proxy-arp.
CMTS01# more system:running-config
Building configuration...
Current configuration:
!
interface Cable1/0
ip address 1.1.1.1 255.255.255.0
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no keepalive
no cable proxy-arp
cable downstream annex B
cable downstream modulation 64qam
cable downstream interleave-depth 32
cable downstream symbol-rate 5056941
cable upstream 0 frequency 15008000
no cable upstream 0 shutdown
Tip
If you are having difficulty with verification, make sure you entered the correct port and cable modem
card slot number when you activated cable proxy ARP.
Configuring DHCP Options
Activating Cable Relay Agent
The cable relay agent is for use with DOCSIS-based DHCP servers that utilize option 82 to automatically
map the Ethernet MAC address of a host (subscriber PC) with the cable interface to which it is
connected.
With the cable relay agent activated, the Cisco uBR7100 series CMTS inserts the cable interface MAC
address into a DHCP packet when the packet is received from a cable interface or another host. The
Cisco uBR7100 series CMTS then forwards the packet to the DHCP server.
To activate the cable relay agent, use the following command in cable interface configuration mode.
Command
Purpose
CMTS01(config)# cable relay-agent-option
Activate the cable relay agent. This is the default.
Tip
If you are having difficulty with verification, make sure you entered the correct port and cable interface
card slot number when you activated the cable relay-agent-option.
Note
A DOCSIS-based DHCP server is required. The DHCP server verifies that the defined IP address, if any,
returned to the host is valid for the IP subnet on that downstream interface. The IP address must be
unique and valid in the subnet for the subscriber to obtain connectivity.
Activating DHCP giaddr
Configure the Cisco uBR7100 series CMTS so it will either assign primary addresses to cable modems
and remote hosts, or assign primary addresses to cable modems and secondary addresses to remote hosts.
To configure cable DHCP giaddr functionality, use one of the following commands in cable interface
configuration mode.
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Configuring Time-of-Day Service
Command
Purpose
CMTS01(config)# cable dhcp-giaddr primary
Enable cable DHCP giaddr functionality so
that primary addresses are assigned to both
cable modems and remote hosts.
or
CMTS01(config-if)# cable dhcp-giaddr policy
Enable cable DHCP giaddr functionality so
that primary addresses are assigned to cable
modems and secondary addresses are
assigned to remote hosts.
To disable cable DHCP giaddr functionality (the default) after it has been enabled, enter the no cable
dhcp-giaddr command in cable interface configuration mode.
Verifying DHCP giaddr Activation
To determine if DHCP giaddr is activated, enter the show running-config command and look for the
cable interface configuration information. If DHCP giaddr is activated, a notation appears in this output.
If DHCP giaddr is deactivated, no entry appears in this output.
Configuring Time-of-Day Service
Activating Time-of-Day Service
To activate Time-of-Day (ToD) service for the Cisco uBR7100 series CMTS, use the following
command in global configuration mode.
Command
Purpose
CMTS01(config)# cable time-server enable
Enable Time-of-Day (ToD) service for the
Cisco uBR7100 series CMTS
To disable ToD service (the default) after it has been enabled, enter the no cable time-server command
or the cable time-server disable command in global configuration mode.
Verifying Time-of-Day Service
To determine if ToD service is activated, enter the show running-config command and look for the
global cable configuration information. If ToD service is activated, an entry appears in this output. If
ToD service is deactivated, no entry appears in this output.
Setting Optional IP Parameters
You can set additional IP parameters to enable downstream echoing of upstream data. To configure these
optional IP parameters, perform the following tasks:
•
“Activating IP Multicast Echo” section on page 3-39
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•
Note
“Activating IP Broadcast Echo” section on page 3-39
The default values for the commands used in these configuration steps are adequate in most cases to
configure the Cisco uBR7100 series CMTS.
Activating IP Multicast Echo
The Cisco uBR7100 series CMTS echos IP multicast packets by default. To activate IP multicast echo if
it has been previously disabled, use the following command in cable interface configuration mode.
Command
Purpose
CMTS01(config-if)# cable ip-multicast-echo
Enable IP multicast echo. This is the default.
To disable IP multicast echo, enter the no cable ip-multicast-echo command in cable interface
configuration mode.
Verifying IP Multicast Echo
To determine if IP multicast echo is activated or deactivated, enter the more system:running-config
command and look for the cable interface configuration information. If IP multicast echo is activated,
there is no notation in the output, because this is the default setting. If IP multicast echo is deactivated,
a notation appears in the output:
CMTS01# more system:running-config
Building configuration...
Current configuration:
!
interface Cable1/0
ip address 1.1.1.1 255.255.255.0
no keepalive
no cable ip-multicast-echo
cable downstream annex B
cable downstream modulation 64qam
cable downstream interleave-depth 32
cable upstream 0 frequency 15008000
no cable upstream 0 shutdown
Tip
If you are having difficulty with verification, make sure that you have entered the correct slot and port
numbers when you entered cable interface configuration mode.
Activating IP Broadcast Echo
By default, the Cisco uBR7100 series CMTS does not echo IP broadcast packets. To activate IP
broadcast echo, use the following command in cable interface configuration mode.
Command
Purpose
CMTS01(config-if)# cable ip-broadcast-echo
Enable IP broadcast echo.
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Activating Packet Intercept Capabilities
To disable IP broadcast echo when it is enabled, enter the no cable ip-broadcast-echo command in cable
interface configuration mode.
Verifying IP Broadcast Echo
To determine if IP broadcast echo is activated or deactivated, enter the more system:running-config
command, and look for a notation in the cable interface configuration information:
CMTS01# more system:running-config
Building configuration...
Current configuration:
!
interface Cable1/0
ip address 1.1.1.1 255.255.255.0
no keepalive
cable ip-broadcast-echo
cable downstream annex B
cable downstream modulation 64qam
cable downstream interleave-depth 32
cable upstream 0 frequency 15008000
no cable upstream 0 shutdown
Activating Packet Intercept Capabilities
To activate packet intercept functionality, use the following commands in cable interface configuration
mode.
Command
Purpose
CMTS01(config-if)# cable intercept
xxxx.xxxx.xxxx
Specify a MAC address on the cable network for which
interception capabilities are to be activated. A limit of 10
MACs exist.
CMTS01(config-if)# no cable intercept
xxxx.xxxx.xxxx
Disable interception after it is enabled.
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Configuring Cable Modulation Profiles
Configuring Cable Modulation Profiles
To configure cable profiles (deviating from defaults), perform the following as necessary:
•
“Configuring Cable Modulation Profiles” section on page 3-41
•
“Configuring QoS Profiles” section on page 3-43
•
“Setting QoS Permission” section on page 3-45
•
“Enforcing a QoS Profile Assignment” section on page 3-45 (Optional)
•
“Monitoring and Maintaining QoS for Higher Priority Traffic” section on page 3-47.
Configuring Cable Modulation Profiles
In this step, you are defining the elements used in a cable modulation profile. The Cisco uBR7100 series
CMTS supports as many as 8 cable modulation profiles. Profile 1 is the default.
Caution
If you modify a cable modulation profile from default parameters, you are changing the physical layer.
Changing physical layer characteristics affects router performance and function; therefore, only an
expert should perform this task.
The following modulation profile values are configurable:
•
Interval usage code (iuc)—Valid values are initial, long, reqdata, request, short, and station.
•
Fec-tbytes—The number of bytes that can be corrected per FEC codeword. Valid range is
0 to 10 bytes, where 0 means no FEC. This is the number of bytes that the FEC decoder can correct
within a codeword. A codeword consists of information bytes, called k-bytes and parity bytes for
error correction. The number of parity bytes is equal to two times the number of correctable error
(T). The size of T is dictated by channel impairments.
•
Fec-len—FEC codeword length. Valid range is 16 to 254 bits. This value enables an efficiency mode
wherein all codewords are fixed in size. In a fixed operation, all codewords are the same size with
the last codeword padded with nulls if there are not enough information bytes to fill it entirely. The
efficiency is gained by not having to transmit the nulls that pad the last codeword.
•
Burst-len—Maximum burst length in bytes. 0 means no limit on burst length. This is used to
determine the breakpoint between packets that use the short data grant burst profile and packets that
use the long data grant burst profile. If the required upstream time to transmit a packet is greater
than this value, the long data grant burst profile is used. If the time is less than or equal to this value,
the short data grant burst profile is used.
•
Guard-t—Guard time in symbols. This is the time between successive bursts. It is the blank time at
the end of a burst transmission that exists to ensure that one burst ends before another burst starts.
•
Mod—Modulation. Valid values are “16qam” and “qpsk”. Modulation type is used to select between
four bits per modulation symbol (QAM-16) or two bits per modulation symbol (QPSK). QAM-16
uses both phase and amplitude to carry information. QPSK carries information in the phase of the
signal carrier. QAM-16 requires approximately 7 dB higher C/N to achieve the same BER as QPSK,
but it transfers information at two times the rate of QPSK.
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Configuring Cable Modulation Profiles
•
Scrambler—Enable or disable scrambler. Valid values are scrambler and no-scrambler. Scrambler is
used to create an almost random sequence of transmission symbols, which ensures an even spectral
distribution of energy transmitted within the channel. The scrambler seed is an initial value that is
used to start the pseudo-randomizer to scramble the bits. Because both the transmitter and receiver
know the seed value, the scrambling can be reversed at the receiver, leaving only the original data.
•
Seed—Scrambler seed in hexadecimal format. Valid range is 0x0000 to 0x7FFF.
•
Diff—Enable or disable differential encoding. Valid values are diff and no-diff. Differential
encoding is a technique wherein the information is transmitted by the phase change between two
modulation symbols instead of by the absolute phase of a symbol. This technique makes the absolute
phase of the received signal insignificant and has the effect of doubling the BER for the same C/N.
•
Pre-len—Preamble length in bits. Valid range is 2 to 128 bits. Preamble length (and Preamble offset)
are used to define a synchronizing string of modulation symbols used to let the receiver find the
phase and timing of the transmitted burst.
•
Last-cw—Handling of FEC for last codeword. Valid values are fixed for fixed codeword length, and
shortened for shortened last code word.
•
Uw-len—Upstream unique word length. Enter uw8 for 8-bit unique words, or uw16 for 16-bit
unique code words.
To create or change a cable modulation profile, use the following command in global configuration
mode.
Command
Purpose
CMTS01(config)# cable modulation-profile profile iuc
Create a new cable modulation profile
fec-tbytes fec-len burst-len guard-t mod scrambler seed diff with a profile number or modify an
pre-len last-cw uw-len
existing profile.
In the following example, the request burst for cable modulation profile 2 is defined to have 0 fec-tbytes,
16 kbytes fec-len, a burst-len of 1, a guard time of 8, a mod value of qpsk, scrambler enabled with a seed
value of 152, differential encoding disabled, a preamble length of 64 bits, a fixed code word length, and
8-bit unique words for upstream unique word length.
CMTS01(config)# cable modulation-profile 2 request 0 16 1 8 qpsk scrambler 152 no-diff 64
fixed uw8
To remove a cable modulation profile, use the no cable modulation-profile profile command in global
configuration mode. You can use this command to remove all modulation profiles except for modulation
profile 1.
Tip
Entering no cable modulation-profile 1 sets all parameters in profile 1 to the default values.
Verifying Cable Modulation Profiles
To determine if a cable modulation profile is created, enter the show cable modulation-profile
command.
A sample output is shown in the following example:
CMTS01# show cable modulation-profile
Mo IUC
Type Preamb Diff FEC err FEC
length enco correct T
Scrambl Max
seed
B
bytes
Guard Last Scrambl Preamb
time CW
offset
size size
short
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Configuring Cable Modulation Profiles
1
1
1
1
request
initial
station
short
qpsk
qpsk
qpsk
qpsk
64
128
128
72
no
no
no
no
0x0
0x5
0x5
0x5
0x10
0x22
0x22
0x4B
0x152
0x152
0x152
0x152
1
0
0
0
8
48
48
8
no
no
no
no
yes
yes
yes
yes
56
0
0
48
Note
If you have CBR scheduling parameters and IP precedence rate limits defined in the QoS profile, the
command output reveals this. Refer to the “Monitoring and Maintaining QoS for Higher Priority Traffic”
section on page 3-47. The show cable modulation-profile and show interface cable commands are
enhanced to reflect the state of the new MAC scheduler for the specified upstream port.
Tip
If you are having difficulty with verification, ensure that the system is in global configuration mode, and
that you typed the correct modulation profile number and elements when you entered the command.
The preamble offset is calculated from the modulation profile entries. The preamble offset is the distance
the CMTS looks into the preamble to determine where the preamble starts. The CMTS does not need to
look at the entire preamble in all instances. A shorter preamble has less overhead and time associated
with that type of burst request. In general, you should use an offset of “0” for initial/station maintenance
because you need to separate these packets as distinctly as possible.
The offset for QPSK is shorter because of the way DOCSIS specifies the preamble. For QPSK, it only
takes a preamble length of 256 bits to separate frames, whereas with QAM-16, the date rate is much
higher. Utilization of a larger preamble is necessary.
Configuring QoS Profiles
The Cisco uBR7100 series CMTS supports multiple QoS profiles. QoS profile 1 is used during
cable interface registration and QoS profile 2 is the default QoS profile. Both of these profiles are
preconfigured and cannot be removed. However, you can modify these profiles and create additional Q0S
profiles for various traffic flows.
To create or change a QoS profile, use the first command below, plus as many of the additional
commands as are necessary to make the changes you require. All of the QoS profile commands are global
configuration commands.
Command
Purpose
CMTS01(config)# cable qos-profile
groupnum
Create a new QoS profile with a profile number of
or modify an existing profile.
groupnum,
CMTS01(config)# cable qos-profile
groupnum ip-precedence bits
Set the bits in the Type of Service (ToS) byte that
enable you to configure individual data rate limits on
a per-modem basis. Valid values are from 0 to 7.
CMTS01(config)# cable qos-profile
groupnum guaranteed-upstream rate
Set the guaranteed minimum upstream rate in kbps.
Valid values are from 0 to 100000 kbps. Default = 0
(no reserved rate).
CMTS01(config)# cable qos-profile
groupnum max-burst size
Set the maximum upstream transmit burst size in
minislots that the cable modem can send for any
single transmit burst. Valid values are from 0 to 255
minislots. Default = 0 (no limit).
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Configuring Cable Modulation Profiles
Command
Purpose
CMTS01(config)# cable qos-profile
groupnum max-upstream rate
Set the maximum upstream data rate in kbps that a
cable modem using this QoS profile will send. Valid
values are from 0 to 100000 kbps. Default = 0 (no
upstream rate limit.)
CMTS01(config)# cable qos-profile
groupnum max-downstream rate
Set the maximum downstream data rate in kbps that
a cable modem using this QoS profile will receive.
Valid values are from 0 to 100000 kbps. Default = 0
(no downstream rate limit.)
CMTS01(config)# cable qos-profile
groupnum priority number
Assign a relative priority number for the upstream
traffic associated with this QoS profile. Valid values
are from 0 to 7, with 7 being the highest priority.
Default = 0.
CMTS01(config)# cable qos-profile
groupnum tos-overwrite value
Overwrite the ToS byte in the IP datagrams received
on the upstream before forwarding them
downstream. Set the mask bits to a hexadecimal
value to help the CMTS identify datagrams for QoS
on the backbone.
Note
You can use a single cable qos-profile command to configure multiple parameters for the selected QoS
profile number.
Tip
Use the no cable qos-profile groupnum command to remove an optional QoS profile, or in the case of
QoS profiles 1 and 2, to return the parameters to their default values.
Verifying QoS Profiles
To determine if a QoS profile has been created, and to see how it is configured, enter the
show cable qos profile command:
CMTS01# show cable qos profile
Service Prio Max
Guarantee
class
upstream upstream
bandwidth bandwidth
1
0
0
0
2
0
64000
0
3
0
3120
31200
no
4
7
87200
87200
yes
5
0
0x0 0x0
cm
no
yes
Max
downstream
bandwidth
0
1000000
0
Max tx TOS TOS
Create
burst mask value by
0
0
0x0
0x0
0
0x0
0x0
0
0
256000
cmts
cmts
0x0
0x0
128000
0x0
0x0
B
priv
enab
no
no
cmts
IP
prec
enab
no
no
yes
cmts
1000000
yes
0
Tip
If you are having difficulty with verification, make sure you typed the correct QoS profile number and
profile elements when you entered the command in global configuration mode.
Note
Cable modems that register continuously and fail consume more resources than cable interfaces that stay
registered. Assign customers who do not pay for service to QoS profile 3.
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Caution
DOCSIS 1.0-certified cable interfaces that are given a short max-burst size might be unable to transmit
large packets to the headend.
Setting QoS Permission
The Cisco uBR7100 series CMTS supports the creation of QoS table entries by SNMP or by CM
registration requests. You can also configure a Cisco uBR7100 series CMTS to dynamically update QoS
table entries via SNMP.
To set QoS table access, use one or more of the following commands in global configuration mode.
Command
Purpose
CMTS01(config)#
cable qos permission create-snmp
Enable SNMP access to create entries in the
QoS tables.
CMTS01(config)#
cable qos permission update-snmp Enable SNMP access to dynamically update
entries in the QoS tables.
CMTS01(config)#
cable qos permission modems
Enable QoS table entries to be created using
a CM registration requests.
CMTS01(config)#
no cable qos permission
Disable both SNMP access and CM
registration access to the QoS tables.
Verifying QoS Permission
To verify QoS permissions, enter the show cable qos permission command:
CMTS01# show cable qos permission
Create by SNMP Update by SNMP Create by modems
no
no
yes
Tip
If you are having difficulty with verification, make sure you typed the correct QoS profile number and
profile elements in global configuration mode.
Note
QoS profiles can be changed dynamically, permitting service tiers that are time-sensitive. This provides
more bandwidth during business hours than on weekends for telecommuter applications.
Enforcing a QoS Profile Assignment
To override the provisioned QoS profile of a CM and enforce a CMTS-specified QoS profile, use the
following command in global configuration mode.
Command
Purpose
CMTS01(config)# cable qos permission enforce
index
Assigns the QoS profile, specified by the
index number, to all CMs attempting to
connect to theCisco uBR7100 series
CMTS.
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Setting Quality of Service (QoS) for Higher Priority Traffic
Verifying a QoS Profile Assignment
Step 1
Load the Cisco uBR7100 series CMTS and wait for the CMs to come online as indicated by the
show cable modem command.
Notice that the CMs are getting their provisioned class of service as indicated by the
show cable modem and show cable qos profile commands.
Step 2
Configure any QoS profile at the CMTS with a specific index number (for example index 1) by using the
SNMP/CLI.
Step 3
Enter the global command cable qos permission enforce 1.
Step 4
Enter the clear cable modem all reset global configuration command to force the CMs to reregister with
the CMTS.
Notice that the CMs are assigned temporarily the CMTS-defined PRE_REGISTRATION QoS profile
with index 2 until the CMs register with the CMTS.
Step 5
Use the debug cable reg command to see that the provisioned QoS parameters of the CMs are
overwritten at the CMTS during registration. Notice that at the end of the registration, the CM gets the
user-enforced QoS profile as indicated by the show cable modem and show cable qos profile
commands.
Setting Quality of Service (QoS) for Higher Priority Traffic
This feature describes the software enhancements and procedures that support QoS for higher priority
traffic. These enhancements include improved support for:
•
Delay/jitter requirements of higher priority traffic
•
Increase in per-modem data throughput
•
New MAC scheduler
•
MAC messaging enhancements to better support real time responses to high priority service requests
Refer to the following procedures for setting QoS for higher priority traffic:
•
“Configuring a QoS Profile for Higher Priority Traffic” section on page 3-46
•
“Monitoring and Maintaining QoS for Higher Priority Traffic” section on page 3-47
Configuring a QoS Profile for Higher Priority Traffic
Perform these steps to configure a QoS modulation profile:
Command
Purpose
Step 1
Router(config)# cable qos-profile n name
Assigns a name to the QoS profile.
Step 2
Router(config)# cable qos-profile n priority
Sets the upstream traffic priority.
Step 3
Router(config)# qos-profile n max-upstream
Sets the maximum upstream traffic rate.
Step 4
Router(config)# qos-profile n guaranteed-upstream
Sets the guaranteed upstream traffic rate.
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Command
Purpose
Step 5
Router(config)# qos-profile n grant-size
Sets the size for unsolicited grants.
Step 6
Router(config)# qos-profile n grant-interval
Sets the interval for unsolicited grants.
Step 7
Router(config)# qos-profile n max-burst
Sets the maximum rate for upstream transmission bursts.
Step 8
Router(config)# qos-profile
n ToS-overwrite
Sets the mask bits to overwrite the Type of Service byte.
Step 9
Router(config)# qos-profile
n max-downstream
Sets the maximum downstream traffic rate.
Step 10
Router(config)# qos-profile
n privacy
Enables baseline privacy.
Step 11
Router(config)# qos-profile
n ip-precedence
Downstream settings are based on IP precedence.
Monitoring and Maintaining QoS for Higher Priority Traffic
Use the following commands to monitor and maintain QoS for higher priority traffic.
Command
Purpose
Router# show cable qos profile n
Displays the configuration for the specified
profile.
Router# show interface cable x/y sid
Displays each QoS profile configured for the
specified cable interface.
Router# show interface cable x/y upstream
Displays QoS statistics for the upstream channel.
The following example shows how the cable router (mgmt) creates a CM with a QoS profile 30:
Router(config)#
Router(config)#
Router(config)#
Router(config)#
Router(config)#
Router(config)#
Router(config)#
Router(config)#
Router(config)#
Router(config)#
cable
cable
cable
cable
cable
cable
cable
cable
cable
cable
qos
qos
qos
qos
qos
qos
qos
qos
qos
qos
profile
profile
profile
profile
profile
profile
profile
profile
profile
profile
30
30
30
30
30
30
30
30
30
30
name qostest
grant-int 55
grant-size 100
guaranteed 60000
ip-prec 7
max-bur 256
max-down 3000
max-up 6000
prior 7
privacy
router# show cable qos profile 30
ID Prio Max
Guarantee Max
upstream upstream downstream
bandwidth bandwidth bandwidth
30 7
6000000
60000000 100000000
Max
ToS ToS
Create
tx
mask value by
burst
256
0x0 0x0
mgmt
B
priv
enab
yes
IP prec.
rate
enab
no
To configure a QoS profile, enter the cable qos profile global configuration command. To set default
values for profile group numbers 1 or 2, or to remove the QoS profile if no specific parameters remain,
enter the no form of this command.
cable qos profile {groupnum | grant-interval {interval}| grant-size {size} |
guaranteed-upstream {rate} | ip-precedence {value} | max-burst {rate} | max-downstream
{rate} | max-upstream {rate} | name {string} | priority {value} | privacy | ToS-overwrite
{value}}
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no cable qos profile {groupnum | grant-interval {interval} | grant-size {size} |
guaranteed-upstream {rate} | ip-precedence {value} | max-burst {rate} | max-downstream
{rate} | max-upstream {rate} | name {string} | priority {value} | privacy | ToS-overwrite
{value}}
The following table describes the syntax and values for these commands.
Syntax
Valid Values
groupnum
QoS profile group number. Qos profiles 1 and 2 are required by the
system. QoS profile 1 is used during registration, and QoS profile 2 is
the default QoS profile. Both profiles are preconfigured and cannot be
removed. However, you can modify these profiles.
grant-interval
The periodic interval in microseconds at which the CM wants to send
the fixed-sized upstream MAC frames. This value is used to compute
the period between constant bit rate (CBR) slots for the CM. Valid range
is 0 to 65535.
grant-size
The size of the DOCSIS MAC frame the CM wants periodically to send
on the upstream transmission. This value in bytes does not include any
PHY layer overhead. It includes the complete fixed MAC frame size
starting from the frame control byte to the CRC of the protocol data unit
(PDU). This parameter is used by the CMTS to set the size of the
periodic CBR slot for the CM after adding the PHY overhead.
guaranteed-upstream
Guaranteed minimum upstream rate in kilobytes per second. Valid
values are 0 through 100000. Default value is 0 (no reserved rate).
ip-precedence
Bits in the ToS byte that enable you to configure individual data rate
limits on a per modem basis. Valid values are 0 to 7.
max-burst
Maximum upstream transmit burst size in bytes that the modem can
send for any single transmit burst. Valid values are 0 to 65535 bytes.
