Cisco Systems 8xDMT Network Router User Manual

Octal-Port DMT ATU-C Line Card
This feature module describes the Cisco IOS support for the octal-port DMT ATU-C (8xDMT) line card.
It includes information on new and modified commands.
This document includes the following sections:
•
Feature Overview, page 1
•
Supported Platforms, page 4
•
Supported Standards, MIBs, and RFCs, page 5
•
Prerequisites, page 6
•
Configuration Tasks, page 6
•
Configuration Examples, page 9
•
Command Reference, page 10
•
Glossary, page 27
Feature Overview
The 8xDMT line card provides higher port density for the Cisco 6015, Cisco 6160, and Cisco 6260. This
line card:
•
Supports eight ADSL modem connections per card.
•
Converts ADSL modulation from the line card into digital data streams to and from the NI-2 card.
•
Negotiates the line rate with the customer premises equipment (CPE) when it trains and bases the
rate on line quality and distance.
•
Provides subscriber and port provisioning through DSL profiles.
– Allows single latency—Fast or interleaved path selection.
– Supports trellis encoding.
– Supports bit swapping.
•
Interoperates with certain CPE. For more detailed information, see the “Supported Platforms”
section on page 4.
Note
Check with a Cisco customer representative to verify CPE compatibility with
the 8xDMT.
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Feature Overview
Benefits
G.hs Support (ITU G.994.1)
G.hs support is provided through both the MIB and the CLI. Features from G.hs that are
supported include:
•
Enabling/disabling all or one of the following modes.
– G.dmt
– T1.413 Issue 2
– G.lite
•
Setting auto mode defers the mode selection to the ATU-R.
•
Displaying current mode/capability.
Bit Swapping
Bit swapping is a mechanism that allows DMT transceivers to reallocate bits between carriers and adjust
gain scaling based on the carrier SNR margin.
Fast or Interleaved Path Selection
The fast path feature allows you to configure either the fast or the interleave path via DSL profile
configuration commands provided that the CPE also supports fast path. You can use either the interleave
or fast path with the 8xDMT line card provided that the CPE also supports fast path. The fast path
provides improved latency characteristics for applications that cannot tolerate latency (for
example, voice).
The parameters for either path are configurable using the DSL profile configuration commands. Note that
although you can configure both paths, only one path will actually be enabled (dual latency is not
supported at this time). Thus the maximum bit rates for the unused path must be zero. For example, to
configure and use the fast path, you must specify nonzero maximum bit rates for the fast path. Once you
configure the maximum bit rates for the fast path, the rates for the interleave path must be zero. The IOS
software ensures that only one path is enabled at a given time.
Trellis Encoding
Trellis encoding is a method of providing better performance in a noisy environment. The end result of
using Trellis encoding is that you can transmit at faster line rates with lower error rates, thus providing
a faster overall throughput in a moderately noisy environment. You can enable or disable trellis encoding
for a specific DSL profile.
Enhanced Line Quality Monitoring and Management
The 8xDMT improves the manageability of DMT ports on supported DSLAMs. The following
commands are used to configure this functionality:
•
dmt minrate-blocking
DMT minrate-blocking customizes the DMT port reaction to lines that train below configured
minimum bit rates. Formerly, if a line trained below the configured minimum bit rate threshold, it
would generate a minor alarm, but the DMT port remained active. The dmt minrate-blocking
prevents DMT ports from training when bit rates fall below the configured minimum threshold
specified in the dmt bitrate minimum command.
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Feature Overview
Note
•
The original option, which generates a minor alarm when configured minimum bit rates are
not met, is configured by default in DSL profiles. The default configuration is no dmt
minrate-blocking.
dmt rate-adaptation
The dmt rate-adaptation command monitors the signal-to-noise ratio (SNR) on DSL lines. When
enabled, software monitors the upstream and downstream DMT ports for low SNR margins. When
the actual upstream or downstream margin falls below the dmt rate-adaptation margin for the
duration of the configured rate-adaptation interval, the line drops and attempts to retrain. If the
line is able to retrain, it trains to a lower bit rate with improved SNR margins.
Restrictions
The 8xDMT card is not spectrally compatible with SDSL, G.shdsl, or IDSL. Place these cards in a
separate chassis half when using them in the same chassis as 8xDMT line cards.
Related Features and Technologies
The 8xDMT line card is an upgrade of the 4xDMT (6260) and 4xFlexi (6160, 6260, 6015) line cards.
Related Documents
Hardware Documents
A complete list of all DSL hardware product related documentation is available on the World Wide Web
at http://www.cisco.com/univercd/cc/td/doc/product/dsl_prod/index.htm.
Software Documents
A complete list of all DSL IOS software product related documentation is available on the World Wide
Web at http://www.cisco.com/univercd/cc/td/doc/product/dsl_prod/ios_dsl/index.htm.
In the ATM software product related documentation, look for information pertaining to the
Cisco LightStream 1010, which uses the same software base as the NI-2 DSL systems. This
documentation is available on the World Wide Web at
http://www.cisco.com/univercd/cc/td/doc/product/atm/index.htm.
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Supported Platforms
Supported Platforms
DSLAMs
This feature supports the 8xDMT line card on the Cisco 6015, Cisco 6160, and Cisco 6260 platforms
with NI-2. Table 1details the total available ADSL modem connections for each chassis.
Table 1
Number of Available Modem Connections for Each Chassis
Chassis
Number of Available 8xDMT
Slots
Total ADSL Modem Connections
Cisco 6015
6
48
Cisco 6160
32
256
Cisco 6260
30
240
The 8xDMT is designed for use with the Cisco 6015, Cisco 6160, or Cisco 6260 chassis in one of the
following configurations:
•
Cisco 6015, Cisco 6160, or Cisco 6260 with a POTS splitter chassis—Provisions one modem
directly and is physically connected to one specific subscriber line through the POTS
splitter chassis.
•
Cisco 6015, Cisco 6160, or Cisco 6260 without a POTS splitter chassis—Provisions one modem
directly and is physically connected to one specific subscriber line through the main distribution
frame (MDF) connections.
CPE
•
Cisco 677
•
Cisco 678
•
Cisco Soho 77
•
Cisco 827
•
Cisco IAD 2423
•
Cisco 1700, Cisco 2600, and Cisco 3600 series with ADSL WIC
•
Alcatel Speed Touch Home
•
Alcatel Speed Touch Pro
•
Efficient Networks 5260 and 5262
•
Westell modems based on Alcatel Microelectronics firmware version 1.4.1
•
CPE using ADI chipsets with firmware versions 0X3019BE70 (Version 3.0),
0X2219BE04 (Version 2.2), or 0X2019BE2D (Version 2.0) should operate similar to the Cisco 677
Note
A correct firmware version does not guarantee interoperation with third-party CPE. Some
hardware variations can affect performance and error rates. Test the interoperation of CPE
with the 8xDMT in the targeted deployment model before provisioning service.
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Supported Standards, MIBs, and RFCs
Supported Standards, MIBs, and RFCs
Standards
•
ANSI T1.413-Issue 2, Category 1 only
•
ANSI T1.413-Issue 2, Annex F (Reduced NEXT