Default value is 0 (no limit).
max-downstream
Maximum downstream data rate in kilobytes per second that a modem
using this QoS profile receives. Valid values are 0 to 100000. Default
value is 0 (no downstream rate limit).
max-upstream
Maximum upstream data rate in kilobytes per second that a modem
using this QoS profile receives. Valid values are 0 to 255. Default value
is 0 (no upstream rate limit).
name
QoS name string.
priority
Relative priority number assigned to upstream traffic by this QoS
profile. Valid values are 0 to 7, with 7 being the highest priority. Default
value is 0.
privacy
Enables cable baseline privacy.
ToS-overwrite
Overwrite the ToS field in the IP datagrams received on the upstream
before forwarding them downstream (or IP backbone). This parameter
sets the hexadecimal mask bits to a hexadecimal value, thereby helping
the CMTS identify datagrams for QoS on the backbone. Valid range is
0x0 to 0xFF.
value
The value substituted for the ToS value. See ToS-overwrite.
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Refer to the following example to configure QoS profile 4 with guaranteed upstream of 2 kbps,
maximum transmission burst of 2, an IP precedence of 7, a maximum downstream rate of 300 kbps, with
a priority of 4, cable baseline privacy set, and a ToS-overwrite mask and value byte (in hex) of 0x7:
Router(config)#
Router(config)#
Router(config)#
Router(config)#
Router(config)#
Router(config)#
cable
cable
cable
cable
cable
cable
qos
qos
qos
qos
qos
qos
profile
profile
profile
profile
profile
profile
4
4
4
4
4
4
name Mondayqos
guaranteed-upstream 2
max-burst 2
ip-precedence 7 max-downstream 300
priority 4
ToS-overwrite 0x7
To display QoS profiles, use the show cable qos profile privileged EXEC configuration command.
Note
An optional “verbose” parameter is added:
show cable qos profile qos profile index verbose
The qos profile index option displays the index of the specified QoS profile. The verbose option displays
all details for the specified QoS profile index.
The following example shows the full QoS table for profile 30:
router# show cable qos profile 30 verbose
Profile Index
30
Name
test
Upstream Traffic Priority
7
Upstream Maximum Rate (bps)
6000000
Upstream Guaranteed Rate (bps)
60000000
Unsolicited Grant Size (bytes)
100
Unsolicited Grant Interval (usecs)
55000
Upstream Maximum Transmit Burst (bytes) 256
IP Type of Service Overwrite Mask
0x0
IP Type of Service Overwrite Value
0x0
Downstream Maximum Rate (bps)
100000000
Created By
mgmt
Baseline Privacy Enabled
yes
IP precedence rate limits
IP precedence
2
Rate Limit
100000
Table 3-2 describes the fields shown in the show cable qos profile displays.
Field
Description
Profile Index
Profile number.
Name
The name string for this profile.
Upstream Traffic Priority
Priority level for upstream traffic.
Upstream Maximum Rate (bps)
Maximum upstream transmission rate in bits per
second.
Upstream Guarantee Rate (bps)
Guaranteed minimum upstream rate in bits per second.
Unsolicited Grant Size (bytes)
Number of grant-size parameters in bytes. Grant size is
used by the CMTS to set the size of the periodic CBR
slot for the CM after adding the PHY overhead.
Unsolicited Grant Interval (usecs)
Number of unsolicited grant intervals in microseconds.
The grant-interval parameter is used to compute the
period between CBR slots for the CM.
Upstream Maximum Transmit Burst (bytes)
Maximum transmit burst size in bytes.
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Field
Description
IP Type of Service Overwrite Mask
Hex value of the mask bits.
IP Type of Service Overwrite Value
Value of the mask byte. This is the value the CMTS
will overwrite into the ToS field (after masking bits
specified in the ToS-mask parameter) of the IP
datagram before forwarding the datagram into IP
backbone/downstream. The IP ToS overwrite feature
helps to propagate cable access QoS onto the IP
backbone.
Downstream Maximum Rate (bps)
Minimum upstream transmission rate in bits per
second.
Created by
Identity of the profile creator.
Baseline Privacy Enabled
Reports yes if Baseline Privacy is enabled for this QoS
profile. Reports no if Baseline Privacy is not enabled
for this Qos profile.
IP Precedence rate limits
Value of the IP precedence and the transmission rate
limit in bits per second.
Table 3-3
Related Commands
Command
Description
cable qos permission
Sets permissions for updating QoS tables.
cable qos profile
Configures QoS profiles.
show cable qos permission
Displays the status of permissions for updating QoS tables.
In the sample show cable qos profile output response, note the added IP precedence column:
CMTS01# show cable qos
Service Prio Max
class
upstream
bandwidth
1
0
0
2
0
64000
3
0
3120
no
4
7
87200
yes
5
0x0 0x0
cm
profile
Guarantee
upstream
bandwidth
0
0
31200
Max
downstream
bandwidth
0
1000000
0
87200
Max tx TOS TOS
Create
burst mask value by
0
0
0x0
0x0
0
0
no
0x0
0x0
0
0
256000
yes
cmts
cmts
0x0
0x0
128000
0x0
0x0
B
priv
enab
no
no
cmts
IP
prec
enab
no
no
yes
cmts
1000000
yes
0
The software provides QoS based on the CM SID. Every QoS profile carries a parameter maximum
downstream rate which is used to provide peak rate limiting and traffic shaping on the downstream.
When the particular CM supports combined high priority and data traffic, rate exceeded data packets
might shut out or delay higher priority packets, degrading quality. As a solution, IP precedence bits are
used as a basic differentiator to provide independent rate limits for different traffic streams as desired.
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The show interface cable x/y upstream port # command is also enhanced to reflect the current state of
the new MAC scheduler for the specified upstream port as shown in the following example:
cmts# show interface cable 1/0 upstream 0
Cable1/0: Upstream 0 is up
Received 68 broadcasts, 0 multicasts, 20811 unicasts
0 discards, 99 errors, 0 unknown protocol
20879 packets input, 0 corrected, 0 uncorrectable
99 noise, 0 microreflections
Total Modems On This Upstream Channel : 2 (2 active)
Default MAC scheduler
Queue[Cont Mslots] 1/104, fifo queuing, 0 drops
Queue[Rng Polls] 0/20, fifo queuing, 0 drops
Queue[CIR Grants] 0/20, fair queuing, 0 drops
Queue[BE Grants] 0/30, fair queuing, 0 drops
Queue[Grant Shpr]
0/30, calendar queuing, 0 drops
Reserved slot table currently has 5 CBR entries
Req IEs 176103, Req/Data IEs 0
Init Mtn IEs 540, Stn Mtn IEs 101
Long Grant IEs 10042, Short Grant IEs 405
Total channel bw reserved 200000 bps
CIR admission control not enforced
Current minislot count
: 2099853
Flag: 1
Scheduled minislot count : 2100020
Flag: 1
The show interface sid command is also enhanced to display the type of SID—whether it is “Static”
versus “Dynamic”.
cmts# show interface cable x/y sid
Sid
Prim
Sid
2
4
2
Type Online
State
Admin
Status
QoS
Create
Time
IP Address MAC Address
stat
online
enable
4
12:10:25
1.11.51.37 0010.7b6b.722d
dyn
online
enable
5
12:10:30
1.11.51.37 0010.7b6b.722d
You can optimize the physical layer parameters on an upstream channel. An example is provided for
physical layer parameters that can be used on the CMTS for upstream channels expected to support high
priority traffic density. These parameters minimize the physical layer overhead encountered for each
fixed sized (89 bytes) packet. The resulting fine tuning gives a direct improvement in the number of CBR
high priority connections that can be admitted on a single upstream channel.
Configure the following settings for the upstream channel to maximize the number of CBR
connections:
•
Minislot size: 8
•
Symbol rate: 1280 Ksymbols/sec
•
Modulation type: QPSK
•
Preamble length: 72 bits
•
FEC (T bytes): 2 bytes
•
FEC codeword length: 52 bytes
•
Guard time: 8 symbols
•
Last codeword: shortened last codeword
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Setting and Viewing Concatenation
To configure the above modulation profile at the CMTS, use the following commands:
Create a new qpsk modulation profile template m with all default parameters, except the “short grant”
profile which has special parameters as given below:
cmts(config)# cable modulation-profile m qpsk
cmts(config)# cable modulation-profile m short 2 52 16 8 qpsk scrambler 152 diff 72
shortened uw8
Configure upstream port n on a given interface to use minislot size of 8 ticks and above modulation
profile template m:
cmts(config-if)# cable upstream n minislot-size 8
cmts(config-if)# cable upstream n modulation-profile m
Setting and Viewing Concatenation
To turn concatenation off or on from the CMTS, use the cable upstream concatenation interface
configuration command. To turn off concatenation from the default state of on, use the no form of this
command.
cable upstream n concatenation
no cable upstream n concatenation
Note
Concatenation is part of DOCSIS 1.0 extension support. Concatenation must be supported at both the
CMTS and the CM. When enabled on both the CMTS and the CM, the CMTS can receive a concatenated
burst of multiple MAC frames from the CM.
Setting Concatenation
Command
Purpose
Step 1
Router(config-if)# no cable upstream n concatenation
Turns off concatenation on the specified channel.
Step 2
Router(config-if)# cable upstream n concatenation
Turns on concatenation on the specified channel.
Tip
Caution
Concatenation is enabled by default.
Turning off concatenation instructs the CM that the CMTS does not want the CM to concatenate. It is
actually up to the CM not to concatenate. If the CM concatenates even after the no cable upstream
number concatenation interface command is issued, the CM might concatenate incorrectly. Such a CM
is considered noncompliant.
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Setting and Viewing Concatenation
Viewing Concatenation Status
Use the following command to monitor concatenation:
Command
Purpose
Router# show controller cable slot/port
Displays the current status of concatenation for the
specified slot and port.
The following display indicates that concatenation is turned off.
Lab-CMTS# show controller cab 1/0
Interface Cable1/0
Hardware is BCM3210 FPGA
idb 0x6182BE18 MAC regs 0x3D900000 PLX regs 0x3D800000
rx ring entries 1024 tx ring entries 128 MAP tx ring entries 128
Rx ring 0x4B09A400 shadow 0x61849408 head 359
Tx ring 0x4B09C440 shadow 0x6184A478 head 85 tail 85 count 0
MAP Tx ring 0x4B09C880 shadow 0x6184A8E8 head 7 tail 7 count 0
MAP timer sourced from slot 4
throttled 0 enabled 0 disabled 0
Rx: spurious 341 framing_err 0 hcs_err 2 no_buffer 0 short_pkt 2
no_enqueue 0 no_enp 1 miss_count 0 latency 16
invalid_sid 0 invalid_mac 0 bad_ext_hdr_pdu 0 concat 0 bad-concat 0
Tx: full 0 drop 0 stuck 0 latency 1
MTx: full 0 drop 0 stuck 0 latency 9
Slots 68056 NoUWCollNoEngy 15 FECorHCS 2 HCS 0
Req 1803579865 ReqColl 1 ReqNoise 276120 ReqNoEnergy 0
ReqData 0 ReqDataColl 0 ReqDataNoise 0 ReqDataNoEnergy 0
Rng 143099 RngColl 0 RngNoise 3891
FECBlks 0 UnCorFECBlks 0 CorFECBlks 0
MAP FIFO overflow 0, Rx FIFO overflow 0, No rx buf 0
DS FIFO overflow 0, US FIFO overflow 0, US stuck 0
Bandwidth Requests= 0xFFC9
Piggyback Requests= 0xA1D
Ranging Requests= 0x22039
Timing Offset = 0x0
Bad bandwidth Requests= 0x31BC
No MAP buffer= 0x0
Cable1/0 Downstream is up
Frequency not set, Channel Width 6 MHz, 64-QAM, Symbol Rate 5.056941 Msps
FEC ITU-T J.83 Annex B, R/S Interleave I=32, J=4
Downstream channel ID: 0
Cable1/0 Upstream 0 is up
Frequency 20.208 MHz, Channel Width 1.600 MHz, QPSK Symbol Rate 1.280 Msps
Spectrum Group is overridden
SNR - Unknown
Nominal Input Power Level 0 dBmV, Tx Timing Offset 4667
Ranging Backoff automatic (Start 0, End 3)
Ranging Insertion Interval automatic (60 ms)
Tx Backoff Start 0, Tx Backoff End 4
Modulation Profile Group 1
concatenation is disabled
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Setting and Viewing Concatenation
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C H A P T E R
4
Configuring Basic Broadband Internet Access
This chapter describes the parameters of configuring and maintaining basic broadband Internet access.
The chapter contains these sections:
•
“Overview of Basic Broadband Internet Access” section on page 4-1
•
“Typical Routing Configuration For High Speed Internet Access” section on page 4-2
•
“Transparent Bridging Configuration” section on page 4-8
•
“Integrated Routing and Bridging Configuration” section on page 4-10
•
“Baseline Privacy Interface” section on page 4-13
Overview of Basic Broadband Internet Access
A Cisco uBR7100 series router and an intermediate frequency (IF)-to-RF upconverter are installed at the
headend or distribution hub to transmit digital data. The Cisco uBR7100 series router downstream ports
transmit IF signals to the upconverter, which translates the downstream signals to RF for broadcast.
Receivers, scramblers, and descramblers then process the TV signals to encode or decode signals as
needed for broadcast. Modulators format the analog TV and digital signals.
The analog and digital signals then pass through the RF combiner. The signals are broadcast from the
headend through optical transmitters to fiber nodes.
Amplifiers, coaxial cable, and taps carry the signals to the subscriber premises. Signals are processed as
follows:
•
Tuners that handle MPEG video, audio and broadcast services in STBs, TVs, and VCRs receive
one-way analog signals.
•
CMs, or tuners in EuroDOCSIS STBs that handle IP data, receive digital data signals:
– Two-way CMs transmit RF signals back through amplifiers to optical fiber receivers at the
headend. These receivers pass the upstream signal to upstream ports on the Cisco uBR7100
series router where they are processed.
– Telco return CMs transmit over the PSTN. Refer to Telco Return for the Cisco CMTS for
additional information.
Figure 4-1 on page 4-2 illustrates this general signal flow and associated processes in the CMTS.
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Typical Routing Configuration For High Speed Internet Access
Figure 4-1
Two-Way Internet Access Network Example
Subscriber
cable modem
Headend / Hub
10BaseT
Off-air
channels
AM & digital
modulators
RF amplifiers
Optical transmitter
Satellite
channels
Receivers
Descramblers
Scramblers
Tap
RF
Optical node
Optical transmitter
Optical node
RF
RF
RF
Optical transmitter
Optical node
Upconverter RF
Downstream
RF
RF combiner
RF
IF
Note
Optical receiver
Upstream
37393
Internet
Cisco uBR7100
series
The external upconverter shown in Figure 4-1 is needed only if you are not using the router’s integrated
upconverter.
Typical Routing Configuration For High Speed Internet Access
When running in routing mode, the Cisco uBR7100 series router is fully capable of self provisioning all
cable modems and hosts to which it is attached. The router supports multiple IP subnets, including
different subnets for hosts and cable modems. Configuration options are only limited by available
configuration file length.
The Cisco uBR7100 series CMTS automatically connects DOCSIS-compliant cable modems and hosts
right out of the box. Therefore, the factory-supplied configuration activates the downstream RF to
851 MHz center frequency, and the upstream to 37 MHz.
Step 1
Note
Step 2
Connect one upstream and the downstream port to a duplex filter.
Do not combine multiple ports as they are all set on the same frequency.
Use at least 40 dB attenuation before the first modem, and modems will connect in under 5 minutes.
The following sample configuration file configures the Cisco uBR7111 router for typical routing
operation with the following features:
•
Basic DOCSIS Internet Access
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•
DHCP Address Pools—The Cisco uBR7111 router acts as a DHCP server, providing different
address spaces on the basis of the cable modem’s service level, including those customers whose
network access should be denied access because they have cancelled their service. Different default
pools can be used for cable modems and for the IP hosts behind them. Static IP addresses can also
be assigned to specific clients on the basis of the client’s MAC address.
•
DOCSIS Cable Modem Configuration Files—These configuration files provide several different
service level options:
– platinum.cm—Users are given a maximum upstream bandwidth of 128kbps, with a guaranteed
minimum bandwidth of 10kbps. The downstream has a maximum bandwidth of 10Mbps. Up to
8 PCs are allowed on this connection.
– gold.cm—Users are given a maximum upstream bandwidth of 64kbps and a maximum
downstream bandwidth of 5Mbps. Up to 3 PCs are allowed on this connection.
– silver.cm—Users are given a maximum upstream bandwidth of 64kbps and a maximum
downstream bandwidth of 1Mbps. Only 1 PC is allowed on this connection.
– disable.cm—Users are denied access to the cable network. This configuration file can be used
for users who have cancelled service or have not paid their bills.
!
version 12.1
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
service compress-config
service udp-small-servers max-servers 500
!
hostname ubr7100
!
boot system slot0:
!
no cable qos permission create
no cable qos permission update
cable qos permission modems
cable time-server
!
cable config-file platinum.cm
service-class 1 max-upstream 128
service-class 1 guaranteed-upstream 10
service-class 1 max-downstream 10000
service-class 1 max-burst 1600
cpe max 8
timestamp
!
cable config-file gold.cm
service-class 1 max-upstream 64
service-class 1 max-downstream 5000
service-class 1 max-burst 1600
cpe max 3
timestamp
!
cable config-file silver.cm
service-class 1 max-upstream 64
service-class 1 max-downstream 1000
service-class 1 max-burst 1600
cpe max 1
timestamp
!
cable config-file disable.cm
access-denied
service-class 1 max-upstream 1
service-class 1 max-downstream 1
service-class 1 max-burst 1600
cpe max 1
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timestamp
!
ip
ip
no
ip
ip
ip
!
ip
subnet-zero
cef
ip domain-lookup
dhcp excluded-address 10.128.1.1 10.128.1.15
dhcp excluded-address 10.254.1.1 10.254.1.15
dhcp ping packets 1
dhcp pool CableModems
network 10.128.1.0 255.255.255.0
bootfile platinum.cm
next-server 10.128.1.1
default-router 10.128.1.1
option 128 ip 10.128.1.1
option 4 ip 10.128.1.1
option 2 hex ffff.8f80
option 11 ip 10.128.1.1
option 10 ip 10.128.1.1
lease 1 0 10
!
ip dhcp pool hosts
network 10.254.1.0 255.255.255.0
next-server 10.254.1.1
default-router 10.254.1.1
dns-server 10.254.1.1 10.128.1.1
domain-name ExamplesDomainName.com
lease 1 0 10
!
ip dhcp pool staticPC(012)
host 10.254.1.12 255.255.255.0
client-identifier 0108.0009.af34.e2
client-name staticPC(012)
lease infinite
!
ip dhcp pool goldmodem
host 10.128.1.129 255.255.255.0
client-identifier 0100.1095.817f.66
bootfile gold.cm
!
ip dhcp pool DisabledModem(0010.aaaa.0001)
host 10.128.1.9 255.255.255.0
client-identifier 0100.1095.817f.66
bootfile disable.cm
!
ip dhcp pool DisabledModem(0000.bbbb.0000)
client-identifier 0100.00bb.bb00.00
host 10.128.1.10 255.255.255.0
bootfile disable.cm
!
!
!
interface FastEthernet0/0
no ip address
no ip mroute-cache
shutdown
duplex auto
speed auto
!
interface FastEthernet0/1
no ip address
no ip mroute-cache
shutdown
duplex auto
speed auto
!
interface Cable1/0
description Cable Downstream Interface
ip address 10.254.1.1 255.255.255.0 secondary
ip address 10.128.1.1 255.255.255.0
no keepalive
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cable downstream annex B
cable downstream modulation 64qam
cable downstream interleave-depth 32
cable downstream frequency 851000000
cable down rf-power 55
cable upstream 0 description Cable upstream
cable upstream 0 frequency 37008000
cable upstream 0 power-level 0
cable upstream 0 admission-control 150
no cable upstream 0 shutdown
cable upstream 1 description Cable upstream
cable upstream 1 frequency 37008000
cable upstream 1 power-level 0
cable upstream 1 admission-control 150
no cable upstream 1 shutdown
cable upstream 2 description Cable upstream
cable upstream 2 frequency 37008000
cable upstream 2 power-level 0
cable upstream 2 admission-control 150
no cable upstream 2 shutdown
cable upstream 3 description Cable upstream
cable upstream 3 frequency 37008000
cable upstream 3 power-level 0
cable upstream 3 admission-control 150
no cable upstream 3 shutdown
no cable arp
cable source-verify dhcp
cable dhcp-giaddr policy
interface, North
interface, South
interface, East
interface, West
!
ip classless
no ip forward-protocol udp netbios-ns
ip route 0.0.0.0 0.0.0.0 FastEthernet0/0
no ip http server
!
!
alias exec scm show cable modem
alias exec scf show cable flap
alias exec scp show cable qos profile
!
line con 0
transport input none
line aux 0
line vty 0 4
login
!
end
To set up spectrum management in your configuration, use the following commands to set up the critical
elements:
cable spectrum-group 1 frequency 40000000
cable spectrum-group 1 frequency 20000000 2
In this illustration, the user has configured spectrum management group number “1” to be available to
upstream channels. As defined by the two previous command lines, the “preferred” choice is for the
upstream to operate on a 40-MHz channel. If that channel is not suitable for the transmission scheme
available, the upstream automatically moves over to transmitting at 20 MHz and increases the receive
power rating by 2 dB.
The command lines in the sample configuration file beginning with the string cable modulation-profile
contain the critical elements necessary to set up a modulation profile in your overall configuration:
cable
cable
cable
cable
cable
modulation-profile
modulation-profile
modulation-profile
modulation-profile
modulation-profile
3
3
3
3
3
request 0 16
initial 5 34
station 5 34
short 5 75 6
long 8 220 0
1
0
0
8
8
8 16qam scrambler 152 no-diff 128 fixed uw16
48 16qam scrambler 152 no-diff 256 fixed uw16
48 16qam scrambler 152 no-diff 256 fixed uw16
16qam scrambler 152 no-diff 144 fixed uw8
16qam scrambler 152 no-diff 160 fixed uw8
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EuroDOCSIS Operation
In this case, the user has configured modulation profile number “3” to be available to upstream channels
wherever they are configured to apply it. Note that this modulation profile has been configured to operate
with a QAM-16 modulation scheme. The default modulation scheme for any upstream profile (if it is not
set to QAM-16) is QPSK.
Later in the configuration file example, upstream port 0 on the cable interface card installed in slot 5
utilizes both the spectrum management and the modulation profile configured in the sample.
cable upstream 0 spectrum-group 1
cable upstream 0 modulation-profile 3
EuroDOCSIS Operation
The Cisco uBR7111E and Cisco uBR7114E routers support the EuroDOCSIS channel plans that use an
8 MHz channel width. Key commands that appear in the Cisco uBR7100 series configuration file that
denote EuroDOCSIS operation include:
•
cable downstream annex A—Annex A is reserved for EuroDOCSIS operations (Annex B is used
for DOCSIS NTSC operations). Annex A is chosen by default on the Cisco uBR7111E and
Cisco uBR7114E routers.
•
cable upstream 0 frequency—The EuroDOCSIS upstream valid range is from 5,000,000 to
65,000,000 Hz.
The following is a typical configuration file for EuroDOCSIS operation:
!
version 12.1
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname UBR7114
!
!
cable modulation-profile 1 request 0 16
no-diff 128 fixed uw16
cable modulation-profile 1 initial 5 34
no-diff 256 fixed uw16
cable modulation-profile 1 station 5 34
no-diff 256 fixed uw16
cable modulation-profile 1 short 6 75 6
144 fixeduw8
cable modulation-profile 1 long 8 220 0
160 fixeduw8
cable modulation-profile 2 request 0 16
64 fixeduw8
cable modulation-profile 2 initial 5 34
no-diff 128 fixed uw16
cable modulation-profile 2 station 5 34
no-diff 128 fixed uw16
cable modulation-profile 2 short 5 75 6
72 fixed uw8
cable modulation-profile 2 long 8 220 0
80 fixed uw8
!
no cable qos permission create
no cable qos permission update
cable qos permission modems
!
1 8 16qam scrambler 152
0 48 16qam scrambler 152
0 48 16qam scrambler 152
8 16qam scrambler 152 no-diff
8 16qam scrambler 152 no-diff
1 8 qpsk scrambler 152 no-diff
0 48 qpsk scrambler 152
0 48 qpsk scrambler 152
8 qpsk scrambler 152 no-diff
8 qpsk scrambler 152 no-diff
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!
!
!
interface Loopback0
ip address 222.2.4.1 255.255.255.255
no ip directed-broadcast
!
interface Loopback2
ip address 111.0.4.2 255.255.255.255
no ip directed-broadcast
!
interface FastEthernet0/0
ip address 1.8.93.9 255.255.0.0
no ip directed-broadcast
!
interface Cable1/0
ip address 3.214.1.1 255.255.255.0
no ip directed-broadcast
load-interval 30
no keepalive
cable spectrum-group 1
cable helper-address 1.8.93.100
cable downstream annex A
cable downstream modulation 64qam
cable downstream frequency 669000000
cable upstream 0 frequency 5008000
cable upstream 0 power-level 0
no cable upstream 0 shutdown
cable upstream 1 frequency 10000000
cable upstream 1 power-level 0
no cable upstream 1 shutdown
cable upstream 2 frequency 15008000
cable upstream 2 power-level 0
no cable upstream 2 shutdown
cable upstream 3 frequency 20000000
cable upstream 3 power-level 0
no cable upstream 3 shutdown
!
ip default-gateway 1.8.0.1
ip classless
ip route 223.255.254.254 255.255.255.255 1.8.0.1
!
alias exec scm show cable modem
!
line con 0
exec-timeout 0 0
transport input none
line aux 0
line vty 0 4
password secret
login
!
end
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Transparent Bridging Configuration
Transparent Bridging Configuration
Bridging operation between the cable interface and port adapter interfaces is typically not used in
DOCSIS CMTS installations because of potential performance and security problems, but bridging
operations is appropriate for certain MDU/MTU applications. For example, a hotel could offer Internet
connectivity for customers who want to use a fixed IP address, as opposed to being assigned a temporary
IP address from the local server’s DHCP address pool.
Note
Transparent bridging is supported only when using Cisco IOS Release 12.1(7)EC or greater. For
complete details on transparent bridging and IRB operation, see the Bridging chapters in the Cisco IOS
Bridging and IBM Networking Configuration Guide, Release 12.1, available on CCO and the
Documentation CD-ROM.
The following sample configuration file configures the Cisco uBR7111 router for basic bridging
operation with the following features:
•
Basic DOCSIS Internet Access using bridging operations—This requires the following:
– IP routing is disabled.
– The FastEthernet and cable interfaces are assigned to the same bridge group.
– Each interface receives the same IP address since they form one logical network.
– The subscriber-loop-control bridging option is enabled on the cable interface to allow packets
received on an upstream to be forwarded to another cable modem host on the downstream.
Note
•
The spanning-tree protocol is disabled, by default, on the cable interface, but this is not
required.
DOCSIS Cable Modem Configuration Files—These configuration files provide several different
service level options:
– platinum.cm—Users are given a maximum upstream bandwidth of 128kbps, with a guaranteed
minimum bandwidth of 10kbps. The downstream has a maximum bandwidth of 10Mbps. Up to
8 PCs are allowed on this connection.
– gold.cm—Users are given a maximum upstream bandwidth of 64kbps and a maximum
downstream bandwidth of 5Mbps. Up to 3 PCs are allowed on this connection.
– silver.cm—Users are given a maximum upstream bandwidth of 64kbps and a maximum
downstream bandwidth of 1Mbps. Only 1 PC is allowed on this connection.
– disable.cm—Users are denied access to the cable network. This configuration file can be used
for users who have cancelled service or have not paid their bills.
•
TFTP server provides access to the cable modem configuration files (but a DHCP server is not
supported in bridging mode)
The following is a typical configuration file for transparent bridging operation:
!
version 12.1
no service pad
service timestamps debug datetime msec localtime
service timestamps log datetime
no service password-encryption
service udp-small-servers max-servers no-limit
service tcp-small-servers max-servers no-limit
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!
hostname ubr7100
!
no cable qos permission create
no cable qos permission update
cable qos permission modems
cable time-server
!
cable config-file platinum.cm
service-class 1 max-upstream 128
service-class 1 guaranteed-upstream 10
service-class 1 max-downstream 10000
service-class 1 max-burst 1600
cpe max 8
timestamp
!
cable config-file gold.cm
service-class 1 max-upstream 64
service-class 1 max-downstream 5000
service-class 1 max-burst 1600
cpe max 3
timestamp
!
cable config-file silver.cm
service-class 1 max-upstream 64
service-class 1 max-downstream 1000
service-class 1 max-burst 1600
cpe max 1
timestamp
!
cable config-file disable.cm
access-denied
service-class 1 max-upstream 1
service-class 1 max-downstream 1
service-class 1 max-burst 1600
cpe max 1
timestamp
!
!
clock timezone PST -9
clock calendar-valid
ip subnet-zero
no ip routing
no ip finger
no ip domain-lookup
!
interface FastEthernet0/0
ip address 10.1.1.1 255.255.255.0
no ip route-cache
no ip mroute-cache
no keepalive
duplex half
speed auto
no cdp enable
bridge-group 1
bridge-group 1 spanning-disabled
!
interface FastEthernet0/1
ip address 10.1.1.1 255.255.255.0
no ip route-cache
no ip mroute-cache
duplex auto
speed 10
no cdp enable
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bridge-group 1
bridge-group 1 spanning-disabled
!
interface Cable1/0
ip address 10.1.1.1 255.255.255.0
no ip route-cache
no ip mroute-cache
load-interval 30
no keepalive
cable downstream annex B
cable downstream modulation 256qam
cable downstream interleave-depth 32
cable downstream frequency 525000000
no cable downstream rf-shutdown
cable upstream 0 frequency 17808000
cable upstream 0 power-level 0
cable upstream 0 timing-adjust threshold 0
cable upstream 0 timing-adjust continue 0
cable upstream 0 channel-width 3200000
no cable upstream 0 shutdown
bridge-group 1
bridge-group 1 subscriber-loop-control
bridge-group 1 spanning-disabled
!
ip default-gateway 1.10.0.3
ip classless
no ip http server
!
no cdp run
tftp-server bootflash:platinum.cm alias platinum.cm
tftp-server bootflash:gold.cm alias gold.cm
tftp-server bootflash:silver.cm alias silver.cm
tftp-server bootflash:disable.cm alias disable.cm
!
line con 0
exec-timeout 0 0
privilege level 15
length 0
transport input none
line aux 0
line vty 0 4
privilege level 15
no login
!
end
Integrated Routing and Bridging Configuration
Integrated Routing and Bridging (IRB) operation allows bridging within a specific segment of networks
or hosts, yet also allows those hosts to connect to devices on other, routed networks, without having to
use a separate router to interconnect the two networks. IRB operation is typically not used in DOCSIS
CMTS installations because of potential performance and security problems, but bridging operations is
appropriate for certain MDU/MTU applications. For example, a hotel could offer Internet connectivity
for customers who want to use a fixed IP address, as opposed to being assigned a temporary IP address
from the local server’s DHCP address pool.
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Note
IRB operation is supported only when using Cisco IOS Release 12.1(7)EC or greater. For complete
details on transparent bridging and IRB operation, see the Bridging chapters in the Cisco IOS Bridging
and IBM Networking Configuration Guide, Release 12.1, available on CCO and the Documentation
CD-ROM.
The following sample configuration file configures the Cisco uBR7111 router for basic IRB operation
with the following features:
•
Basic DOCSIS Internet Access using IRB operations—This requires the following:
– IRB bridging is enabled.
– The FastEthernet and cable interfaces are assigned to the same bridge group.
– An IP address is configured only on the virtual BVI interface. No IP address is configured on
any physical interface.
– The subscriber-loop-control bridging option is enabled on the cable interface to allow packets
received on an upstream to be forwarded to another cable modem host on the downstream.
– The virtual BVI interface is configured with an IP address.
Note
•
The spanning-tree protocol is disabled, by default, on the cable interface, but this is not
required.
DOCSIS Cable Modem Configuration Files—These configuration files provide several different
service level options:
– platinum.cm—Users are given a maximum upstream bandwidth of 128kbps, with a guaranteed
minimum bandwidth of 10kbps. The downstream has a maximum bandwidth of 10Mbps. Up to
8 PCs are allowed on this connection.
– gold.cm—Users are given a maximum upstream bandwidth of 64kbps and a maximum
downstream bandwidth of 5Mbps. Up to 3 PCs are allowed on this connection.
– silver.cm—Users are given a maximum upstream bandwidth of 64kbps and a maximum
downstream bandwidth of 1Mbps. Only 1 PC is allowed on this connection.
– disable.cm—Users are denied access to the cable network. This configuration file can be used
for users who have cancelled service or have not paid their bills.
•
TFTP server provides access to the cable modem configuration files (but a DHCP server is not
supported in bridging mode)
The following is a typical configuration file for IRB operation:
!
version 12.1
no service pad
service timestamps debug datetime msec localtime
service timestamps log datetime
no service password-encryption
service udp-small-servers max-servers no-limit
service tcp-small-servers max-servers no-limit
!
hostname ubr7100
!
logging buffered 409600 debugging
no logging console
!
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no cable qos permission create
no cable qos permission update
cable qos permission modems
cable time-server
!
cable config-file platinum.cm
service-class 1 max-upstream 128
service-class 1 guaranteed-upstream 10
service-class 1 max-downstream 10000
service-class 1 max-burst 1600
cpe max 8
timestamp
!
cable config-file gold.cm
service-class 1 max-upstream 64
service-class 1 max-downstream 5000
service-class 1 max-burst 1600
cpe max 3
timestamp
!
cable config-file silver.cm
service-class 1 max-upstream 64
service-class 1 max-downstream 1000
service-class 1 max-burst 1600
cpe max 1
timestamp
!
cable config-file disable.cm
access-denied
service-class 1 max-upstream 1
service-class 1 max-downstream 1
service-class 1 max-burst 1600
cpe max 1
timestamp
!
!
clock timezone PST -9
clock calendar-valid
ip subnet-zero
no ip finger
no ip domain-lookup
!
bridge irb
!
interface FastEthernet0/0
no ip address
no ip mroute-cache
no keepalive
duplex half
speed auto
no cdp enable
bridge-group 1
bridge-group 1 spanning-disabled
!
interface FastEthernet0/1
no ip address
no ip mroute-cache
duplex auto
speed 10
no cdp enable
bridge-group 1
bridge-group 1 spanning-disabled
!
interface Cable1/0
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no ip address
no ip mroute-cache
load-interval 30
no keepalive
cable downstream annex B
cable downstream modulation 256qam
cable downstream interleave-depth 32
cable downstream frequency 525000000
no cable downstream rf-shutdown
cable upstream 0 frequency 17808000
cable upstream 0 power-level 0
cable upstream 0 timing-adjust threshold 0
cable upstream 0 timing-adjust continue 0
cable upstream 0 channel-width 3200000
no cable upstream 0 shutdown
bridge-group 1
bridge-group 1 subscriber-loop-control
bridge-group 1 spanning-disabled
!
interface BVI1
ip address 100.1.1.1 255.255.255.0
!
ip default-gateway 1.10.0.3
ip classless
no ip http server
!
no cdp run
tftp-server bootflash:platinum.cm alias platinum.cm
tftp-server bootflash:gold.cm alias gold.cm
tftp-server bootflash:silver.cm alias silver.cm
tftp-server bootflash:disable.cm alias disable.cm
bridge 1 protocol ieee
bridge 1 route ip
alias exec scm show cable modem
alias exec sib show ip int brief
!
line con 0
exec-timeout 0 0
privilege level 15
length 0
transport input none
line aux 0
line vty 0 4
privilege level 15
no login
!
end
Baseline Privacy Interface
The Cisco uBR7100 series CMTS supports 56-bit and 40-bit encryption/decryption; 56 bit is the default.
After you choose a CMTS image that supports BPI, BPI is enabled by default for the Cisco uBR7100
series routers.
When baseline privacy is enabled, the Cisco uBR7100 series router routes encrypted/decrypted packets
from a host or peer to another host or peer. BPI is configured with Key Encryption Keys (KEKs) and
traffic encryption keys (TEKs). A KEK is assigned to a cable modem based on the cable modem’s service
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identifier (SID), and permits the cable modem to connect to the Cisco uBR7100 series router when
baseline privacy is activated. The TEK is assigned to a cable modem when its KEK has been established.
The TEK is used to encrypt data traffic between the cable modem and the Cisco uBR7100 series CMTS.
Keks and TEKs can be set to expire based on a gracetime or a lifetime value. A gracetime key is used to
assign a temporary key to a cable modem to access the network. A lifetime key is used to assign a more
permanent key to a cable modem. Each cable modem that has a lifetime key assigned will request a new
lifetime key from the Cisco uBR7100 series CMTS before the current one expires.
Tip
Use the show cable modem command to identify a cable modem with encryption/decryption enabled.
The online(pk) output of this command reveals a cable modem that is registered with BPI enabled and a
KEK assigned. The online(pt) output reveals a cable modem that is registered with BPI enabled and a
TEK assigned.
Commands that enable, disable, and configure BPI encryption/decryption include:
•
cable privacy kek grace-time 800
•
cable privacy kek life-time 750000
•
cable privacy tek grace-time 800
•
cable privacy tek life-time 56000
•
cable privacy enable
•
cable privacy mandatory
To change the Cisco uBR7100 series default of 56-bit encryption/decryption to 40-bit, use the “40 bit
des” option:
CMTS(config-if)# cable
40-bit-des
^^^^^^^^^^
authenticate-modem
authorize-multicast
kek
mandatory
tek
privacy ?
select 40 bit DES
turn on BPI modem authentication
turn on BPI multicast authorization
KEK Key Parms
force privacy be mandatory
TEK Key Parms
Software then generates a 40-bit DES key, where the DES key that is generated and returned masks the
first 16-bits of the 56-bit key to zero in software. To return to 56-bit encryption/decryption after changing
to 40-bit, enter the no command in front of the “40 bit des” option.
Caution
Cisco uBR7100 series telco return images that support BPI do not support encryption/decryption in the
telco return path.
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Troubleshooting the System
This chapter contains troubleshooting information for various functions of your Cisco uBR7100 series
CMTS, and includes the following sections:
•
“Using a Cable Modem at the Headend to Verify Downstream Signals” section on page 5-1
•
“Managing Cable Modems on the HFC Network” section on page 5-2
•
“Polling Cable Modems” section on page 5-15
•
“Understanding Show Command Responses” section on page 5-17
•
“Troubleshooting Cable Flap Lists” section on page 5-31
•
“Performing Amplitude Averaging” section on page 5-42
•
“Setting Downstream Test Signals” section on page 5-44
•
“Pinging Unresponsive Cable Modems” section on page 5-46
•
“Using the Cable Monitor Feature” section on page 5-46
•
“Using Cable Interface debug Commands” section on page 5-48
Using a Cable Modem at the Headend to Verify Downstream
Signals
You can use a Cisco uBR924 cable access router to verify the downstream signal originating from a
Cisco uBR7100 series universal broadband router. Be sure you configure the Cisco uBR924 according
to DOCSIS cable modem practices. To verify the downstream signal from a Cisco uBR7100 series
universal broadband router using a Cisco uBR924, follow the procedure below:
Step 1
After the Cisco uBR924 is operational and you have an input signal between 0 and +5 dBmV, enter the
show controller c0 tuner command.
Step 2
Scan the output for the value corresponding to the signal to noise (SNR) estimate variable. If this value
is at least 35 dB, you have an optimized signal. If the value is less than 34 dB, adjust the upconverter at
the cable headend.
Tip
The SNR estimate for a cable modem installed at a headend should be between 35 and 39 dB. Although
the exact value displayed will vary from cable modem to cable modem, values collected on the same
cable modem from measurement to measurement will be consistent. Maximizing SNR optimizes cable
modem reliability and service quality.
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Managing Cable Modems on the HFC Network
To manage cable modems connected to the network, perform the following tasks as appropriate:
Caution
•
“Configuring Sync Message Interval” section on page 5-2
•
“Activating Cable Modem Authentication” section on page 5-3
•
“Activating Cable Modem Upstream Address Verification” section on page 5-3
•
“Configuring Dynamic Contention Algorithms (Cable Insertion Interval, Range, and Data
Backoffs)” section on page 5-4
•
“Configuring the Dynamic Map Advance Algorithm” section on page 5-5
•
“Configuring Per Modem Filters” section on page 5-6
•
“Configuring the Maximum Number of Hosts Attached to a Cable Modem” section on page 5-7
•
“Configuring Cable Modem Registration Timeout” section on page 5-8
•
“Clearing Cable Modem Reset” section on page 5-8
•
“Clearing Cable Modem Counters” section on page 5-9
•
“Configuring Traffic Shaping” section on page 5-9
•
“Configuring Spectrum Management” section on page 5-11
Cisco recommends using default values for most commands. Default settings are adequate for most
systems.
Configuring Sync Message Interval
To specify the sync message interval between successive sync message transmissions from the
Cisco uBR7100 series CMTS, use the following command in cable interface configuration mode.
Command
Purpose
CMTS01(config-if)# cable sync-interval msec
Specify the interval in milliseconds between
successive sync message transmissions from the
Cisco uBR7100 series CMTS. Valid values are
from 1 to 200 msec. Default = 10 msec.
CMTS01(config-if)# no cable sync-interval
Return the sync message interval to its default
value of 10 msec.
Verifying Sync Message Interval
To determine if a sync message interval is configured, enter the show running-config command and
look for the cable interface configuration information. If the sync message interval is deactivated or reset
to its default value, the no sync interval command line appears in the output.
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Activating Cable Modem Authentication
The Cisco uBR7100 series CMTS can be configured to require all cable modems to return a known text
string to register with the CMTS and gain access to the network. The text string can be from 1 to 80
characters in length. To activate cable modem authentication, use the following command in cable
interface configuration mode.
Command
Purpose
CMTS01(config-if)# cable shared-secret [0|7]
authorization-key
Enable cable modem authentication:
CMTS01(config-if)# no cable shared-secret
Tip
•
0 specifies an unencrypted authentication key;
•
7
specifies an encrypted authentication key.
Disable cable modem authentication.
Be sure you enter the correct slot and port number in the cable interface configuration mode. Verify that
the cable modem is using BPI and that it is assigned to a QoS with privacy active. Verify that the cable
interface configuration file contains a matching key.
Verifying Cable Modem Authentication
To determine if cable modem authentication is activated or deactivated, enter the
more system:running-config command and look for the cable interface configuration information. If
cable modem authentication is deactivated, it appears in this output as no cable secret-shared.
Activating Cable Modem Upstream Address Verification
Cable modem upstream address verification ensures that only cable modems that have received DHCP
leases through the Cisco uBR7100 series CMTS can access the HFC network. The Cisco uBR7100 series
CMTS discards all packets received from or for hosts that have not received DHCP-assigned addresses.
To activate cable modem upstream address verification, use the following cable interface configuration
command.
Command
Purpose
CMTS01(config-if)# cable source-verify [dhcp]
Activate cable modem upstream verification.
The dhcp option specifies that queries be sent
to verify unknown IP addresses in upstream
data packets.
CMTS01(config-if)# no cable source-verify
Return to the default upstream verification
state.
Verifying Cable Modem Upstream Address Verification
To determine if cable modem upstream verification is activated or deactivated, enter the
more system:running-config command and look for the no cable source-verify notation in the
cable interface configuration information.
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Tip
Be sure you enter the correct slot and port number when you enter the cable interface configuration
mode.
Note
If the Cisco uBR7100 series router is reloaded or the ARP table is cleared, all hosts on the network will
be forced to release and renew their IP addresses. Some systems might require restarting if the
IP protocol stack is unable to renew using a broadcast IP address.
Configuring Dynamic Contention Algorithms (Cable Insertion Interval, Range,
and Data Backoffs)
The Cisco uBR7100 series software includes:
•
Algorithm that dynamically controls the rate of upstream contention slots —initial ranging and
bandwidth requests.
•
Algorithm that varies backoff parameters CMs use within each of the initial ranging and bandwidth
request upstream contention subchannels.
These algorithms control the capacity of the contention subchannel and how efficiently a given
contention subchannel capacity is utilized.
In high contention mode, the Cisco uBR7100 series MAC scheduler uses collision statistics and sustains
a high frequency of initial ranging slots until it detects a steady ranging state. The CMTS dynamically
varies the frequency of initial ranging slots using the data grant utilization on the upstream channels. The
CMTS trades upstream bandwidth between data grants and initial ranging slots. The CMTS autodetects
a high collision state and switches to low insertion interval mode after a steady state is achieved where
few collisions occur.
The CMTS is careful when monitoring the ranging channel health to revert to a steady state. In steady
state mode, data grants—grant utilization—receive preference over initial ranging slots.
Although the binary exponential backoff algorithm operates in a distributed fashion at different CMs,
the CMTS provides centralized control for the backoff algorithm. To achieve this, it remotely monitors
traffic load—the backlog developing on the contention channel—and then varies the backoff start and
end specified in the MAPs for that upstream channel. This ensures colliding CMs are properly
randomized in time.
The following cable interface commands are available to configure the dynamic contention algorithms:
[no] cable insertion-interval [automatic [Imin [Imax]]] | [msecs]
[no] cable upstream port num range-backoff [automatic] | [start end]
[no] cable upstream port num data-backoff [automatic] | [start end]
Tip
System defaults are to have dynamic ranging interval enabled, dynamic ranging backoff enabled, and
fixed data backoffs for each upstream of a cable interface.
The default automatic insertion interval setting enables the Cisco automatic initial ranging period
algorithm where lower and upper default values of 50 msecs and 2 secs are used. The default automatic
range-backoff enables the dynamic backoff algorithm.
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To deviate from system defaults when modifying the dynamic contention algorithm, use one of the
following commands in cable interface configuration mode.
Command
Purpose
CMTS01(config-if)# [no] cable
Disable or enable the dynamic ranging
interval algorithm. If lower and upper bounds
for varying the period are not specified, the
system uses default values of 50 msecs and 2
secs respectively.
insertion-interval automatic
CMTS01(config-if)# cable insertion-interval
automatic min 25-2000
CMTS01(config-if)# cable insertion-interval
max 500-2000
Set the lower bound on the initial ranging
period for the auto ranging algorithm.
Set the upper bound on initial ranging period
for the auto ranging algorithm.
CMTS01(config-if)# no cable insertion-interval
Reset fixed initial ranging period to default
value of 500 msecs. Also invokes fixed initial
ranging algorithm.
CMTS01(config-if)# cable insertion-interval
Enable fixed initial ranging period algorithm
with specified fixed period (msecs).
100-2000
Configuring the Dynamic Map Advance Algorithm
A CMTS administrator can enhance the upstream throughput from a cable modem connected to the
Cisco uBR7100 series CMTS. The system employs a new algorithm that automatically tunes the
lookahead time in MAPs based on several input parameters for the corresponding upstream channel. The
use of dynamic/optimal lookahead time in MAPs significantly improves the per-modem upstream
throughput.
Caution
Only a trained CMTS administrator should adjust these values.
To configure the dynamic map advance algorithm, use the following command in cable interface
configuration mode.
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Command
Purpose
CMTS01(config-if)# cable
map-advance dynamic [n]|static
Specify a value to enhance the upstream throughput from a
cable modem connected to the Cisco uBR7100 series router.
The n parameter provides the safety factor for the dynamic
map advance algorithm. This parameter is specified in usecs
and controls the amount of extra lookahead time in MAPs to
account for inaccuracies of the measurement system and
software latencies. The default value is 1000 usecs.
You can vary this between 500 to 1500 usecs. This parameter
is a delta value added to the dynamic map-advance that the
algorithm computes. Using larger safety factors increases the
run time lookahead in MAPs, but reduces the upstream
performance.
Use the static keyword for the map advance command. The
Cisco uBR7100 series router will use a fixed lookahead time
in MAPs, regardless of the real propagation delay of the
farthest cable modem on the network. This fixed lookahead
time is computed based on the worst case parameters such as
farthest DOCSIS propagation delay for the CMs.
Caution
Cisco recommends if you are adjusting the dynamic map advance algorithm that you do not reduce the
safety factor below the default value of 1000 usecs in a production network, until you are confident that
the reduced safety factor suffices for your deployment. The default value is chosen to be a safe operating
point for the algorithm.
Configuring Per Modem Filters
You can configure the Cisco uBR7100 series router to filter incoming packets from individual hosts or
cable modems based on the source Media Access Controller (MAC) or Internet Protocol (IP) address.
Definition of filters follows standard Cisco IOS configuration practices for access lists and groups.
To configure per modem filters, use the following commands in cable interface configuration mode.
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Command
Purpose
CMTS01(config-if)# cable {modem |
host | device} {macaddr ipaddr |}
access group acl
Configure access lists to be specified on a per-interface and
per-direction basis. The packets received from cable modems
and individual hosts are filtered based on the cable modem or
the host the packets are received from. Use modem if the
device is a cable modem. Use host if the device is a CPE
device attached to a cable modem.
Define the filter to be applied to the device and a given
address. The macaddr specifies the cable modem’s or CPE
device’s unique MAC address.
Use the ipaddr option to specify the CM or CPE device’s
current IP address.
Use the acl option to assign the CM or CPE device to an
access list. This defines the per-CM or per-host filter
requirements implemented at the CMTS, rather than at the
CM. Access list numbers are 1 to 99 for fast IP access lists,
100 to 199 for show extended IP access lists.
Note
Caution
Access list numbers of 700 to 799 do not apply.
The system applies filters after the cable modem registers with the CMTS. Filter definitions are not saved
across system reboots and must be applied each time a CM registers.
The software supports traps to alert CMTS administrators on CMs going offline or back online. This is
a typical registration and login procedure:
1.
The CM registers with the Cisco uBR7100 series CMTS.
2.
The Cisco uBR7100 series CMTS sends traps to management systems in use for the network.
3.
The management system sets per modem filters using SNMP or rsh.
4.
The user logs in at the server.
5.
The login server obtains required modem and CPE information from the Cisco uBR7100 series
CMTS.
6.
The login server sets per-CPE filter in the Cisco uBR7100 series CMTS. The per-CPE filter
overrides the per modem filter settings.
7.
If the CM goes offline for less than 24 hours, filters that have been defined using the Cisco uBR7100
series CMTS remain active. If a CM stays offline for more than 24 hours, the filter settings are reset.
8.
If the user logs out or the login server detects that the user is not online, the login server sets default
filters for the CM or the CPE device.
Configuring the Maximum Number of Hosts Attached to a Cable Modem
To specify the maximum number of hosts that can be attached to a subscriber’s cable modem, use the
following command in cable interface configuration mode.
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Command
Purpose
CMTS01(config-if)# cable max-hosts n
Specify the maximum number of hosts that can be
attached to a cable modem on this interface. Valid range
is from 0 to 255 hosts. Default = 0.
CMTS01(config-if)# no cable
max-hosts
Reset the allowable number of hosts attached to a cable
modem to the default value of 0 hosts.
Configuring Cable Modem Registration Timeout
By default, registered cable modems that have no upstream activity for three minutes are timed out and
disconnected from the Cisco uBR7100 series CMTS. This timeout interval can be decreased to 2 minutes
or increased up to 60 minutes.
To specify the registration timeout interval for cable modems connected to the Cisco uBR7100 series
CMTS, use the following command in cable interface configuration mode.
Command
Purpose
CMTS01(config-if)# cable
registration-timeout n
Specify the maximum number of minutes allowed to elapse with
no upstream activity before terminating the connection. Valid
range is from 2 to 60 minutes. Default = 3 minutes.
Clearing Cable Modem Reset
To remove a single cable modem (or all cable modems) from the station maintenance list and reset the
cable modem (or all cable modems) on the network, use one of the following commands in cable
interface configuration mode.
Command
Purpose
CMTS01(config-if)# clear cable modem
Remove the CM with a specific MAC address from
the station maintenance list and reset it.
mac-addr reset
CMTS01(config-if)# clear cable modem
ip-addr reset
CMTS01(config-if)# clear cable modem all
reset
Remove the CM with a specific IP address from the
station maintenance list and reset it.
Remove all CMs from the station maintenance list
and reset them.
Verifying Clear Cable Modem Reset
To determine if the clear cable modem reset command has removed a cable modem from the station
maintenance list and forced it to start a reset sequence, enter the show cable modem command.
Tip
Be sure you entered the correct cable modem IP address or MAC address when you typed the clear cable
modem reset command. It might take up to 30 seconds for the cable modem to start the reset sequence.
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Note
The clear cable modem reset command is useful if an SNMP manager is not available, or if the cable
modem is unable to obtain an IP address or respond to SNMP messages.
Clearing Cable Modem Counters
To clear the counters for the cable modem(s) in the station maintenance list, use one of the following
commands in cable interface configuration mode.
Command
Purpose
CMTS01(config-if)# clear cable modem
Clear the counters in the station maintenance list
for the CM with a specific MAC address.
mac-addr counters
Clear the counters in the station maintenance list
for the CM with a specific IP address.
CMTS01(config-if)# clear cable modem
ip-addr counters
Clear the counters in the station maintenance list
for all CMs.
CMTS01(config-if)# clear cable modem all
counters
Verifying Clear Cable Modem Counters
To determine if the counters in the station maintenance list are cleared, enter one of the following
commands. The station maintenance list counter is 0.
Command
Purpose
show cable modem ip-address
Displays the status of a cable modem identified by its IP
address.
show cable modem mac-address
Displays the status of a cable modem identified by its MAC
address.
show cable modem interface-address
Displays the status of all cable modems on a particular
upstream.
Configuring Traffic Shaping
Configuring Downstream Rate Limiting and Shaping
To configure downstream rate limiting or shape downstream traffic, use the following command in cable
interface configuration mode.
Command
Purpose
CMTS01(config-if)# [no] cable downstream
rate-limit token-bucket [shaping]
weighted-discard [expwt n]
Enables or disables rate limiting and traffic shaping
on the downstream of a cable interface.
You can use this command in the following ways:
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•
To enable rate limiting on the given downstream port using the token bucket policing algorithm,
enter the cable downstream rate-limit token-bucket command.
•
To enable rate limiting on the given downstream port using the token bucket policing algorithm with
traffic shaping, enter the cable downstream rate-limit token-bucket shaping command.
•
To enable rate limiting on the given downstream port using the token bucket policing algorithm with
a specific traffic shaping time granularity, enter the
cable downstream rate-limit token-bucket shaping granularity 8 command.
Acceptable values are 1, 2, 4, 8, or 16 msecs.
•
To enable rate limiting on the given downstream port using the token bucket policing algorithm with
a specific maximum traffic shaping buffering delay, enter the cable downstream rate-limit
token-bucket shaping granularity 8 command. Acceptable values are 128, 256, 512, or 1028 msecs.
•
To remove rate limiting on the given downstream port, enter the
cable downstream rate-limit token-bucket command.
•
To enable rate limiting on the given downstream port using a weighted packet discard policing
algorithm, and to assign a weight for the exponential moving average of loss rate value, enter the
cable downstream rate-limit weighted-discard 3 command. Acceptable values are 1, 2, 3, or 4.
Configuring Upstream Rate Limiting and Shaping
You can rate limit and shape traffic on a DOCSIS upstream channel. This delays the scheduling of the
upstream packet, which in turn causes the packet to be buffered on the cable CPE device, instead of being
dropped. This allows the user’s TCP/IP stack to pace the application traffic appropriately and approach
throughput commensurate with the subscriber’s defined QoS levels.
To configure upstream rate limiting and shaping, use the following command in cable interface
configuration mode.
Command
Purpose
CMTS01(config-if)# [no] cable
upstream n1 rate-limit
[token-bucket]
Enables or disables DOCSIS rate limiting or shaping on an
upstream channel. The n1 argument depends on the number
of upstream channels on the specific cable modem card.
The software supports:
Tip
•
Generic calendar queuing routines
•
New token bucket policing function
•
Grant shaping application of the calendar queues
•
Upstream rate shaping option to the token bucket keyword
•
A default state change from 1 second burst policing to token bucket with shaping
Upstream grant shaping is per CM (SID). Shaping can be enabled or disabled for the token bucket
algorithm.
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Note
Before the introduction of this feature, the CMTS would drop bandwidth requests from a CM it detected
as exceeding its configured peak upstream rate. Such request dropping affects the throughput
performance of IP-based protocols such as FTP, TCP, and SMTP. With this feature, the CMTS can shape
(buffer) the grants for a CM that is exceeding its upstream rate, rather than dropping the bandwidth
requests.
CMTS01# show interface c1/0 sid 1 counters
Sid
Inpackets Inoctets
Outpackets Outoctets
1
67859
99158800
67570
98734862
Ratelimit
BWReqDrop
2579
Ratelimit
DSPktDrop
0
Configuring Spectrum Management
Combining Blind Strategies and Time Scheduled Spectrum Management
Cisco uBR7100 series software supports combined blind and time scheduled spectrum management:
•
Using blind spectrum management, the number of lost station management messages exceeding a
configured threshold (default = 10) initiates an upstream channel frequency reassignment. The
Cisco uBR7100 series software moves all CMs on the upstream port by sending UCD messages that
contain the next frequency and input power level defined in the spectrum management group. The
frequency change occurs rapidly without data loss and with minimal latency.
•
Using time scheduled spectrum management, the upstream channel frequency reassignment process
is initiated at a configured time of day or week.
With combined blind and time scheduled strategies, blind hop tables are given the capability for
time-variant configuration. The frequency or subband list can change with time. Blind frequency hop is
performed within the spectrum specified to be currently available. An example follows:
uBR(config)#
uBR(config)#
uBR(config)#
uBR(config)#
uBR(config)#
cable
cable
cable
cable
cable
spectrum-group
spectrum-group
spectrum-group
spectrum-group
spectrum-group
2
2
2
4
4
time
time
time
time
time
Mon
Tue
Tue
Fri
Sat
09:00:00
09:05:00
09:00:00
09:00:00
09:00:00
frequency 10000000
delete frequency 10000000
frequency 5000000
band 15000000 25000000
delete band 15000000 25000000
Using Guided Frequency Hop
Using guided frequency hop, the upstream channel frequency is reassigned if a threshold number or
percentage of CMs suddenly go offline. You can adjust the thresholds and assign explicit frequencies or
frequency subbands and associated input power levels in the unified spectrum group table. The
Cisco uBR7100 series CMTS locates the defined channel or a suitable channel and moves all CMs on
the upstream port.
The following example shows that the Cisco uBR7100 series can force the CTMS to change the
upstream to another frequency before the CMTS sends a message to increase output power levels. You
can configure the frequency hop table so that the next entry has the same frequency, but a different power
level:
uBR(config)#
uBR(config)#
uBR(config)#
uBR(config)#
uBR(config)#
cable
cable
cable
cable
cable
spectrum-group
spectrum-group
spectrum-group
spectrum-group
spectrum-group
2
2
2
2
2
frequency
frequency
frequency
frequency
frequency
20000000
20000000 2
20000000 -2
22000000
22000000 2
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Managing Cable Modems on the HFC Network
uBR(config)# cable spectrum-group 2 frequency 22000000 3
The order of the configuration commands defines the order which frequency or power level is changed.
There is always a single allocation set per spectrum group, listing the currently available bands. In the
case of a shared spectrum group, there is also a single free set and “in-use” set because there is a single
RF domain. Otherwise, there are free and in-use sets for each upstream port because each upstream port
has its own RF domain.
Sample output:
noisy1# show cable spec
Group Frequency
Upstream
No.
Band
Port
(Mhz)
1
1
1
1
1
2
2
3
3
3
3
3
3
4
4
5
5
5
5
5
5
10.000- 0.000
11.000- 0.000
12.000- 0.000
13.000- 0.000
14.000- 0.000
10.000-15.000
10.208 [0.40]
20.000- 0.000
21.000- 0.000
22.000- 0.000
23.000- 0.000
24.000- 0.000
0.400 [0.80]
20.000-25.000
20.800 [1.60]
10.000- 0.000
11.000- 0.000
12.000- 0.000
13.000- 0.000
14.000- 0.000
13.000- 0.000
Weekly Scheduled
Availability
From Time:
To Time:
Power
Level
(dBmV)
Shared
Spectrum
No
No
No
No
No
No
Mon 17:06:00
Mon 17:08:00
Mon 17:10:00
1
1
1
1
1
2
2
3
3
3
3
3
3
4
4
5
5
5
5
5
5
Cable1/0 U1
Cable1/0 U2
Cable1/0 U3
--- --:--:---- --:--:---- --:--:--
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
To display information about a specific interface or upstream port, enter the
show cable hop cable-if [upstream portnum] command. Information lines describe the frequency hop
status of an upstream port.
Table 5-1
show cable hop Command Parameters
Field
Description
Upstream Port
The upstream port for this information line
Port Status
Show “down” if frequency is unassigned, “admindown” if the port is
shutdown, or the center frequency of the channel if the port is up
Poll Rate
The rate station maintenance polls are generated (msec)
Missed Poll Count
The number of missing polls
Min Poll Sample
The number of polls in the sample
Missed Poll Pcnt
The ratio of missing polls to the number of polls displayed as a percentage
Hop Thres Pcnt
The level that the missed poll percentage must exceed to trigger a frequency
hop expressed as a percentage
Hop Period
The maximum rate which frequency hopping will occur (seconds)
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Table 5-1
show cable hop Command Parameters (continued)
Field
Description
Corr FEC Errors
The number of correctable FEC errors on this upstream port
Uncorr FEC Errors
The number of uncorrectable FEC errors on this upstream port
Sample output:
noisy1# show cable hop
Upstream
Port
Poll Missed
Port
Status
Rate Poll
(ms) Count
Cable1/0/U0 down
1000 * * *
Cable1/0/U1 admindown 1000 * * *
Cable1/0/U2 admindown 1000 * * *
Cable1/0/U3 admindown 1000 * * *
Cable1/0/U0 10.800 Mhz 1000 0
Cable1/0/U0 down
1000 * * *
Min
Missed Hop
Hop
Corr
Poll
Poll
Thres Period FEC
Sample Pcnt
Pcnt (sec)
Errors
frequency not set
* * * 0
interface is down
* * * 0
interface is down
* * * 0
interface is down
* * * 0
0
----- 100% 300
0
frequency not set
* * * 0
Uncorr
FEC
Errors
0
0
0
0
0
0
Spectrum Management Debug and Test Commands
To enable display of frequency hopping debugging messages, enter:
debug cable freqhop
To enable display of spectrum management debugging messages, enter:
debug cable specmgmt
This command also enables display of channel width list and offer list for the
show cable spectrum-group command.
To force a frequency hop decision on the port or ports, enter:
test cable hop cable-if [upstream portnum]
show cable hop Command
You can use the following command to obtain specific upstream interface information:
show cable hop cable-if [upstream portnum]
Table 5-2
show cable hop Command Parameter Descriptions
Field
Description
Upstream Port
Upstream port for this information line
Port Status
Shows “down” if frequency is unassigned, “admindown” if the port is
shutdown, or the center frequency of the channel if the port is up
Poll Rate
Rate that station maintenance polls are generated (msec)
Missed Poll Count
Number of missing polls
Min Poll Sample
Number of polls in the sample
Missed Poll Pcnt
Ratio of missing polls to the number of polls expressed as a percentage
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Table 5-2
show cable hop Command Parameter Descriptions
Field
Description
Hop Thres Pcnt
Level that the missed poll percentage must exceed to trigger a frequency hop
expressed as a percentage
Hop Period
Maximum rate which frequency hopping will occur (seconds)
Corr FEC Errors
Number of correctable FEC errors on this upstream port
Uncorr FEC Errors
Number of uncorrectable FEC errors on this upstream port
noisy1# show cable hop
Upstream
Port
Poll Missed
Port
Status
Rate Poll
(ms) Count
Cable1/0/U0 down
1000 * * *
Cable1/0/U1 admindown 1000 * * *
Cable1/0/U2 admindown 1000 * * *
Cable1/0/U3 admindown 1000 * * *
Cable1/0/U0 10.800 Mhz 1000 0
Cable1/0/U0 down
1000 * * *
Min
Missed Hop
Hop
Corr
Poll
Poll
Thres Period FEC
Sample Pcnt
Pcnt (sec)
Errors
frequency not set
* * * 0
interface is down
* * * 0
interface is down
* * * 0
interface is down
* * * 0
0
----- 100% 300
0
frequency not set
* * * 0
Uncorr
FEC
Errors
0
0
0
0
0
0
You can use the following command to obtain specific upstream interface information:
show cable hop cable-if [upstream portnum]
Table 5-3
Upstream Port Field Parameter Descriptions
Field
Description
Upstream Port
Upstream port for this information line
Port Status
Shows “down” if frequency is unassigned, “admindown” if the port is
shutdown, or the center frequency of the channel if the port is up
Poll Rate
Rate that station maintenance polls are generated (msec)
Missed Poll Count
Number of missing polls
Min Poll Sample
Number of polls in the sample
Missed Poll Pcnt
Ratio of missing polls to the number of polls expressed as a percentage
Hop Thres Pcnt
Level that the missed poll percentage must exceed to trigger a frequency hop
expressed as a percentage
Hop Period
Maximum rate at which frequency hopping will occur (seconds)
Corr FEC Errors
Number of correctable FEC errors on this upstream port
Uncorr FEC Errors
Number of uncorrectable FEC errors on this upstream port
Sample output:
noisy1# show cable hop
Upstream
Port
Poll Missed
Port
Status
Rate Poll
(ms) Count
Cable1/0/U0 down
1000 * * *
Cable1/0/U1 admindown 1000 * * *
Cable1/0/U2 admindown 1000 * * *
Cable1/0/U3 admindown 1000 * * *
Cable1/0/U0 10.800 Mhz 1000 0
Cable1/0/U0 down
1000 * * *
Min
Missed Hop
Hop
Corr
Poll
Poll
Thres Period FEC
Sample Pcnt
Pcnt (sec)
Errors
frequency not set
* * * 0
interface is down
* * * 0
interface is down
* * * 0
interface is down
* * * 0
0
----- 100% 300
0
frequency not set
* * * 0
Uncorr
FEC
Errors
0
0
0
0
0
0
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Polling Cable Modems
Debug and Test Commands
To enable display of frequency hopping debugging messages, enter:
debug cable freqhop
To enable display of spectrum management debugging messages, enter:
debug cable specmgmt
To force a frequency hop decision on the port or ports, enter:
test cable hop cable-if I portnum
Polling Cable Modems
You can obtain operating statistics and determine the state of CMs on the network. The Cisco uBR7100
series CMTS supports polling of CMs to obtain parameter and status information on an ongoing basis.
The following Cisco IOS commands have been added to support the feature:
•
cable modem remote configures the router for the polling interval; the no version of this command
disables the status polling.
•
show cable modem remote-query displays the collected information: downstream receive power
level, downstream signal to noise ratio, upstream power level, micro reflection in dB.
The Cisco uBR7100 series CMTS polls CMs on the network and caches the state information on the
CMTS, allowing administrators to use SNMP to manage the system.
This section describes how you can enable this. See the following configuration tasks:
•
“Enabling SNMP” section on page 5-15 (required)
•
“Configuring Remote Modem Monitoring” section on page 5-15 (required)
Enabling SNMP
Command
Purpose
Router(config)# snmp-server manager
Opens the SNMP manager.
Router(config)# snmp-server community [Community
String] [Permissions]
Defines user permissions.
Configuring Remote Modem Monitoring
Command
Purpose
Router(config)# cable modem remote-query
[polling interval] [Community string]
Specifies how often SNMP polls the modem
and allows you to configure access.
Verifying Remote Query Information
To display information from a queried modem, enter the show cable modem remote-query command.
R7732-01-uBR7246# show cable modem remote-query
IP address
MAC address
S/N
US
DS
Ratio Power Power
5.108.1.2
0010.4bd7.ccf2
0.0
0.0
0.0
5.109.1.2
0000.0000.0022
0.0
0.0
0.0
Tx Time
Offset
0
0
Micro (dB) Modem
Reflection State
0 offline
0 offline
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5.110.1.2
5.108.1.5
5.108.1.4
5.108.1.3
Tip
0000.0000.0023
0000.0000.0026
0000.0000.0024
0000.0000.0025
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0
0
0
0
0
0
0
0
offline
offline
offline
offline
To display debugging information, enter the debug cable remote-query command.
See the following for an example debug message of a successful poll of a CM:
Router# debug cable remote-query
remote-query debugging is on
.
For IP address 209.165.200.223
Nov 10 15:56:50.241: docsIfSignalQualityEntry.5.4 = 380
Nov 10 15:56:50.241: docsIfMibObjects.2.2.1.3.2 = 360
Nov 10 15:56:50.245: docsIfDownstreamChannelEntry.6.4 = -30
Nov 10 15:56:50.245: docsIfUpstreamChannelEntry.6.3 = 12422
Nov 10 15:56:50.249: docsIfSignalQualityEntry.6.4 = 0
Nov 10 15:56:50.477:
See the following for an example debug message when the waiting queue at the CMTS is empty:
SNMP proxy exec got event, but queue is empty
See the following for an example debug message when you try to modify the polling interval or
community string while polling in is progress:
Community string if modified will not be reflected
Note
The polling interval is changed. To change the community string, you must reconfigure the snmp-server
community command with the new community string.
Monitoring and Maintaining Remote Querying
Use the following show commands to gather status information about the specified modems.
Command
Purpose
Router# show cable flap-list
Displays statistics on the quality of the modem connection.
Router# show cable modem
Displays statistics on modem states.
Router# show cable modem
remote-query
Displays statistics gathered by SNMP agents on modem states.
Router# show interface cable
Displays statistics on the quality of the cable interface.
Router# show interface cable sid
Displays statistics on the service IDs of the specified modems.
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Understanding Show Command Responses
General show Commands
Key show commands include:
•
show cable modem
•
show interface cable
•
show cable qos profile
•
show cable modulation profile
•
show cable spectrum-group
Additional or changed show commands include the following:
•
The show cable qos command shows cable qos-profile n command, where the optional argument n
can be used to display a specific profile.
•
The show int cx/y sid command displays more complete Service ID (SID) status information.
•
The show cable modem command displays a list of options for a single modem to be specified by
entering either the RF CPE device IP address or MAC address:
– SNR information for each CM on each interface
– summary display of the total number of modems connected for each upstream channel
– total number of registered and unregistered modems for the specified interface or upstream
– total number of offline modems for the specified interface or upstream and status for each
offline modem before it went offline
•
The show cable burst-profile command has been removed. Its functions have been incorporated
into the show cable modulation-profile command, which now includes an added option number
that displays the modulation profile number.
•
The show cable flap-list and show cable modem commands indicate when the Cisco uBR7100
series CMTS has detected an unstable return path for a particular modem and has compensated with
a power adjustment. An asterisk (*) appears in the power adjustment field for a modem when a
power adjustment has been made; an exclamation point appears when the modem has reached its
maximum power transmit level and cannot increase its power level any further.
•
The show controller upstream command is enhanced to display the following information on cable
interfaces:
– Upstream channel utilization in minislots
– Contention slots
– Initial ranging slots
– Minislots lost due to the MAP interrupt being too late
You can also limit your search for modem status to specific cable interfaces.
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show cable modem Command
The show cable modem command includes all DOCSIS states, and other useful troubleshooting
information such as last received upstream RF power level and maximum number of provisioned
customer premises equipment.
Note
DOCSIS CMs are required to pass through successive states during registration and provisioning. Using
this information, you can isolate why a CM is offline or unavailable.
Specific added information includes the downstream receive power ratio, downstream SNR, upstream
and downstream power levels, transmit timing offset, and micro reflections in decibels.
For each upstream channel, you can obtain the following information:
•
Total number of modem(s)
•
Number of active modem(s)
•
Number of registered modem(s)
•
Number of unregistered modem(s)
•
Number of offline modem(s)
•
Time the modem(s) went offline
•
Status before the modem(s) went offline
•
Receive power before the modem(s) went offline
Sample show cable modem command output follows:
Router# show cable modem
Interface
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Prim
Sid
1
2
3
4
5
6
7
8
9
10
11
Online
State
online
online
online
online
online
online
online
online
online
online
online
Timing Rec
Offset Power
2257
0.00
2262 *-0.50
2260
0.25
2256
*0.75
2265
*0.50
2256
0.00
4138 !-1.00
4142 !-3.25
4141 !-3.00
4142 !-2.75
4142 !-3.25
QoS CPE IP address
MAC address
3
3
3
3
3
3
3
3
3
3
3
0090.8330.0217
0090.8330.020f
0090.8330.0211
0090.8330.0216
0090.8330.0214
0090.8330.0215
0050.7366.124d
0050.7366.1245
0050.7366.17e3
0050.7366.17ab
0050.7366.17ef
0
0
0
0
0
0
1
1
1
0
1
10.30.128.142
10.30.128.145
10.30.128.146
10.30.128.143
10.30.128.140
10.30.128.141
10.30.128.182
10.30.128.164
10.30.128.185
10.30.128.181
10.30.128.169
The output from the show cable modem command indicates when the Cisco uBR7100 series CMTS has
detected an unstable return path for a particular CM and has compensated with a power adjustment. An
asterisk (*) in the power adjustment field for a CM indicates that a power adjustment has been made. An
exclamation point (!) indicates that the CM has reached its maximum power transmit level and cannot
increase its power level any further.
Columns are described below:
•
prim Sid column reveals the primary (lifeline) service identifier assigned to the CM.
•
SID column is the service identifier.
•
Online State column reveals the state of the modem; values include:
– offline—CM considered offline.
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– offline time—the time the CM went offline; the format is the same as other show cable modem
commands (month, day, time, and year).
– init (r1)—CM sent initial ranging.
– init (r2)—CM is ranging.
– init (rc)—CM ranging complete.
– init (d)—Dhcp request received.
– init (i)—Dhcp reply received; IP address assigned.
– init (o)—Option file transfer started.
– init (t)—TOD exchange started.
– online—CM registered, enabled for data.
– online(d)—CM registered, but network access for the cable modem is disabled.
– online(pk)—CM registered, BPI enabled and KEK assigned.
– online(pt)—CM registered, BPI enabled and TEK assigned.
– reject (m)—CM did attempt to register; registration was refused due to bad MIC.
– reject (c)—CM did attempt to register; registration was refused due to bad COS.
– reject (pk)—KEK modem key assignment rejected.
– reject (pt)—TEK modem key assignment rejected.
•
Rec Power column contains the nominal receive power in decibels for this SID.
Note
An asterisk (*) means that the noise power adjustment method is active for this modem. An
exclamation point (!) means that the modem has reached its maximum transmit power.
•
The QoS column contains the service class assigned to the modem.
•
The CPE column identifies the number of devices behind the modem.
•
The Max CPE column identifies the maximum number of devices configured for the modem.
•
The IP address reveals the modem’s IP address.
•
The MAC address reveals the modem’s MAC address.
•
The Concatenation column reveals if concatenation is enabled (yes) or disabled (no).
•
The Rx SNR column reveals the SNR ratio level in dBmV as perceived by the CM.
Note
This parameter is only meaningful for CMs. A CMTS returns a zero.
•
The S/N Ratio column provides values for remote-queried modems.
•
The US Power column reveals the transmit power level for the upstream channel in dBmV.
•
The DS Power column reveals the received power level at the downstream modem in dBmV.
Note
If the power level measurement is not supported, set this parameter to zero. Also, if the
interface is down, this value will be the CMTS-configured value, the most current CM value,
or zero.
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Understanding Show Command Responses
•
The Tx Timing Offset shows the current round trip time at the CM. The value is used to synchronize
upstream transmission to the CMTS and is measured in units of 6.25 microseconds.
•
The Micro (dB) Reflection column is the total microreflections including in-channel response as
perceived on this interface, measured in Dbc below the signal level.
Note
The value is not assumed to return an absolutely accurate value, but gives a rough indication
of microreflections received on this interface.
•
The Offline Time column reveals when a modem went offline.
•
The Previous State column reveals the modem’s status prior to going offline.
•
The Rx Power column reveals the last receive power measurement for a modem that is offline before
it went offline.
•
SM Exhaust Count reveals the number of times the CMTS declared that modem offline. The modem
can be marked offline for various reasons. Refer to the “show cable modem maintenance Command”
section on page 5-21.
See the following sample for detailed output of the show cable modem command:
Router# show cable modem detail
Interface
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U1
Cable1/0/U1
Cable1/0/U0
Cable1/0/U1
Cable1/0/U1
Cable1/0/U0
Cable1/0/U0
Cable1/0/U1
Cable1/0/U1
Cable1/0/U1
Cable1/0/U0
Cable1/0/U1
Cable1/0/U0
Cable1/0/U0
Cable1/0/U1
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U1
Cable1/0/U0
SID
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
MAC address
0090.8330.0215
0090.8330.0213
0090.8330.0214
0090.8330.0217
0090.8330.020f
0050.7366.17e3
0090.8330.0211
0050.7366.17af
0090.8330.0216
0050.7366.1801
0050.7366.124d
0050.7366.1241
0050.7366.17db
0050.7366.1239
0050.7366.17ab
0050.7366.1db1
0050.7318.e97f
0050.7318.e965
0050.7318.e931
0050.7318.e92d
0050.7318.e97b
0050.7366.1d8d
0050.7318.e953
0050.7366.1d9d
0050.7318.e96b
0050.7366.1d95
0050.7318.e93f
0050.7318.e96d
0050.7318.e941
0050.7366.1dcd
0050.7318.e939
0050.7366.1d8f
0050.7302.3da3
0050.7318.e93b
0050.7318.e901
0050.7366.1dbb
0050.7318.e957
Max CPE
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
Concatenation Rx SNR
yes
yes
yes
yes
yes
no
yes
no
yes
no
no
no
no
no
no
no
26.50
no
23.87
no
23.85
no
26.72
no
23.31
no
23.85
no
26.88
no
26.54
no
23.72
no
23.79
no
23.82
no
26.26
no
23.51
no
26.69
no
26.94
no
23.98
no
27.13
no
26.58
no
26.49
no
26.68
no
23.45
no
26.35
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Troubleshooting the System
Understanding Show Command Responses
Cable1/0/U0 23
Cable1/0/U0 24
0050.7318.e985 3
0050.7366.1dbd 3
no
no
26.40
26.69
Router# show cable modem cable 1/0 upstream 0
Interface
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Prim
Sid
1
2
3
4
5
6
7
8
9
Online
State
offline
offline
init(d)
init(d)
init(d)
init(o)
offline
offline
init(rc)
Timing Rec
Offset Power
2264
-0.50
4137 !-3.50
4136 !-2.50
4138 !-4.75
4137 !-2.25
2251
-0.25
2264
0.75
2266
-0.50
4662
1.00
QoS CPE IP address
MAC address
2
2
2
2
2
2
2
2
2
0090.8330.0214
0050.7366.17d3
0050.7366.17ab
0050.7366.1803
0050.7366.1801
0090.8330.0213
0090.8330.020f
0090.8330.0211
00d0.bad3.c459
0
0
0
0
0
0
0
0
0
209.165.200.2
209.165.200.9
209.165.200.0
209.165.200.0
209.165.200.0
209.165.200.3
209.165.200.4
209.165.200.5
209.165.200.0
Router# show cable modem cable 1/0 upstream 0 unregistered
Interface
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Prim
Sid
1
2
3
4
5
6
7
8
9
Online
State
offline
offline
init(d)
init(d)
init(d)
offline
offline
offline
init(rc)
Timing Rec
Offset Power
2264
-0.50
4137 !-3.50
4136 !-2.75
4137 !-3.25
4141 !-2.75
2251
-0.25
2254
-1.00
2248
0.00
4665
-0.50
QoS CPE IP address
MAC address
2
2
2
2
2
2
2
2
2
0090.8330.0214
0050.7366.17d3
0050.7366.17ab
0050.7366.1803
0050.7366.1801
0090.8330.0213
0090.8330.020f
0090.8330.0211
00d0.bad3.c459
0
0
0
0
0
0
0
0
0
209.165.200.2
209.165.200.9
209.165.200.0
209.165.200.0
209.165.200.0
209.165.200.3
209.165.200.4
209.165.200.5
209.165.200.0
Router# show cable modem cable 1/0 upstream 0 offline
Interface
MAC address
Prim Previous
Sid State
Offline
Time
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
0050.7366.17d3
0090.8330.0213
0090.8330.020f
0090.8330.0211
2
6
7
8
Jan
Jan
Jan
Jan
init(o)
init(o)
init(o)
init(o)
16
16
16
16
Rx
Power
20:30:26 !-3.50
20:30:55 -0.25
20:31:07 -1.00
20:31:23
0.00
Rx
SNR
-----------------
SM
Exhaust
Count
1
181
181
181
show cable modem maintenance Command
When a cable modem is detected to be offline by the CMTS—no reply after 16 retries of station
maintenance requests—the cable modem is marked offline. Besides marking the cable modem and SID
state offline, the SID is removed immediately from the CMTS ranging list, and an aging timer is started
to cleanup the SID completely if the cable modem does not attempt to come online within the next
24 hours.
Output fields are described below:
•
The SM Exhausted Count value refers to the number of times a cable modem was dropped because
it did not reply to station maintenance requests. A CM is removed from the station maintenance list
after 16 times of periodic ranging opportunity without seeing the RNG_REQ from the modem.
•
The SM Aborted Count value refers to the number of times the CM was dropped because its
operational parameters were unacceptable. This includes such reasons as the power level is outside
the acceptable range, or the timing offset keeps changing. The respective times in the command
output indicate when this happened.
Following is a response to the show cable modem maintenance command:
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Chapter 5
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Understanding Show Command Responses
uBR7100# show cable modem maintenance
Interface
SID
MAC Address
Cable1/0/U1
Cable1/0/U0
Cable1/0/U2
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U2
Cable1/0/U1
Cable1/0/U2
Cable1/0/U1
Cable1/0/U1
Cable1/0/U1
Cable1/0/U1
Cable1/0/U2
Cable1/0/U1
1
2
11
13
16
20
24
27
28
30
31
32
33
35
36
0010.7b6b.5e27
0010.7b6b.5e15
0050.731c.b025
0050.731c.b021
0050.731c.b009
0050.731c.bfed
0050.731c.b023
0050.731c.bfeb
0050.731c.bfdf
0050.7366.1a71
0050.7366.1bab
0050.731c.bfe7
0050.731c.bfd3
0050.731c.b041
0050.7366.1ab9
SM Exhausted
SM Aborted
Count
Time
Count
Time
4
Apr 29 19:33:19
0
8
Apr 29 19:34:55
0
1
Apr 29 16:43:39
0
1
Apr 29 15:58:43
0
1
Apr 29 15:58:28
0
1
Apr 28 14:36:22
0
1
Apr 27 10:30:36
0
1
Apr 28 14:54:53
0
1
Apr 28 14:50:55
0
2
Apr 29 17:49:00
0
3
Apr 29 16:21:47
0
0
2
Jan 1 09:00:00
4
Apr 29 15:09:28
0
1
Apr 29 16:17:41
0
2
Apr 29 16:53:26
0
show interface cable Command
To display cable interface information, use the show interface cable privileged EXEC command:
show interface cable slot/port [downstream | upstream]
See the following sample show interface cable command output for a cable modem located in
slot 1/port 0:
Router# show interface cable 1/0
Cable1/0 is up, line protocol is up
Hardware is BCM3210 FPGA, address is 00e0.1e5f.7a60 (bia 00e0.1e5f.7a60)
Internet address is 1.1.1.3/24
MTU 1500 bytes, BW 27000 Kbit, DLY 1000 usec, rely 255/255, load 1/255
Encapsulation, loopback not set, keepalive not set
ARP type: ARPA, ARP Timeout 04:00:00
Last input 4d07h, output 00:00:00, output hang never
Last clearing of “show interface” counters never
Queuing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/75, 0 drops
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
10908 packets input, 855000 bytes, 0 no buffer
Received 3699 broadcasts, 0 runts, 0 giants, 0 throttles
3 input errors, 3 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
5412 packets output, 646488 bytes, 0 underruns
0 output errors, 0 collisions, 13082 interface resets
0 output buffer failures, 0 output buffers swapped out
Note
The show interface upstream command is enhanced to display details on the MAC scheduler state for
an upstream port. Refer to the “Enhanced show interface upstream output Command” section on
page 5-27.
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Understanding Show Command Responses
Table 5-4
show interface cable Command Field Descriptions
Field
Description
Cable slot/port is
up/...administratively down
Indicates whether the interface hardware is currently active or
taken down by the administrator.
line protocol is
up/...administratively down
Indicates whether the software processes that handle the line
protocol believe the interface is usable or if it has been taken down
by the administrator.
hardware
Hardware type and address.
Internet address
Internet address followed by subnet mask.
MTU
Maximum Transmission Unit (MTU) of the interface.
BW
Bandwidth of the interface in kilobits per second.
DLY
Delay of the interface in microseconds.
rely
Reliability of the interface as a fraction of 255, calculated as an
exponential average over 5 minutes. (For example, 255/255 is
100% reliability).
load
Load on the interface as a fraction of 255, calculated as an
exponential average over 5 minutes. (For example, 255/255 is
complete saturation.)
Encapsulation
Encapsulation method assigned to this interface.
ARP type
Type of Address Resolution Protocol (ARP) and timeout value
assigned.
Last input
Number of hours, minutes, and seconds since the last packet was
successfully received by an interface.
output
Number of hours, minutes, and seconds since the last packet was
successfully transmitted by an interface.
Last clearing of “show
interface” counters
Time when the counters that measure cumulative statistics, such as
number of bytes transmitted and received, were last reset to zero.
Queuing strategy
Displays the type of queuing configured for this interface. In the
example output, the type of queuing configured is First In First Out
(FIFO).
Output queue
Number of packets in the output queue. The format of this number
is A/B where A indicates the number of packets in the queue, and
B indicates the maximum number of packets allowed in the queue.
drops
Indicates the number of packets dropped due to a full queue.
input queue/drops
Number of packets in the input queue. The format of this number
is A/B where A indicates the number of packets in the queue, and
B indicates the maximum number of packets allowed in the queue.
drops
Indicates the number of packets dropped due to a full queue.
Five minute input rate
Five minute output rate
Average number of bits and packets transmitted per second in the
last five minutes.
packets input
Total number of error-free packets received by the system.
bytes input
Total number of bytes, including data and MAC encapsulation, in
the error-free packets received by the system.
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Chapter 5
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Understanding Show Command Responses
Table 5-4
show interface cable Command Field Descriptions (continued)
Field
Description
no buffer
Number of received packets discarded because there was no buffer
space in the main system.
Received broadcast
Total number of broadcast or multicast packets received by the
interface.
runts
Number of packets that are discarded because they are smaller than
the medium’s minimum packet size.
giants
Number of packets that are discarded because they exceed the
medium’s maximum packet size.
input errors
Includes runts, giants, no buffers, CRC, frame, overrun, and
ignored counts.
CRC
Indicates the number of times the cyclic redundancy checksum
generated by the originating LAN station or far-end device does
not match the checksum calculated from the data received.
frame
Number of packets received incorrectly (with a CRC error and a
non-integer number of octets).
overrun
Number of times the receiver hardware was unable to forward
received data to a hardware buffer because the input rate exceeded
the receiver’s ability to handle the data.
ignored
Number of received packets ignored by the interface because the
interface hardware ran low on internal buffers.
packets output
Total number of messages transmitted by the system.
bytes
Total number of bytes, including data and MAC encapsulation,
transmitted by the system.
underruns
Number of times the transmitter ran faster than the receiving device
could handle.
output errors
Sum of all errors that prevented the final transmission of packets
out of the interface being examined.
interface resets
Number of times an interface has been completely reset.
output buffer failures
Number of times the output buffer has failed.
output buffer swapped out
Number of times the output buffer has been swapped out.
See the following sample output for the downstream cable interface from the
show interface cable downstream command:
Router# show interface cable 1/0 downstream
Cable1/0: Downstream is up
111947771 packets output, 1579682655 bytes, 0 discarded
0 output errors
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Understanding Show Command Responses
Table 5-5
show interface cable downstream Command Field Descriptions
Field
Description
Cable
Indicates the location of the downstream interface.
Downstream is up/...administratively
down
Indicates the administrative state of the interface.
packets output
Total number of packets transmitted out of this interface.
bytes
Total number of bytes transmitted out of this interface.
discarded
Total number of packets discarded.
output errors
Sum of all errors that prevented downstream
transmission of packets out of this interface.
See the following sample output for the upstream cable interface for upstream cable interface 0 from the
show interface cable upstream command:
Router# show interface cable 1/0 upstream 0
Cable1/0: Upstream 0 is up
Received 16873 broadcasts, 0 multicasts, 73310 unicasts
0 discards, 89053 errors, 0 unknown protocol
90183 packets input, 1 uncorrectable
89042 noise, 0 microreflections
Total Modems On This Upstream Channel : 8 (4 active)
Default MAC scheduler
Queue[Rng Polls] 0/20, fifo queuing, 0 drops
Queue[Cont Mslots] 0/104, fifo queuing, 0 drops
Queue[CIR Grants] 0/20, fair queuing, 0 drops
Queue[BE Grants] 0/30, fair queuing, 0 drops
Queue[Grant Shpr]
0/30, calendar queuing, 0 drops
Reserved slot table currently has 0 CBR entries
Req IEs 134469315, Req/Data IEs 0
Init Mtn IEs 385879, Stn Mtn IEs 131059
Long Grant IEs 10766, Short Grant IEs 15895
Avg upstream channel utilization : 1%
Avg percent contention slots : 97%
Avg percent initial ranging slots : 0%
Avg percent minislots lost on late MAPs : 0%
Total channel bw reserved 0 bps
CIR admission control not enforced
Current minislot count
: 6676390
Flag: 0
Scheduled minislot count : 6676545
Flag: 0
Table 5-6 describes the fields shown in the show interface cable upstream display.
Table 5-6
show interface cable upstream Command Field Descriptions
Field
Description
Cable
Indicates the location of the upstream interface.
Upstream is
up/...administratively
down
Indicates the administrative state of the upstream interface.
Received broadcasts
Number of broadcast packets received through this upstream
interface.
multicasts
Number of multicast packets received through this upstream interface.
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Table 5-6
show interface cable upstream Command Field Descriptions (continued)
Field
Description
unicasts
Number of unicast packets received through this interface.
discards
Number of packets discarded by this interface.
errors
Sum of all errors that prevented upstream transmission of packets
through this interface.
unknown protocol
Number of packets received that were generated using a protocol
unknown to the Cisco uBR7100 series.
packets input
Number of packets received through this upstream interface that were
free from errors.
corrected
Number of error packets received through this upstream interface that
were corrected.
uncorrectable
Number of error packets received through this upstream interface that
could not be corrected.
noise
Number of upstream packets corrupted by line noise.
microreflections
Number of upstream packets corrupted by microreflections.
Guaranteed-rate service
queue depth
Number of bandwidth requests queued up in the Guarantee-rate
queue. This queue is only available to modems that have a reserved
minimum upstream rate in their class of service.
Best-effort service queue
depth
Number of bandwidth requests queued up in the Best-effort queue.
This queue is available to all modems that do not have any reserved
rate on the upstream.
Total Modems On This
Upstream Channel
Number of cable modems currently sharing this upstream channel.
This field also shows how many of these modems are active.
Current Total Bandwidth
Reserved
Total amount of bandwidth reserved by all modems sharing this
upstream channel that require bandwidth reservation. The class of
service for these modems specifies some nonzero value for the
guaranteed-upstream rate. When one of these modems is admitted on
the upstream, this field value is incremented by this
guaranteed-upstream rate value.
CIR admission control
(formerly: Current
Admission Control Status)
Indicates the status of admission control on the upstream channel
ENFORCED status allows users to enable admission control on a per
port basis. This controls how limited bandwidth is allocated. NOT
ENFORCED status indicates that there is no admission control. Every
modem that registers with a class of service specifying a minimum
upstream rate is admitted by the CMTS regardless of how much
aggregate bandwidth is actually available.
Users enable admission control by using the admission control CLI.
Default MAC scheduler
Indicates the status of the MAC scheduler as being in default mode as
opposed to Automated Test Procedure (ATP).
Queue[Rng Polls]
The MAC scheduler queue showing the number of ranging polls.
Queue[Cont Mslos]
The MAC scheduler queue showing the number of forced contention
request slots in MAPS.
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Understanding Show Command Responses
Table 5-6
show interface cable upstream Command Field Descriptions (continued)
Field
Description
Queue[CIR Grants]
The MAC scheduler queue showing the number of CIR grants
pending.
Queue[BE Grants]
The MAC scheduler queue showing the number of BE grants pending.
Queue[Grant Shpr]
The MAC scheduler queue showing the number of grants that have
been buffered for traffic shaping.
drops
Number of packets dropped.
Reserved slot table
currently has 0 CBR
entries
Number of CBR sessions active on an upstream channel at any given
time.
Req IEs
The running counter of request IEs sent in MAPS.
Req/Data IEs
The counter of request/data IEs sent in MAPS.
Init Mtn IEs
The counter of Initial Maintenance IEs.
Stn Mtn IEs
Number of station maintenance (ranging poll) IEs.
Long Grant IEs
Number of long grant IEs.
Short Grant IEs
Number of short grant IEs.
Avg upstream channel
utilization
Indicates on average what percent of the upstream channel bandwidth
is being used.
Avg percent contention
slots
Indicates on average what percent of slots are in contention state.
Avg percent initial
ranging slots
Indicates on average what percent of slots are in initial ranging state.
Avg percent minislots
lost on late MAPs
Indicates on average what percent of slots are lost because a MAP
interrupt was too late.
Current minislot count
(formerly: Last Minislot
Stamp
[current_time_base])
Indicates the current minislot count at the CMTS. FLAG indicates the
timebase reference. This field is used only by developers.
Scheduled minislot count
(formerly: Last Minislot
Stamp
[scheduler_time_base])
Indicates the furthest minislot count allocated at the indicated time.
FLAG indicates the timebase reference. This field is used only by
developers.
Enhanced show interface upstream output Command
The show interface cable upstream command displays detailed MAC scheduler state information for
the upstream port. The example below illustrates the new display:
cmts# show interface cable 1/0 upstream 0
Cable1/0:Upstream 0 is up
Received 13 broadcasts, 0 multicasts, 110 unicasts
0 discards, 106 errors, 0 unknown protocol
123 packets input, 0 uncorrectable
106 noise, 0 microreflections
Total Modems On This Upstream Channel :3 (3 active)
Default MAC scheduler
Queue[Rng Polls] 0/20, fifo queuing, 0 drops
Queue[Cont Mslots] 0/104, fifo queuing, 0 drops
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Queue[CIR Grants] 0/20, fair queuing, 0 drops
Queue[BE Grants] 0/30, fair queuing, 0 drops
Queue[Grant Shpr]
0/30, calendar queuing, 0 drops
Reserved slot table currently has 2 CBR entries
Req IEs 280185, Req/Data IEs 0
Init Mtn IEs 800, Stn Mtn IEs 49
Long Grant IEs 26, Short Grant IEs 15
Avg upstream channel utilization :1%
Avg percent contention slots :97%
Avg percent initial ranging slots :1%
Avg percent minislots lost on late MAPs :0%
Total channel bw reserved 192000 bps
CIR admission control not enforced
Current minislot count
:1165412
Flag:1
Scheduled minislot count :1176227
Flag:1
New items in the display include:
•
Detailed slot queue statistics—Queue [CIR Grants] 0/20, fair queuing, 0 drops in the previous
example, meaning that the queue for CIR-service grants has a current depth of 0, and a maximum
depth of 20. Weighted fair queuing shows grants in this queue.
•
CBR slot scheduling table state—The reserved slot table in the previous example has 2 CBR entries.
This shows that at the time the command was issued, the MAC scheduler had admitted 2 CBR slots
in the reserved slot table.
•
Counters for each type of upstream slot scheduled in the MAPs for this upstream channel—The “Init
Mtn IEs 800” means that the MAC scheduler has added 800 initial maintenance information
elements (slots) at the time the show command was issued.
•
MAC scheduling statistics—Display what percentage of the upstream bandwidth is utilized for each
type of slot on an average.
show interface cable sid Command
To display per-SID counters for bandwidth requests, use the show interface cable privileged EXEC
command:
show interface cable interface sid [sid] counters verbose
Data transport over the RF link uses the registered SID address, rather than the Ethernet address. This
allows multiple hosts to access the network by using a single cable modem.
Note
Use the verbose option to provide SID details.
See the following display output for the verbose keyword extension for SID 1:
Router# show interface c1/0 sid 1 counters verbose
Sid
Input packets
Input octets
Output packets
Output octets
BW requests received
Grants issued
Rate exceeded BW request drops
Rate exceeded DS packet drops
:
:
:
:
:
:
:
:
:
1
39
15964
30
8796
40
40
0
0
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Understanding Show Command Responses
See the following display output for the verbose keyword extension for all SIDs on the specified
interface:
Router# show interface c1/0 sid counters verbose
Sid
Input packets
Input octets
Output packets
Output octets
BW requests received
Grants issued
Rate exceeded BW request drops
Rate exceeded DS packet drops
Sid
Input packets
Input octets
Output packets
Output octets
BW requests received
Grants issued
Rate exceeded BW request drops
Rate exceeded DS packet drops
Sid
Input packets
Input octets
Output packets
Output octets
BW requests received
Grants issued
Rate exceeded BW request drops
Rate exceeded DS packet drops
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
1
39
15964
30
8796
40
40
0
0
2
0
0
0
0
0
0
0
0
3
0
0
0
0
0
0
0
0
See the following display for the SIDs connected to the specified interface:
Lab-CMTS# show inter cab 1/0 sid
Sid
23
24
25
26
27
28
29
30
Prim Type Online
Sid
State
stat init(d)
stat init(d)
stat init(rc)
stat init(d)
stat offline
stat offline
stat offline
dyn init(o)
Admin
Status
enable
enable
enable
enable
enable
enable
enable
enable
QoS Create
Time
2
04:00:54
2
04:00:58
2
04:01:05
2
04:01:10
2
04:01:31
2
04:01:59
2
04:02:07
2
04:03:09
IP Address
MAC Address
209.165.200.0
209.165.200.0
209.165.200.0
209.165.200.0
209.165.200.225
209.165.200.226
209.165.200.227
209.165.200.228
0050.7366.17ab
0050.7366.1803
00d0.bad3.c459
0050.7366.1801
0090.8330.0213
0090.8330.0211
0090.8330.0214
0090.833
See the following connection information for all SIDs on the specified interface:
Router# show interface c1/0 sid connectivity
Sid
1
2
3
1st time
online
15:37:24
15:37:24
15:37:24
Times %online
Online time
Online
min
avg
max
1
99.73
00:00
1h45m
1h45m
1
99.73
00:00
1h45m
1h45m
1
99.73
00:00
1h45m
1h45m
Offline time
min
avg
max
00:17
00:17
00:17
00:17
00:17
00:17
00:17
00:17
00:17
See the following connection information for SID 1 on the specified interface:
Router# show interface c1/0 sid 1 connectivity
Sid
1
1st time
online
15:37:24
Times %online
Online time
Online
min
avg
max
1
99.72
00:00
1h41m
1h41m
Offline time
min
avg
max
00:17
00:17
00:17
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Understanding Show Command Responses
See the following display for the counters of the SIDs connected to the specified interface:
Router# show interface c1/0 sid counters
Sid
Inpackets
Inoctets
Outpackets Outoctets
1
2
3
40
0
0
16586
0
0
31
0
0
9160
0
0
Ratelimit
BWReqDrop
0
0
0
Ratelimit
DSPktDrop
0
0
0
See the following display for the counters of SID 1 on the specified interface:
Router# show interface c1/0 sid 1 counters
Sid
Inpackets
Inoctets
Outpackets Outoctets
1
39
15964
30
8796
Ratelimit Ratelimit
BWReqDrop DSPktDrop
0
0
Table 5-7 describes the fields shown in the output for the show interface cable sid displays.
Table 5-7
show interface cable sid Command Field Descriptions
Field
Description
Sid
Service identification number.
Prim Sid
The primary service identifier assigned to the modem.
Type
Indicates this SID was created statically at the time of registration
or dynamically by the exchange of dynamic service messages
between the CM and CMTS.
Online State
“Online” means the modem owning this SID is processing traffic.
“Offline” means the modem owning this SID is not processing
traffic.
Admin Status
“Disable” means that the SID has been turned off. “Enable” is the
normal state.
QoS
Quality of service.
Create time
When the SID was created, number of seconds since the system
booted.
Input octets (Inoctets)
Number of octets received by using this SID.
Input packets (Inpackets)
Number of packets received by using this SID.
Output octets (Outoctets)
Number of octets sent from this SID.
Output packets (Outpackets)
Number of packets sent from this SID.
IP address
IP address of the modem owning this SID.
MAC address
MAC address of the modem owning this SID.
BW requests received
Number of bandwidth requests received by this SID.
Grants issued
Number of bandwidth requests granted by this SID.
Rate exceeded BW request
drops
Number of bandwidth requests not granted by this SID.
Rate exceeded DS packet drops
Number of downstream packets lost by this SID.
Ratelimit BWReqDrop
Number of bandwidth requests not granted by this SID.
Ratelimit DSPktDrop
Number of downstream packets lost by this SID.
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Troubleshooting Cable Flap Lists
Table 5-7
show interface cable sid Command Field Descriptions (continued)
Field
Description
1st time online
Time at which the modem with this SID connected.
Times online
Number of times the modem with this SID has connected.
% online
Percentage of time the modem with this SID has been connected.
Online time
Minimum, average, and maximum number of hours and minutes
the modem with this SID has been connected.
Offline time
Minimum, average, and maximum number of hours and minutes
the modem with this SID has been disconnected.
show cable qos profile Command
Following is a response to the show cable qos profile command. The display shows ToS specifications:
uBR7100# show cable qos profile
Service
class
>
1
2
3
4
5
6
Note
Prio Max
Guarantee Max
Max tx
upstream upstream downstream burst
bandwidth bandwidth bandwidth
0
0
0
0
0
0
64000
0
1000000
0
0
1000
0
1000
0
3
256000
0
512000
0
5
1000000
0
10000000
0
3
256000
0
512000
0
TOS TOS
Create
mask value by
0x0
0x0
0x0
0x0
0x0
0x0
0x0
0x0
0x0
0x0
0x0
0x0
cmts(r)
cmts(r)
cmts
cm
cm
cm
B
priv
enab
no
no
no
no
no
yes
The “r” in the “Create by” column means the first two classes of service the CMTS creates are reserved
for CMs that are not online.
Displays upstream packet discards, errors, error-free packets, correctable and uncorrectable errors, noise
and micro-reflection statistics:
show
interface slot/downstream-port upstream
Troubleshooting Cable Flap Lists
The Cisco uBR7100 series maintains a database of flapping cable modems to assist in locating cable
plant problems. The flapping cable interface detector tracks the upstream and downstream performance
of all cable modems on the network, without impacting throughput and performance, or creating
additional packet overhead on the broadband network. The cable interface flap list keeps track of:
•
the cable interface MAC address
•
up and down transitions
•
registration events
•
missed periodic ranging packets
•
upstream power adjustments
•
the physical interface on the Cisco uBR7100 series CMTS
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Troubleshooting Cable Flap Lists
Note
Although this is a Cisco proprietary CMTS feature, it is compatible with all DOCSIS-compliant cable
modems. Unlike SNMP, the flap list uses zero bandwidth.
The flap list collects the following station maintenance statistics:
•
Detects interface up/down flap; the reinsertion counter counts the number of times a cable interface
comes up and inserts into the network. This helps identify potential problems in the downstream
because improperly provisioned cable modems tend to try to reestablish a link repeatedly.
•
Detects intermittent upstream; the keepalive hits versus misses is the number of times cable modems
do not respond or do not respond to the MAC layer keepalive messages. If there are a number of
misses, this points to a potential problem in the upstream.
•
Lists cable interface MAC addresses sorted by flap rate or most recent flap time.
•
Shows power adjustment statistics during station maintenance polling; this represents the number of
times the CMTS tells a cable interface to adjust the transmit power more than 3 dB. If constant
power adjustments are detected, this usually indicates a problem with an amplifier. By looking at
the cable modems in front and behind various amplifiers, you can find the source of failure.
The cable system administrator typically:
•
Sets up a script to periodically poll the flap list, for example, every 15 minutes
•
Uses the resulting data to perform trend analysis to identify the cable modems that are consistently
in the flap list
•
Queries the billing and administrative database for cable interface MAC address-to-street address
translation and generates a report
These reports can be given to the Customer Service Department or the cable plant’s Operations and
Maintenance Department. Using these reports, maintenance personnel can quickly discern how
characteristic patterns of flapping cable modems, street addresses, and flap statistics can indicate which
amplifier or feeder lines are faulty. The reports also help you quickly discern whether problems exist in
your downstream or upstream path, and whether the problem is ingress noise or equipment related.
Default values for the following flap-list configuration commands are:
•
cable flap-list miss-threshold—6 seconds
•
cable flap-list power-adjust—2 dB
•
cable flap-list insertion-time—180 seconds
Note
Since the cable flap list was originally developed, polling mechanisms have been enhanced to have an
increased rate of 1/sec when polls are missed. Cable modems go offline faster than the frequency hop
period. This can cause the frequency to stay fixed while cable modems go offline. To compensate for
this, as appropriate, you can reduce the hop period to 10 seconds.
Tip
The system supports automatic power adjustments. The show cable flap-list and show cable modem
commands indicate when the Cisco uBR7100 series CMTS has detected an unstable return path for a
particular modem, and has compensated with a power adjustment. An asterisk (*) appears in the power
adjustment field for a modem when a power adjustment has been made; an exclamation point (!) appears
when the modem has reached its maximum power transmit level and cannot increase its power level any
further.
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The following tips and scenarios allow you to use the flap list in the most effective way:
•
If a subscriber's cable interface shows a lot of flap list activity, it is having communication problems.
•
If a subscriber's cable interface shows little or no flap list activity, it is communicating reliably; the
problem is probably in the subscriber's computer equipment or in the connection to the
cable interface.
•
The top 10% most active cable interfaces in the flap list are most likely to have difficulties
communicating with the headend.
•
Cable modems with more than 50 power adjustments per day have a suspect upstream path.
•
Cable modems with approximately the same number of hits and misses and with a lot of insertions
have a suspect downstream path (for example, low level into the cable interface).
•
All cable interfaces incrementing the insertion at the same time indicates a provisioning server
failure.
•
Cable modems with high CRC errors have bad upstream paths or in-home wiring problems.
•
Correlating cable interfaces on the same physical upstream port with similar flap list statistics can
quickly resolve outside plant problems to a particular node or geography.
•
Monitoring the flap list cannot affect cable interface communications.
•
The flap list should be saved to a database computer and cleared at least once each day.
•
Important upstream performance data can be obtained by tracking flap list trend data.
•
Important installation quality control and performance data is directly available from the flap list.
Following is a sample response to the show cable flap command:
uBR7100# show cable flap
Mac Addr
0010.9500.461f
0010.9500.446e
0010.9500.38ec
0010.9500.4474
0010.9500.4672
0010.9500.38f0
0010.9500.e8cb
0010.9500.38f6
0010.9500.4671
0010.9500.38eb
0010.9500.3ce2
0010.9500.e8d0
0010.9500.4674
0010.9500.4677
0010.9500.4614
0010.9500.3be9
0010.9500.4609
0010.9500.3cb8
0010.9500.460d
0010.9500.3cba
0010.9500.3cb4
0010.9500.4612
CableIF
C1/0 U1
C1/0 U1
C1/0 U2
C1/0 U2
C1/0 U2
C1/0 U2
C1/0 U2
C1/0 U3
C1/0 U3
C1/0 U0
C1/0 U0
C1/0 U2
C1/0 U2
C1/0 U2
C1/0 U2
C1/0 U2
C1/0 U2
C1/0 U2
C1/0 U3
C1/0 U3
C1/0 U3
C1/0 U3
Ins
56
38
63
65
56
50
0
50
43
57
44
0
56
40
40
63
55
49
46
39
38
38
Hit
18857
18686
18932
18913
18990
18964
6537
19016
18755
36133
35315
13213
36037
35781
21810
22862
22723
22607
22477
22343
22238
22306
Miss
887
2935
1040
1053
2327
2083
183
2511
3212
1608
1907
246
2379
2381
2362
969
2127
1378
2967
3058
2936
2928
CRC
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
P-Adj
1
1
8
3
6
5
1
2
1
6
4
1
4
4
502
0
0
0
2
0
0
0
Flap
116 Jun
80 Jun
138 Jun
137 Jun
124 Jun
111 Jun
5 Jun
104 Jun
89 Jun
126 Jun
99 Jun
5 Jun
121 Jun
91 Jun
586 Jun
128 Jun
112 Jun
102 Jun
96 Jun
81 Jun
79 Jun
79 Jun
Time
1 14:09:12
2 19:03:57
2 23:50:53
2 09:30:09
2 10:44:14
2 20:46:56
2 22:35:48
2 07:46:31
1 19:36:20
2 20:04:58
2 16:42:47
3 04:15:30
3 00:34:12
2 12:14:38
2 21:43:02
1 14:09:03
1 14:08:02
1 14:08:58
2 17:03:48
1 14:13:16
1 14:09:26
1 14:09:29
The command line with an arrow next to it reveals a cable interface that is continuously flapping. A high
flap rate indicates that the cable interface is power adjusting frequently. This can indicate a problem with
an amplifier. The number reveals the number of times the CMTS instructed the cable interface to adjust
the transmit power more than 3 dB.
Cable modems are automatically added to the flap list when any of the following conditions are detected:
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•
When the cable modem re-registers more frequently than the user-specified insertion time.
•
When intermittent keepalive messages are detected between the CMTS and the cable modem.
•
When the cable modem’s upstream transmit power is adjusted beyond the user-specified power
threshold.
Displaying the Flap List
The flap list can be queried either using the standard Simple Network Management (SNMP) API or the
CLI. Using any third party SNMP Management Information Base (MIB) browser, you can query the
ccsFlapTable in the CISCO-CABLE-SPECTRUM-MIB, a proprietary extension to the DOCSIS MIBs.
Using the show cable flap list command, the flap list statistics are accessed. Refer to the following
example. Each of the columns in the display are described in Table 5-8:
MAC ID___ CableIF
0010.7b6b.60ad C1/0 U0
0010.7b6b.65a3 C1/0 U0
0010.7b6b.6b9d C1/0 U0
Table 5-8
0
0
0
Ins _Hit__
Miss
14386
1390
14503
1264
14060
1726
CRC
1
1
3
P-Adj
38
33
40
Flap ___Time____
41
Nov 24 21:34:24
37
Nov 24 21:28:09
43
Nov 24 21:18:36
Flap List Statistics Description
Statistic
Description
MAC ID
MAC-layer address of a cable modem. The first six digits indicate the
vendor ID of the cable modem manufacturer, followed by six digits
indicating a unique host address. Each cable modem's MAC address is
unique.
Cable IF
The physical upstream interface on the Cisco uBR7100 series CMTS. It
denotes the cable modem card slot number, the downstream port number on
the RF line card and the upstream port number on the same cable modem
card. The flap list data can be sorted based on the upstream port number
which is useful when isolating reverse path problems unique to certain
combining groups.
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Table 5-8
Flap List Statistics Description (continued)
Statistic
Description
Insertions
Link insertion is the process whereby a modem performs an initial
maintenance procedure to establish link with the CMTS. The Ins column is
the flapping modem’s insertion count and indicates the number of times the
RF link was abnormally re-established. An abnormality is detected when
the time between link re-establishment attempts is less than the
user-configurable parameter.
Normal modem activity uses the following sequence below.
•
Initial link insertion is followed by a keepalive loop between the CMTS
and cable modem and is called station maintenance.
•
Power-on
•
Initial maintenance
•
Station maintenance
•
Power-off
When the link is broken, initial maintenance is repeated to re-establish the
link.
•
Initial maintenance @ Time T1
•
Station maintenance
•
Init maintenance
@ Time T2
The Ins and Flap counters in the flap list are incremented whenever T2 –
T1 < N where N is the insertion-time parameter configured in <cable
flap-list insertion-time>.
A high Ins number indicates:
•
Intermittent downstream sync loss
•
DHCP or modem registration problems
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Table 5-8
Flap List Statistics Description (continued)
Statistic
Description
Hit and Miss
The HIT and MISS columns are keepalive polling statistics between the
Cisco uBR7100 series and the cable modem. The station maintenance
process occurs for every modem approximately every 25 seconds. When the
CMTS receives a response from the modem, the event is counted as a Hit.
If the CMTS does not receive a response from the cable modem, the event
is counted as a Miss. A cable modem will fail to respond either because of
noise or if it is down. Modems which only log Misses and zero Hits are
assumed to be powered off.
Misses are not desirable since this is usually an indication of a return path
problem; however, having a small number of misses is normal. The flap
count is incremented if there are M consecutive misses where M is
configured in the cable flap miss-threshold parameter. The parameter value
ranges from 1 to 12 with a default of 6.
Ideally, the HIT count should be much greater than the Miss counts. If a
modem has a HIT count much less than its MISS count, then registration is
failing. Noisy links cause the MISS/HIT ratio to deviate from a nominal 1%
or less. High Miss counts can indicate:
Cyclical Redundancy
Check (CRC)
•
Intermittent upstream possibly due to noise
•
Laser clipping
•
Common-path distortion
•
Ingress or interference
•
Too much or too little upstream attenuation
This statistic tracks the CRC error counter per modem. CRC errors are
usually an indication of noise on a plant. A low count can be always be
expected but a high CRC number calls for some the plant troubleshooting.
The CRC counter indicates:
•
Intermittent upstream
•
Laser clipping
•
Common-path distortion
•
Impulsive noise or interference
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Table 5-8
Flap List Statistics Description (continued)
Statistic
Description
Power Adjustments
(P-Adj)
The station maintenance poll in the CMTS constantly adjusts the modem
transmit power, frequency, and timing. The P-Adj column indicates the
number of times the modem’s power adjustment exceeded the threshold
value. The power adjustment threshold may be set using the <cable flap
power threshold > parameter with a value range of 0 to 10 dB and a default
value of 2 dB. Tuning this threshold is recommended to decrease irrelevant
entries in the flap list. Power Adjustment values of 2 dB and below will
continuously increment the P-Adj counter. The modem transmitter step size
is 1.5 dB, whereas the headend may command 0.25 dB step sizes. Power
adjustment flap strongly suggests upstream plant problems such as:
Flap
Time
•
Amplifier degradation
•
Poor connections
•
Thermal sensitivity
•
Attenuation problem
The Flap counter indicates the number of times the modem has flapped.
This counter is incremented when one of the following events is detected:
•
Unusual modem insertion or reregistration attempts. The Flap and the
Ins counters are incremented when the modem tries to reestablish the
RF link with the CMTS within a period of time that is less than the
user-configurable insertion interval value.
•
Abnormal Miss/Hit ratio. The Flap counter is incremented when N
consecutive Misses are detected after a Hit where N can be
user-configurable with a default value of 6.
•
Unusual power adjustment. The Flap and P-adj counters are
incremented when the modem’s upstream power is adjusted beyond a
user-configurable power level.
Time is the timestamp indicating the last time the modem flapped. The
value is based on the clock configured on the local Cisco uBR7100 series
CMTS. If no time is configured, this value is based on the current uptime of
the Cisco uBR7100 series CMTS. When a cable modem meets one of the
three flap list criteria, the Flap counter is incremental and Time is set to the
current time.
Troubleshooting with the Flap List
This section includes suggestions on how to interpret different network conditions based on the flap list
statistics:
•
Condition 1: Low miss/hit ratio (< 2% for MC16 card), low insertion, low P-adj, low flap counter
and old timestamp.
Analysis: This exhibits an optimal network situation.
•
Condition 2: High ratio of misses over hits (> 10%).
Analysis: Hit/miss analysis should be done after the "Ins" count stops incrementing. In general, if
the hit and miss counts are about the same order of magnitude, the upstream can be experiencing
noise. If the miss count is greater, then the modem is probably dropping out frequently and not
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Troubleshooting Cable Flap Lists
completing registration. The upstream or downstream might not be stable enough for reliable link
establishment. Very low hits and miss counters and high insertion counters indicate provisioning
problems.
•
Condition 3: Relatively high power adjustment counter.
Analysis: Indicates the power adjustment threshold is probably set at default value of 2 dB
adjustment. The modem transmitter step size is 1.5 dB, but the headend can command 0.25 dB step
sizes. Tuning your power threshold to 6 dB is recommended to decrease irrelevant entries in the flap
list. The power adjustment threshold can be set using cable flap power threshold <0-10 dB> from
the Cisco IOS global configuration mode. A properly operating HFC network with short amplifier
cascades can use a 2 to 3 dB threshold.
•
Condition 4: High P-Adj and CRC errors.
Analysis: This condition can indicate that the fiber node is clipping the upstream return laser.
Evaluate the modems with the highest CRC count first. If the modems are not going offline
(Ins = 0), this will not be noticed by subscribers. However, they could receive slower service due to
dropped IP packets in the upstream. This condition also results in input errors on the Cisco uBR7100
series router cable interface.
•
Condition 5: High insertion rate.
Analysis: If link re-establishment happens too frequently, the modem is usually having a
registration problem. This is indicated by a high Ins counter which tracks the Flap counter.
Setting Cable Flap List Aging
You can specify the number of days to record and retain flapping activity on cable interfaces currently
in the flap list table. This value is known as the age of the flap list. The valid range is from 1 to 60 days.
To set the age of the cable flap list, use the following command in global configuration mode.
Command
Purpose
CMTS01(config)# cable flap-list aging days
Specifies the number of days to record and retain
flapping activity for the cable modems connected
to this Cisco uBR7100 series CMTS.
Verifying Cable Flap List Aging
To verify that cable flap list aging is set, enter the show cable flap list command:
CMTS01# show cable flap list
Mac Addr
CableIF
Ins
0010.7b6b.5d1d C1/0 U0
0
0010.7b6b.5e15 C1/0 U0
1
0010.7b6b.5e27 C1/0 U0
1
0010.7b6b.5d29 C1/0 U0
1
0010.7b6b.5e2b C1/0 U0
1
Hit
688
707
707
709
710
Miss
169
185
198
205
204
CRC
0
0
0
0
0
P-Adj
0
0
0
0
0
Flap
3
5
5
5
7
Nov
Nov
Nov
Nov
Nov
Time
5 12:28:50
5 12:29:52
5 12:29:55
5 12:29:52
5 12:30:16
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Setting Cable Flap List Insertion Time
You can set the cable flap list insertion time. When a cable interface makes an insertion request more
frequently than the amount of insertion time defined by this command, the cable interface is placed in
the flap list for activity recording. The valid range is from 60 to 86400 seconds.
To set the cable flap list insertion time, use the following command in global configuration mode.
Command
Purpose
CMTS01(config)# cable flap-list
insertion-time seconds
Specifies the insertion time in seconds. Any cable modem
that makes an insertion request more frequently than this
period of time is placed in the flap list.
Verifying Cable Flap List Insertion Time
To verify cable flap list insertion time, enter the show cable flap list command:
CMTS01# show cable flap list
Mac Addr
CableIF
Ins
0010.7b6b.5d1d C1/0 U0
0
0010.7b6b.5e15 C1/0 U0
1
0010.7b6b.5e27 C1/0 U0
1
0010.7b6b.5d29 C1/0 U0
1
0010.7b6b.5e2b C1/0 U0
1
Hit
688
707
707
709
710
Miss
169
185
198
205
204
CRC
0
0
0
0
0
P-Adj
0
0
0
0
0
Flap
3
5
5
5
7
Nov
Nov
Nov
Nov
Nov
Time
5 12:28:50
5 12:29:52
5 12:29:55
5 12:29:52
5 12:30:16
Setting Cable Flap List Power Adjustment Threshold
You can specify the power adjustment threshold that will cause a flap list event to be recorded. When
the power adjustment of a cable interface meets or exceeds the threshold, the cable interface is placed in
the flap list. The valid range is from 1 to 10 dBmV.
Note
A power adjustment threshold of less than 2 dBmV might cause excessive flap list event recording. Cisco
recommends setting this threshold value to 3 dBmV or higher.
To set the power adjustment threshold for flap-list events, use the following command in global
configuration mode.
Command
Purpose
CMTS01(config)# cable flap-list
power-adjust threshold dbmv
Specifies the minimum power adjustment that will constitute
a flap-list event.
Verifying Cable Flap List Power Adjustment Threshold
To verify the cable flap list power adjustment threshold, enter the show cable flap list command:
CMTS01# show cable flap list
Mac Addr
CableIF
Ins
0010.7b6b.5d1d C1/0 U0
0
0010.7b6b.5e15 C1/0 U0
1
0010.7b6b.5e27 C1/0 U0
1
0010.7b6b.5d29 C1/0 U0
1
0010.7b6b.5e2b C1/0 U0
1
Hit
688
707
707
709
710
Miss
169
185
198
205
204
CRC
0
0
0
0
0
P-Adj
0
0
0
0
0
Flap
3
5
5
5
7
Nov
Nov
Nov
Nov
Nov
Time
5 12:28:50
5 12:29:52
5 12:29:55
5 12:29:52
5 12:30:16
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Troubleshooting Cable Flap Lists
Setting Cable Flap List Miss Threshold
You can specify the miss threshold for recording a flap-list event. A miss is the number of times a
cable modem does not acknowledge a MAC layer keepalive message from a cable interface card. An 8%
miss rate is normal for the Cisco cable interface cards. When the number of misses exceeds the
threshold, the cable interface is placed in the flap list.
Note
A high miss rate can indicate intermittent upstream problems, fiber laser clipping, or common-path
distortion.
To set the miss threshold for recording a flap-list event, use the following command in global
configuration mode.
Command
Purpose
CMTS01(config)# cable flap-list
miss-threshold misses
Specifies the number of MAC layer keepalive misses that will
result in the cable modems being place in the flap list.
Verifying Cable Flap List Miss Threshold
To verify the cable flap list miss threshold, enter the show cable flap list command:
CMTS01# show cable flap list
Mac Addr
CableIF
Ins
0010.7b6b.5d1d C1/0 U0
0
0010.7b6b.5e15 C1/0 U0
1
0010.7b6b.5e27 C1/0 U0
1
0010.7b6b.5d29 C1/0 U0
1
0010.7b6b.5e2b C1/0 U0
1
Hit
688
707
707
709
710
Miss
169
185
198
205
204
CRC
0
0
0
0
0
P-Adj
0
0
0
0
0
Flap
3
5
5
5
7
Nov
Nov
Nov
Nov
Nov
Time
5 12:28:50
5 12:29:52
5 12:29:55
5 12:29:52
5 12:30:16
Setting Cable Flap List Size
You can specify the maximum number of cable interfaces that can be listed in the cable flap list tables.
The valid range is from 1 to 8192 cable interfaces. The default is 8192 cable interfaces.
To specify the maximum number of cable modems that can be recorded in the flap list, use the following
command in global configuration mode.
Command
Purpose
CMTS01(config)# cable flap-list size number
Specifies the maximum size of the flap list.
Verifying Cable Flap List Size
To verify the cable flap list size, enter the show cable flap list command:
CMTS01# show cable flap list
Mac Addr
CableIF
Ins
0010.7b6b.5d1d C1/0 U0
0
0010.7b6b.5e15 C1/0 U0
1
0010.7b6b.5e27 C1/0 U0
1
0010.7b6b.5d29 C1/0 U0
1
0010.7b6b.5e2b C1/0 U0
1
Hit
688
707
707
709
710
Miss
169
185
198
205
204
CRC
0
0
0
0
0
P-Adj
0
0
0
0
0
Flap
3
5
5
5
7
Nov
Nov
Nov
Nov
Nov
Time
5 12:28:50
5 12:29:52
5 12:29:55
5 12:29:52
5 12:30:16
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Troubleshooting Cable Flap Lists
Clearing Cable Flap List
To remove a single cable modem from the flap list or to remove all cable modems from the flap list, use
one of the following commands in global configuration mode.
Command
Purpose
CMTS01(config)# clear cable flap-list
mac-addr
Clears the entries in the cable flap list for the cable
modem with this MAC address.
CMTS01(config)# clear cable flap-list all
Clears the entries for all cable modems in the flap
list.
Customizing Other Flap List Values and Related Commands
The following displays flap list with different sorting options:
show cable modem flap-list [cable n | sort-flap | sort-time | sort-interface]
The following sets the threshold value for link establishment:
[no] cable flap-list insertion-time sec
Note
A modem is tagged as flapping if the insertion time exceeds this value. Its value can be set from 60 to
86400 seconds with a default of 180 seconds.
The following sets the number of consecutive missed station maintenance (RNG-RSP) messages that
must be missed for a flap event to occur. Value ranges from 1 to 2 with a default of 6 seconds. The hits
and miss counters are not affected:
[no] cable flap-list miss-threshold miss-threshold
The following clears the counters for a cable modem (or all cable modems) in the station maintenance
list:
clear cable modem {mac-addr | ip-addr | all} counters
The following displays the QoS, modem status, In and Out octets, IP and MAC addresses per SID:
show int cable slot/port sid
The following drops the modem’s RF link by removing a modem from the keep-alive polling list. This
forces the modem to reset:
clear cable-modem {mac-addr | ip-addr | all} reset
The following uses a MAC layer ping to determine if the cable modem is online. It uses smaller data
units on the wire than a standard IP ping, resulting in lower overhead. This command works even if the
IP layer in the modem is down or has not completed registration:
ping DOCSIS cable-modem mac-addr | IP address
The following displays the timing offset, receive power, and QoS values by cable interface, SID, and
MAC address:
show cable modem [ip-address | MAC-address]
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Performing Amplitude Averaging
The following displays the current allocation table and frequency assignments:
show cable spectrum-group [spectrum group number]
The following displays maximum, average, and minimum% online time and offline times for a given SID
on a given Cisco uBR7100 series router interface:
show int slot/port sid connectivity
The following command displays input and output rates, input errors, CRC, frames, overruns, underruns,
collisions, interface resets. High input errors in the CMTS retrieved from this query suggests noisy
upstream. In older versions of the chassis, loose midplane and line card screws caused a similar problem:
show interface slot/downstream-port
Performing Amplitude Averaging
The Cisco uBR7100 series CMTS uses an averaging algorithm to determine the optimum power level
for a cable modem with low carrier-to-noise ratio that is making excessive power adjustments—known
as flapping. To avoid dropping flapping cable modems, the Cisco uBR7100 series CMTS averages a
configurable number of RNG-REQ messages before it makes power adjustments. By compensating for
a potentially unstable return path, the Cisco uBR7100 series CMTS maintains connectivity with affected
cable modems. You can interpret these power adjustments, however, as indicating unstable return path
connections.
The show cable flap-list and show cable modem commands are expanded to indicate which paths the
Cisco uBR7100 series CMTS is making power adjustments and which modems have reached maximum
transmit power settings. These conditions indicate unstable paths that should be serviced.
The following example shows the output of the show cable flap-list command:
Router# show cable flap-list
MAC Address
Upstream
Ins
0010.7bb3.fd19 Cable1/0/U1 0
0010.7bb3.fcfc Cable1/0/U1 0
0010.7bb3.fcdd Cable1/0/U1 0
Hit
Miss
2792 281
19
4
19
4
CRC
0
0
0
P-Adj Flap
*45
58
!43
43
*3
3
Time
Jul 27 16:54:50
Jul 27 16:55:01
Jul 27 16:55:01
The asterisk (*) indicates that the CMTS is using the power adjustment method on this modem. An
exclamation point (!) indicates that the modem has reached maximum transmit power.
Output of the show cable modem command appears below:
Router# show cable modem
Interface
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Cable1/0/U0
Prim
Sid
1
2
3
4
5
6
7
8
9
10
11
Online
State
online
online
online
online
online
online
online
online
online
online
online
Timing Rec
Offset Power
2257
0.00
2262 *-0.50
2260
0.25
2256
*0.75
2265
*0.50
2256
0.00
4138 !-1.00
4142 !-3.25
4141 !-3.00
4142 !-2.75
4142 !-3.25
QoS CPE IP address
MAC address
3
3
3
3
3
3
3
3
3
3
3
0090.8330.0217
0090.8330.020f
0090.8330.0211
0090.8330.0216
0090.8330.0214
0090.8330.0215
0050.7366.124d
0050.7366.1245
0050.7366.17e3
0050.7366.17ab
0050.7366.17ef
0
0
0
0
0
0
1
1
1
0
1
10.30.128.142
10.30.128.145
10.30.128.146
10.30.128.143
10.30.128.140
10.30.128.141
10.30.128.182
10.30.128.164
10.30.128.185
10.30.128.181
10.30.128.169
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Performing Amplitude Averaging
Similar to the show cable flap-list display, the * symbol in the show cable modem output indicates that
the CMTS is using the power adjustment method on this CM. The ! symbol indicates that the CM has
reached maximum transmit power.
This section documents the commands pertaining to amplitude averaging:
•
cable upstream power-adjust noise
•
cable upstream frequency-adjust averaging
Enabling or Disabling Power Adjustment
To enable or disable the power adjustment capability, use the following commands:
cable upstream n power-adjust {threshold [threshold #] | continue [tolerable value] | noise [% of
power adjustment]}
no cable upstream power-adjust
Table 5-9
Cable Upstream Power Adjust Syntax Descriptions
Syntax
Description
n
Specifies the upstream port number.
threshold #
Specifies the power adjustment threshold. The threshold range is from 0 to
10 dB. The default is 1 dB.
tolerable value
Determines if the status of the RNG-RSP should be set to CONTINUE or
SUCCESS. The range is from 2 to 15 dB. The default is 2 dB.
% of power adjustment
Specifies the percentage of power adjustment packets required to switch
from the regular power adjustment method to the noise power adjustment
method. Range is from 10 to 100 percent. The default is 30 percent.
Note
The threshold default is 1 dB. The tolerable value default is 2 dB. The power adjustment is 30 percent.
Caution
Default settings are adequate for system operation. Amplitude averaging is an automatic procedure. In
general, Cisco does not recommend you adjust values. Cisco does recommend, however, that you clean
up your cable plant should you encounter flapping cable modems.
Note
In some instances, you might adjust certain values:
If CMs cannot complete ranging because they have reached maximum power levels, you might try to set
the tolerable value CONTINUE field to a larger value than the default of 2 dB. Values larger than 10 dB
on “C” versions of cable modem cards, or 5 dB on FPGA versions, are not recommended.
If the flap list shows CMs with a large number of power adjustments, but the CMs are not detected as
“noisy,” you might try to decrease the percentage for “noisy.” If you think too many CMs are
unnecessarily detected as “noisy,” you might try to increase it.
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Setting Downstream Test Signals
Setting Frequency Threshold to Affect Power Adjustment
To control power adjustment methods by setting the frequency threshold, use the
cable upstream freq-adj averaging interface configuration command. To disable power adjustments,
use the no form of this command.
cable upstream n freq-adj averaging % of frequency adjustment
no cable upstream freq-adj averaging
Table 5-10 Cable Upstream Freq-adj Averaging Syntax Descriptions
Syntax
Description
n
Specifies the upstream port number.
averaging
Specifies that a percentage of frequency adjustment packets is
required to change the adjustment method from the regular power
adjustment method to the noise power adjustment method.
% of frequency adjustment
Specifies the percentage of frequency adjustment packets required to
switch from the regular power adjustment method to the noise power
adjustment method. Valid range is from 10 to 100 percent.
The following example shows how to change the power adjustment method when the frequency
adjustment packet count reaches 50 percent:
Router(config-if)# cable upstream 0 freq-adj averaging 50
Setting Downstream Test Signals
This feature provides configuration commands that allow you to create downstream test signals. Both
Pseudo Random Bit Stream (PRBS) and unmodulated carrier test signals are now supported.
A PRBS test signal is a random data pattern that has been modulated to look like a real data stream. An
unmodulated test signal is a continuous sine wave that looks like a carrier wave on the downstream
transmission.
See the following required tasks to create PRBS and unmodulated carrier test signals:
•
“Configuring Unmodulated Test Signals” section on page 5-45
•
“Configuring PRBS Test Signals” section on page 5-45
•
“Verifying Test Signal Output” section on page 5-45
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Setting Downstream Test Signals
Configuring Unmodulated Test Signals
Table 5-11 Instructions to Configure Unmodulated Test Signals
Command
Purpose
Step 1
Router(config-if)# cable downstream if-output
continuous-wave
Generates an unmodulated continuous wave signal on the
downstream channel. The interface is shut down.
Step 2
Router(config-if)# no cable downstream
if-output
Stops sending test signals.
Note
Remember to re-enable the interface to resume
normal operations.
Configuring PRBS Test Signals
Table 5-12
Command
Purpose
Step 1
Router(config-if)# cable downstream if-output
prbs
Generates a PRBS test signal on the downstream
channel. The interface is shut down.
Step 2
Router(config-if)# no cable downstream
if-output
Stops sending test signals.
Note
Remember to re-enable the interface to resume
normal operations.
Verifying Test Signal Output
To verify the output of a continuous wave test signal or the output of a PRBS test signal, use a spectrum
analyzer on the downstream channel. The downstream carrier is enabled as a default.
The standard mode of operation is modulated signal output and the interface is active. For PRBS and
continuous wave output, the selected interface is shut down.
The functioning of the no cable downstream if-output command has not changed. The interface is shut
down.
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Pinging Unresponsive Cable Modems
Pinging Unresponsive Cable Modems
Pinging a Cable Modem
Ping DOCSIS is a Cisco patent-pending feature that allows a cable system administrator to quickly
diagnose the health of a channel between the Cisco uBR7100 series and the cable interface. The
technology uses 1/64—the bandwidth of IP ping—and works with cable modems that do not have an IP
address. This allows cable operators to ping cable modems that are unable to complete registration, have
internal bugs, or that are unresponsive due to a crash.
The Ping DOCSIS feature includes a real time view and plot of requested power adjustments, and a
measure of optimal headend reception power. This gives the cable operator the ability to solicit a
configurable number of periodic ranging requests from a cable interface.
To ping a specific cable interface to determine if it is online, use the following command in EXEC mode.
Table 5-13 Instructions to Ping a Cable Modem
Command
Purpose
CMTS01# ping docsis addr
Pings the cable modem with a specific MAC address or IP address to see if it is online.
Verifying the Ping
The ping docsis command returns a verification from a cable modem that is pinged:
Queuing 5 MAC-layer station maintenance intervals, timeout is 25 msec:
!!!!!
Success rate is 100 percent (5/5)
Tip
If you are having trouble, make sure you are using a valid MAC or IP address for the cable interface you
want to ping.
Using the Cable Monitor Feature
The Cable Monitor feature configures the cable interface so that it forwards copies of certain packets to a
specified interface (typically one of the fixed Fast Ethernet ports on the Cisco uBR7100 series router). By
attaching a network analyzer on that interface, you can monitor inbound or outbound packets for specific
types of traffic. This can provide invaluable information about the type of traffic being sent or received, and
whether that traffic contains any errors or unusual characteristics.
Note
Do not confuse the Cable Monitor feature that is available on the Cisco uBR7100 series router with the
Cable Monitor feature available on Cisco cable CPE devices, such as the Cisco uBR924 cable access
router. The CMTS feature allows the analysis of traffic over the cable interface, while the cable CPE
version of this command provides a way for customers to obtain current configuration information when
the CPE cable interface goes down.
The cable monitor cable interface command has the following syntax:
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Using the Cable Monitor Feature
Router(config-if)# cable monitor [outbound | incoming] [timestamp] interface interface
{access-list <name | number> | sid <n> | mac-addr <address> | upstream <n>}[packet-type
{mac [type {map-req | map-grant | dsa | dsc | dsd ... }] | data packet-header {ethernet |
docsis}}]
Enter configuration commands, one per line. Then press ctrl+z.
Router# conf t
Router(config)# int c1/0
Router(config-if)# cable monitor ?
incoming Monitor incoming packets
outbound
Monitor outbound packets
timestamp Enable packet timestamping
interface Interface to forward monitored packets
Router(config-if)# cable monitor incoming ?
timestamp Enable packet timestamping
interface Interface to forward monitored packets
Router(config-if)# cable monitor incoming timestamp ?
interface Interface to forward monitored packets
Router(config-if)# cable monitor incoming timestamp interface e1/0 ?
access-list IP access list name
mac-addrMAC address of the device monitored
sid Service ID to be monitored
upstreamUpstream port to monitor
Router(config-if)# cable monitor incoming timestamp interface e1/0 sid 2 packet-type ?
mac Monitor mac packets
dataMonitor data packets
<cr>
Router(config-if)# cable monitor incoming timestamp interface e1/0 sid 2 packet-type mac ?
typeMonitor selected mac packets
<cr>
Router(config-if)# cable monitor incoming timestamp interface e1/0 sid 2 packet-type mac
type ?
map-req Monitor Requests
map-grantMonitor Grants
dsa Monitor dynamic service addition
dsc Monitor dynamic service change
dsd Monitor dynamic service deletion
Router(config-if)# cable monitor incoming timestamp interface e1/0 sid 2 packet-type mac
type map-req
Show CLI :
Router# show interface cable 1/0 monitor
US/ Time Outbound Flow
Flow Type
DS Stmp Interface Type
Identifier
all yes
Et1/0
mac-addr 0050.5462.008c
us
yes
Et1/0
acc-list 300
us
no
Et1/0
sid
2
all no
Et1/0
acc-list rrr
all no
Et1/0
mac-addr 0042.b013.008c
all no
Et1/0
upstream 0
Flow
Extn.
yes
no
yes
no
yes
yes
Packet
Type
data
mac
data
data
MAC
MAC
Extn. Type
no
no
yes
map-grant
no
no
no
-
Encap
Type
Ethernet
Ethernet
docsis
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Using Cable Interface debug Commands
Note
See the Broadband Command Consolidation manual, available on Cisco.com and the documentation
CD-ROM, for more information on this feature and its commands.
Using Cable Interface debug Commands
To troubleshoot cable interfaces, use the following debug commands in enable (privileged EXEC) mode.
Table 5-14 Instructions to Use Debug Command
Command
Purpose
CMTS01#
debug cable ?
View all debug cable commands that are available.
CMTS01#
undebug all
Turn off all debugging information to the console and choose a more
selective debug command.
Note
Caution
Refer to the debug commands that follow.
The following commands can generate large amounts of output as the number of cable modems grows.
On heavily loaded systems with thousands of cable modems, these commands can dramatically affect
router performance.
debug cable arp Command
This command activates debugging of arp requests on the cable interfaces. When this command is
activated, all cable arp request messages are displayed on the Cisco uBR7100 series router console. The
format for the command follows:
CMTS01# debug cable arp
To deactivate debugging of arp requests, use the following command:
CMTS01# no debug cable arp
debug cable envm Command (Environmental Monitor Messages)
This command activates debugging of the Cisco uBR7100 series environmental monitor. When this
command is activated, all environmental monitor messages are displayed on the Cisco uBR7100 series
router console. The format for the command follows:
CMTS01# debug cable envm
To deactivate debugging of the environmental monitor, use the following command:
CMTS01# no debug cable envm
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Using Cable Interface debug Commands
debug cable err Command (MAC Protocol Errors)
This command activates debugging of cable MAC protocol errors. When this command is activated, any
errors that occur in the cable MAC protocol are displayed on the Cisco uBR7100 series router console.
The format for the command follows:
CMTS01# debug cable err
To deactivate debugging of MAC protocol errors, use the following command:
CMTS01# no debug cable err
debug cable privacy Command (Baseline Privacy)
This command activates debugging of baseline privacy. The format for the command follows:
CMTS01# debug cable privacy
To deactivate debugging of baseline privacy, use the following command:
CMTS01# no debug cable privacy
debug cable keyman Command (Baseline Privacy Activity)
This command activates debugging of the TEK and KEK baseline privacy key activity. When this
command is activated, all activity related to KEK and TEK keys displays on the Cisco uBR7100 series
router console. The format for the command follows:
CMTS01# debug cable keyman
To deactivate debugging of the keys, use the following command:
CMTS01# no debug cable keyman
debug cable mac-messages Command
This command activates debugging of messages generated in the cable MAC that frames and encrypts
downstream RF signals. When this command is activated, messages generated by the cable MAC are
displayed on the Cisco uBR7100 series router console. The format for the command follows:
CMTS01# debug cable mac-messages
To deactivate debugging of cable MAC messages, use the following command:
CMTS01# no debug cable mac-messages
debug cable map Command
This command activates debugging of cable maps that identify data on cable interfaces. When this
command is activated, messages related to cable maps are displayed on the Cisco uBR7100 series router
console. The format for the command follows:
CMTS01# debug cable map
To deactivate debugging of cable maps, use the following command:
CMTS01# no debug cable map
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Using Cable Interface debug Commands
debug cable modems Command
This command activates debugging of cable modems. When this command is activated, messages from
cable modems on the HFC network are displayed on the Cisco uBR7100 series router console. The
format for the command follows:
CMTS01# debug cable modems
To deactivate debugging of cable MAC messages, use the following command:
CMTS01# no debug cable modems
debug cable phy Command (Messages)
This command activates debugging of messages generated in the cable PHY—the physical layer where
upstream and downstream activity between the Cisco uBR7100 series router and the HFC network is
controlled. When this command is activated, messages generated in the cable PHY are displayed on the
Cisco uBR7100 series router console. The format for the command follows:
CMTS01# debug cable phy
To deactivate debugging of the cable PHY, use the following command:
CMTS01# no debug cable phy
debug cable qos Command
This command activates debugging of QoS. When this command is activated, messages related to QoS
parameters are displayed on the Cisco uBR7100 series router console. The format for the command
follows:
CMTS01# debug cable qos
To deactivate debugging of QoS, use the following command:
CMTS01# no debug cable qos
debug cable range Command (Ranging Messages)
This command activates debugging of ranging messages from cable interfaces on the HFC network.
When this command is activated, ranging messages generated when cable interfaces request or change
their upstream frequencies are displayed on the Cisco uBR7100 series router console. The format for the
command follows:
CMTS01# debug cable range
To deactivate debugging of cable interface ranging, use the following command:
CMTS01# no debug cable range
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Using Cable Interface debug Commands
debug cable receive Command (Upstream Messages)
This command activates debugging of upstream messages from cable interfaces. When this command is
activated, any messages generated by cable interfaces and sent to the Cisco uBR7100 series router will
be displayed on the Cisco uBR7100 series router console. The format for the command follows:
CMTS01# debug cable receive
To deactivate debugging of upstream messages, use the following command:
CMTS01# no debug cable receive
debug cable reg Command (Modem Registration Requests)
This command activates debugging of registration requests from cable interfaces on the HFC network.
When this command is activated, messages generated by cable interfaces as they make requests to
connect to the network are displayed on the Cisco uBR7100 series router console. The format for the
command follows:
CMTS01# debug cable reg
To deactivate debugging of cable registration, use the following command:
CMTS01# no debug cable reg
debug cable reset Command (Messages)
This command activates debugging of reset messages from cable interfaces on the HFC network. When
this command is activated, reset messages generated by cable interfaces are displayed on the
Cisco uBR7100 series router console. The format for the command follows:
CMTS01# debug cable reset
To deactivate debugging of cable reset messages, use the following command:
CMTS01# no debug cable reset
debug cable specmgmt Command (Spectrum Management)
This command activates debugging of spectrum management (frequency agility) on the HFC network.
When this command is activated, messages generated because of spectrum group activity are displayed
on the Cisco uBR7100 series router console. Spectrum group activity can be additions or changes to
spectrum groups, or frequency and power level changes controlled by spectrum groups. The format for
the command follows:
CMTS01# debug cable specmgmt
To deactivate debugging of cable spectrum management, use the following command:
CMTS01# no debug cable specmgmt
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Using Cable Interface debug Commands
debug cable startalloc Command (Channel Allocations)
This command activates debugging of channel allocations on the HFC network. When this command is
activated, messages generated when channels are allocated to cable interfaces on the HFC network are
displayed on the Cisco uBR7100 series router console. The format for the command follows:
CMTS01# debug cable startalloc
To deactivate debugging of cable channel allocations, use the following command:
CMTS01# no debug cable startalloc
debug cable transmit Command (CMTS Transmissions)
This command activates debugging of transmissions from the Cisco uBR7100 series router across the
HFC network. When this command is activated, messages generated at the headend are displayed on the
Cisco uBR7100 series router console. The format for the command follows:
CMTS01# debug cable transmit
To deactivate debugging of cable transmissions, use the following command:
CMTS01# no debug cable transmit
debug cable ucc Command (Upstream Channel Change Messages)
This command activates debugging of upstream channel change (UCC) messages generated when
cable interfaces request or are assigned a new channel. When this command is activated, messages
related to upstream channel changes are displayed on the Cisco uBR7100 series router console. The
format for the command follows:
CMTS01# debug cable ucc
To deactivate debugging of cable upstream channel changes, use the following command:
CMTS01# no debug cable ucc
debug cable ucd Command (Upstream Channel Description Messages)
This command activates debugging of upstream channel descriptor (UCD) messages. UCD messages
contain information about upstream channel characteristics and are sent to the cable modems on the HFC
network. Cable modems that are configured to use enhanced upstream channels use these UCD messages
to identify and select an enhanced upstream channel to use. When this command is activated, messages
related to upstream channel descriptors are displayed on the Cisco uBR7100 series router console. The
format for the command is as follows:
CMTS01# debug cable ucd
To deactivate debugging of cable upstream channel descriptor, use the following command:
CMTS01# no debug cable ucd
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A P P E N D I X
A
Configuration Register Information for the Cisco
uBR7100 Series Universal Broadband Routers
The following information is found in this appendix:
•
Configuration Bit Meanings, page A-1
•
Displaying the Configuration Register While Running Cisco IOS, page A-5
•
Displaying the Configuration Register While Running ROM Monitor, page A-6
•
Setting the Configuration Register While Running Cisco IOS, page A-6
•
Setting the Configuration Register While Running ROM Monitor, page A-7
Configuration Bit Meanings
Use the processor configuration register information contained in this appendix to do the following:
•
Set and display the configuration register value
•
Force the system into the bootstrap program
•
Select a boot source and default boot filename
•
Enable or disable the Break function
•
Control broadcast addresses
•
Set the console terminal baud rate
•
Load operating software from ROM
•
Enable booting from a Trivial File Transfer Protocol (TFTP) server
Table A-1 lists the meaning of each of the configuration memory bits. Following the table is a more
in-depth description of each setting.
Table A-1
Configuration Register Bit Settings
Bit No.
Hex
Meaning
00–03
0x0000–0x000F
Boot field
06
0x0040
Causes the system software to ignore nonvolatile random-access
memory (NVRAM) contents
07
0x0080
OEM (original equipment manufacturer) bit enabled
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A-1
Appendix A
Configuration Register Information for the Cisco uBR7100 Series Universal Broadband Routers
Configuration Bit Meanings
Table A-1
Configuration Register Bit Settings (continued)
Bit No.
Hex
Meaning
08
0x0100
Break disabled
10
0x0400
IP broadcast with all zeros
11–12
0x800–0x1000
Console line speed
13
0x2000
Boots default ROM software if initial boot fails
14
0x4000
IP broadcasts do not have network numbers
15
0x8000
Enables diagnostic messages and ignores NVRAM contents
Bits 0–3
The lowest four bits of the processor configuration register (bits 3, 2, 1, and 0) form the boot field.
Table A-2 provides information about the bits settings.
Table A-2
Bits 0–3 Settings
Boot Field
Meaning
0
Stays at the system bootstrap prompt (ROM monitor) on a reload or power cycle
1
Boots the boot helper image as a system image
2
Full boot process, which loads the Cisco IOS image into Flash memory
2-F
Specifies a default filename for booting over the network from a TFTP server
The boot field specifies a number in binary. If you set the boot field value to 0, you must have a console
port access to boot the operating system manually. Boot the operating system by entering the b command
at the bootstrap prompt as follows:
> b [tftp] flash filename
Definitions of the various command options follow:
b—Boots the default system software from ROM
b flash—Boots the first file in Flash memory
b filename [host]—Boots over the network using TFTP
b flash filename—Boots the file (filename) from Flash memory
If you set the boot field value to a value of 2 through F, and there is a valid system boot command stored
in the configuration file, the router boots the system software as directed by that value. (See Table A-3.)
If you set the boot field to any other bit pattern, the router uses the resulting number to form a default
boot filename for netbooting.
If there are no boot commands in the configuration file, the router attempts to boot the first file in system
Flash memory. If no file is found in system Flash memory, the router attempts to netboot a default file
with a name derived from the value of the boot field (for example, cisco2-7200). If the netboot attempt
fails, the boot helper image in boot flash memory will boot up.
If boot commands are in the configuration file, the router software processes each boot command in
sequence until the process is successful or the end of the list is reached. If the end of the list is reached
without a file being successfully booted, the router will retry the netboot commands up to six times if
bit 13 of the configuration register is set, otherwise it will load the operating system software available
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Appendix A
Configuration Register Information for the Cisco uBR7100 Series Universal Broadband Routers
Configuration Bit Meanings
in ROMmon. If bit 13 is not set, the router will continue to netboot images indefinitely. The default
setting for bit 13 is 0. If bit 13 is set, the system boots the boot helper image found in boot flash memory
without any retries.
The server creates a default filename as part of the automatic configuration processes. To form the boot
filename, the server starts with Cisco and links the octal equivalent of the boot field number, a dash, and
the image name. Table A-3 lists the default boot filenames or actions.
Note
A boot system configuration command in the router configuration in NVRAM overrides the default
netboot filename.
Table A-3
Default Boot Filenames
Action/File Name
Bit 3
Bit 2
Bit 1
Bit 0
Bootstrap mode
0
0
0
0
ROM software
0
0
0
1
Flash software
0
0
1
0
cisco3-< image-name1>
0
0
1
1
cisco4-<image-name2>
0
1
0
0
cisco5-<image-name3>
0
1
0
1
cisco6-<image-name4>
0
1
1
0
cisco7-<image-name5>
0
1
1
1
cisco10-<image-name6>
1
0
0
0
cisco11-<image-name7>
1
0
0
1
cisco12-<image-name8>
1
0
1
0
cisco13-<image-name9>
1
0
1
1
cisco14-<image-name10>
1
1
0
0
cisco15-<image-name11>
1
1
0
1
cisco16-<image-name12>
1
1
1
0
cisco17-<image-name13>
1
1
1
1
Bit 6
Bit 6 causes the system software to ignore nonvolatile random-access memory (NVRAM) contents.
Bit 7
Bit 7 enables the OEM bit. It disables the bootstrap messages at startup.
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A-3
Appendix A
Configuration Register Information for the Cisco uBR7100 Series Universal Broadband Routers
Configuration Bit Meanings
Bit 8
Bit 8 controls the console Break key. Setting bit 8 (the factory default) causes the processor to ignore
the console Break key. Clearing bit 8 causes the processor to interpret Break as a command to force the
system into the bootstrap monitor, halting normal operation. A Break can be sent in the first sixty
seconds while the system reboots, regardless of the configuration settings.
Bit 10 and Bit 14
Bit 10 controls the host portion of the Internet IP broadcast address. Setting bit 10 causes the processor
to use all zeros; clearing bit 10 (the factory default) causes the processor to use all ones. B it 10 interacts
with bit 14, which controls the network and subnet portions of the IP broadcast address. Table A-4 shows
the combined effect of bit 10 and bit 14.
Table A-4
Note
Bit 10 and Bit 14 Settings
Bit 14
Bit 10
IP Address (<net> <host>)
Off
Off
<ones><ones>
Off
On
<zeros><zeros>
On
On
<net><zeros>
On
Off
<net><ones>
The console line rate on Cisco universal broadband routers is fixed at 9600 and cannot be changed. For
additional information about configuring baud rates, refer to oneor more of these documents on
Cisco.com:
•
“Configuring the CMTS for the First Time” in the Cisco uBR7100 Series Software Configuration
Guide:
http://www.cisco.com/en/US/docs/cable/cmts/ubr7100/configuration/guide/scg71cfg.html
Bit 11 and Bit 12
Bit 11 and Bit 12 in the configuration register determine the baud rate of the console terminal. Table A-5
shows the bit settings for the four available baud rates. (The factory set default baud rate is 9600.)
Table A-5
Bit 11 and Bit 12 Settings
Baud
Bit 12
Bit 11
9600
0
0
4800
0
1
2400
1
1
1200
1
0
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Appendix A
Configuration Register Information for the Cisco uBR7100 Series Universal Broadband Routers
Displaying the Configuration Register While Running Cisco IOS
Note
The console line rate on Cisco universal broadband routers is fixed at 9600 and cannot be changed. For
additional information about configuring baud rates, refer to oneor more of these documents on
Cisco.com:
•
Chapter 2, “Configuring the Cisco CMTS for the First Time,” in the Cisco uBR7100 Series Software
Configuration Guide (this document):
http://www.cisco.com/en/US/docs/cable/cmts/ubr7100/configuration/guide/scg71cfg.html
Bit 13
Bit 13 determines the server response to a bootload failure. If boot commands are in the configuration
file, the router software processes each boot command in sequence until the process is successful or the
end of the list is reached. If the end of the list is reached without a file being successfully booted, the
router will retry the netboot commands up to six times if bit 13 of the configuration register is set,
otherwise it will load the operating system software available in ROMmon. If bit 13 is not set, the router
will continue to netboot images indefinitely. The default setting for bit 13 is 0. If bit 13 is set, the system
boots the boot helper image found in boot flash memory without any retries.
Bit 15
Bit 15 enables diagnostic messages and ignores NVRAM contents.
Displaying the Configuration Register While Running Cisco IOS
The configuration register can be viewed by using the show version or show hardware command.
The following example illustrates output from the show version commandusing a Cisco uBR7100 series
router:
Router# show version
Cisco Internetwork Operating System Software
IOS (tm) EGR Software (UBR7100-P-M), Released Version 12.1(5)EC
Copyright (c) 1986-2001 by cisco Systems, Inc.
Compiled Thu 10-Aug-01 00:56 by
Image text-base: 0x60008968, data-base: 0x60F84000
ROM: System Bootstrap, Version 12.1(5r)EC, RELEASE SOFTWARE (fc1e)
BOOTFLASH: EGR Software (UBR7100-BOOT-M), Released Version 12.1(5)EC
RACK7522_uBR7114 uptime is 21 hours, 45 minutes
System returned to ROM by reload at 05:53:22 PST Wed Aug 17 2001
System image file is "ubr7100-p-mz"
cisco uBR7114 (EGR) processor (revision A) with 57344K/73728K bytes of memory.
Processor board ID 15495273
R527x CPU at 225Mhz, Implementation 40, Rev 10.0, 2048KB L2 Cache
Last reset from power-on
X.25 software, Version 3.0.0.
National clock card with T1 controller
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A-5
Appendix A Configuration Register Information for the Cisco uBR7100 Series Universal Broadband Routers
Displaying the Configuration Register While Running ROM Monitor
2 FastEthernet/IEEE 802.3 interface(s)
1 Cable Modem network interface(s)
125K bytes of non-volatile configuration memory.
46976K bytes of ATA PCMCIA card at slot 0 (Sector size 512 bytes).
8192K bytes of Flash internal SIMM (Sector size 256K).
Configuration register is 0x0
Displaying the Configuration Register While Running ROM
Monitor
If the bootstrap prompt “>”, the o command displays the virtual configuration register currently in effect.
It includes a description of the bits. See the following sample output:
>o
Configuration register + 02x100 at last boot
Bit#
Configuration register option settings:
15
Diagnostic mode disabled
14
IP broadcasts do not have network numbers
13
Boot default ROM software if network boot fails
12-11
Console speed is 9600 baud
10
IP broadcasts with ones
09
Do not use secondary bootstrap
08
Break disabled
07
OEM disabled
06
Ignore configuration disabled
05
Fast boot disabled
04
Fan boot disabled
03-00
Boot to ROM monitor
If the prompt is “rommon1”, the confreg command displays the virtual configuration register currently
in effect. It includes a description of the bits. See the following sample output:
rommon 1 > confreg
Configuration Summary
enabled are:
load rom after netboot fails
console baud: 9600
boot: the ROM Monitor
Do you wish to change the configuration? y/n
[n]
Setting the Configuration Register While Running Cisco IOS
The configuration register can be set in the configuration mode with the config-register 0x<value>
command. See the following sample output:
Router# config t
Enter configuration commands, one per line. End with CNTRL/Z.
Router(config)#config-register 0x2142
Router(config)#end
Router#
%SYS-5-CONFIG_I: Configured from console by console
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Appendix A
Configuration Register Information for the Cisco uBR7100 Series Universal Broadband Routers
Setting the Configuration Register While Running ROM Monitor
Setting the Configuration Register While Running ROM Monitor
If the prompt is “>”, the or0x<value> command sets the configuration register. See the following sample
output:
>o/r 0x2102
>
If the prompt is “rommon1”, the confreg command sets the configuration register. It prompts the user
about each bit. See the following sample output:
rommon 1 > confreg
Confiuration Summary
enabled are:
load rom after netboot fails
console baud: 9600
boot: the ROM Monitor
do you wish to change the configuration y/n
[n]: y
enable “diagnostic mode”? y/n
[n]:
n
enable
“use net in IP bcast address”? y/n [n]:
n
disable “use rom after netboot fails”? y/n [n]: n
enable
“use all zero broadcast”? y/n [n]: n
enable
“break/abort has effect”? y/n [n]: n
enable
“ignore system config info”? y/n
[n]: n
change console baud rate? y/n [n]: n
change the boot characteristics? y/n
[n]:y
enter to boot:
0 = ROM Monitor
1 = the boot helper image
2 - 15 = boot system
[0]: 2
Configuration Summary:
enabled are:
load rom after netboot fails
console baud: 9600
boot: image sepcified by the boot system commands or default to: cisco2-c7200
do you wish to change the configuration? y/n
[n]
n
You must reset or power cycle for new config to take effect
rommon 2 >
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A-7
Appendix A Configuration Register Information for the Cisco uBR7100 Series Universal Broadband Routers
Setting the Configuration Register While Running ROM Monitor
Cisco uBR7100 Series Universal Broadband Router Software Configuration Guide
A-8
OL-2238-04
INDEX
sync message interval, configuring
A
troubleshooting
AutoInstall configuration, basic
2-7
5-2
3-50
upstream admission control
upstream back-off values
3-14
3-21
upstream cable interface, configuring
B
upstream channel width
configuring
upstream frequency adjustment
1-6
upstream input power level
1-6
broadband
upstream minislot size
3-8
cable modem subnet addressing
upstream rate limiting
Baseline Privacy, configuring
spectrum management
5-3
cable modem subnet addressing
DHCP giaddr
3-41
3-40, 3-41
3-37
3-37
3-16
3-20
3-1
C
3-37
cable downstream annex command
downstream interleave depth
downstream modulation
integrated TOD server
3-6
3-6
3-1
3-5
cable downstream channel-id command
cable downstream if-output command
3-4
3-2
cable downstream interleave-depth command
3-1
managing cable modems
cable downstream modulation command
3-46
3-6
3-6
cable downstream rate-limit token-bucket command
3-45
3-8
cable flap list
QoS profile assignment
3-45
QoS profiles, configuring
reset cable modem counters
reset cable modems
3-17
cable dhcp-giaddr command
downstream cable interface, configuring
QoS permission
3-19
3-1
cable modulation profiles, configuring
cable relay agent
3-18
3-13
upstream timing adjustment
3-50
cable modem authentication
cable profiles
upstream scrambler
3-23
3-14
3-15
upstream power adjustment
3-1
Cisco uBR7100 series
cable flap list
3-16
upstream forward error correction
3-23
Border Gateway Protocol
BPG
3-11
upstream differential encoding
Baseline Privacy
3-9
clearing
3-43
description
5-9
5-31
flap list aging, configuring
5-8
5-38
flap list insertion time, configuring
spectrum group characteristics
spectrum management
5-41
3-1
3-32
flap list miss threshold, configuring
flap list size, configuring
5-39
5-40
5-40
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IN-1
Index
power adjustment threshold, configuring
cable flap-list aging command
cable modem registration timeout
5-39
cable modem upstream address verification
5-38
cable flap-list insertion-time command
cable profiles
5-40
cable flap-list power-adjustment threshold command
5-39
3-40, 3-41
cable relay agent
3-37
downstream channel ID
3-7
cable insertion-interval command
3-1
3-4
downstream helper address
5-5
cable interface
3-7
downstream interleave depth
configuring
downstream modulation
3-1
logical interface numbering
slot numbering
max hosts
3-8
3-45
QoS profile assignment
5-4
3-45
managing
3-46
QoS profiles
max hosts
5-5
set upstream channel width
registration timeout
subnet addressing
3-1
upstream address verification
5-3
cable modulation-profile command
Cable Monitor
3-43
set upstream frequency
5-8
3-10
3-13
spectrum group characteristics
3-32
3-28
sync message interval
5-46
5-2
cable privacy kek command
3-26
upstream back-off values
cable privacy tek command
3-27
upstream cable interface
cable qos-permission command
cable qos-profile command
3-11
set upstream input power level
spectrum groups
3-42
3-21
3-9
upstream differential encoding
3-45
cable registration-timeout command
cable relay-agent-option command
upstream frequency adjustment
5-8
upstream minislot size
3-37
cable routers
configuration
upstream rate limiting
upstream scrambler
3-37
activate downstream carrier
activate IP broadcast echo
3-39
activate IP multicast echo
3-39
activate proxy ARP
flap lists
3-36
activate upstream admission control
baseline privacy
3-17
3-16
3-20
3-50
cable shared-secret command
5-3
cable source-verify command
5-3
cable spectrum-group command
3-28
cable spectrum-group hop command
3-23
cable modem authentication
3-14
3-32
cable spectrum-group shared command
5-3
cable modem insertion interval
3-18
3-19
upstream timing adjustment
3-2
3-14
3-15
upstream power adjustment
activate DHCP giaddr
3-16
upstream forward error correction
3-43
5-4
3-5
5-5
QoS permission
5-3
insertion interval
3-6
downstream rate limiting
2-17
cable modems
authentication
3-6
downstream MPEG framing format
2-17
5-3
3-41
downstream cable interface
5-40
cable helper-address command
cable modulation profiles
5-39
cable flap-list miss-threshold command
cable flap-list size command
5-8
cable sync-interval command
3-32
5-2
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IN-2
OL-2238-04
Index
cable upstream admission-control command
cable upstream channel-width command
cable upstream data-backoff command
enable
3-12
3-16
cable upstream frequency-adjust averaging
command 3-18
cable upstream frequency command
3-15
cable upstream power-adjust command
3-19
cable upstream power-level command
saving
3-17
3-16
3-20
ix
2-25
2-15, 2-24
interface
2-13
reviewing modifications
2-25
configuration bit meanings
A-1
configuration modes, basic
2-15
configuration procedures
AutoInstall
Cisco uBR7100 series
upstream scrambler
Cisco CMTS
2-7
Ethernet interface configuration
3-16
setup command facility
changes, reviewing configuration
2-25
configuration register
configure command
12.2 BC release train and images
1-1, 1-2
determining your Cisco IOS software release
1-4
1-4
Cisco IOS software images
1-5
1-13
downstream rate limiting
2-9
interface parameters
interfaces
2-13
2-14 to 2-15
2-13
the router
3-16
using AutoInstall
5-41
clear cable modem reset command
2-7
using configuration mode
clear cable modem counters command
commands
2-15
sample configuration
3-8
upstream scrambler
clear cable flap-list command
A-1
2-8
examples of
Cisco uBR7100 series
5-8
5-9
2-15
2-15
using the setup command facility
2-8
copy command
running-config startup-config
config terminal
2-13
global parameters
procedure
upgrading to a new software release
2-8
configuring
1-4
description
operational overview
2-13
synchronous serial interface configuration
1-1
Cisco IOS
configure
2-25
files
cautions
caution
2-19
configuration
caution
location
2-21
show startup-config
cable upstream rate-limit token-bucket command
symbol
2-8
show running-config
3-13
cable upstream time-adjust command
2-3
show interfaces cable
3-22
cable upstream scrambler command
2-3
show interfaces
3-10
cable upstream minislot-size command
cable upstream range command
enable secret
setup
3-14
2-7, 2-24
2-15
enable password
3-22
cable upstream differential-encoding command
cable upstream fec command
copy running-config startup-config
3-14
2-7
running-config startup-config command
2-24
2-15
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Index
show interface cable
D
EXEC mode
5-22
2-3
DHCP
giaddr
3-37
DHCP server
F
2-1
DOCSIS
FEC
MPEG framing format
specification
3-5
finding information
1-5
flap list
spectrum group characteristics
3-32
See cable flap list
downstream cable interface
configuring
1-8
5-31
Forward Error Correction
1-8
3-1
downstream channel ID
configuring
G
3-4
downstream helper address
configuring
global parameters, configuring
2-8
3-7
downstream interleave depth
configuring
H
3-6
downstream modulation
configuring
Headend
3-6
Hubs
1-6
1-6
downstream MPEG framing format
configuring
3-5
I
downstream rate limiting
configuring
3-8
IGMP
Downstream signals
1-7
IGRP, setting
dynamic ranging
configuration
1-7
2-10
information, getting
3-22
installation
interface parameters
2-13
interface
E
configuration
enable command
2-15
enable password
2-3
enable secret password
parameters
2-13
Interior Gateway Routing Protocol
2-3
See IGRP
Ethernet, interface configuration parameters
EuroDOCSIS
2-13
2-13
1-11
Internet Group Management Protocol
IP, setting routing protocols for
1-7
2-10
examples
configuring global parameters
2-9
Ethernet and serial interface configuration
show interfaces command output
2-21
2-14, 2-15
M
MAC
1-6
EXEC commands
Cisco uBR7100 Series Universal Broadband Router Software Configuration Guide
IN-4
OL-2238-04
Index
MAPs
profile permission
1-7
Media Access Control
profile enforcement
1-6
modifications to configuration, reviewing
2-25
QPSK
3-45
3-45
1-9
Quadrature Amplitude Modulation
Quadrature Phase Shift Keying
N
nonvolatile random-access memory
1-9
1-9
R
See NVRAM
numbering
replacing or recovering a lost password
cable interface slot
reviewing changes to configuration
2-17
logical interface
2-17
RIP
port adapter slot
2-17
Routing Information Protocol
NVRAM
2-4
2-25
2-10
See RIP
saving and viewing contents in
2-24
S
P
saving the configuration file
password
Service Identifier
enable and enable secret
recovering
PIM
setup command
2-3
2-8
script
1-7
ping docsis command
5-46
port adapters
logical interface numbering
banner information (example)
2-8
interface summary (example)
2-9
System Configuration Dialog (example)
2-9
setup command facility configuration, basic
2-8
2-17
2-17
privileged command level
show commands
2-3
procedures
show interfaces
replacing or recovering a lost password
Protocol Independent Multicast
PSTN
1-7
setup command facility
2-4
slot numbering
2-15, 2-24
2-4
show interfaces cable
2-19
show interface cable command
1-7
SID
1-6
Public Switched Telephone Network
2-21
1-6
5-22
1-7
Simple Network Management Protocol
See SNMP
SNMP
Q
configuring
QAM
software
1-9
See Cisco IOS software
QoS
SONET
Cisco uBR7100 series
profile configuration
2-10
3-43
1-6
spectrum groups
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Index
configuring
creating
configuring
3-32
upstream differential encoding
3-28
Spectrum Management
description
activating
3-16
upstream forward error correction
3-1
spectrum groups
activating
characteristics
configuring
3-11
upstream frequency
3-32
configuring
3-28
spectrum management
3-10
upstream frequency adjustment
enhanced spectrum management
spectrum group commands
system maintenance
3-14
configuring
5-11
3-18
upstream input power level
5-14
configuring
5-14
status
3-13
upstream minislot size
cable interfaces
downstream
upstream
configuring
upstream power adjustment
2-20
configuring
2-20
interfaces
3-19
upstream rate limiting
2-21
symbols, defined
3-15
configuring
ix
Synchronous Optical Network
upstream scrambler
1-6
synchronous serial interfaces, configuring
3-17
2-13
activating
3-16
upstream timing adjustment
configuring
T
TFTP server
2-1
timesaver symbol, defined
ToD server
ix
W
Weighted Fair Queuing
2-1
troubleshooting
WFQ
Cisco uBR7100
3-20
1-6
1-6
3-50
U
upstream admission control
activating
3-14
upstream back-off values
configuring
3-21
upstream cable interface
configuring
3-9
upstream channel
1-8
upstream channel width
Cisco uBR7100 Series Universal Broadband Router Software Configuration Guide
IN-6
OL-2238-04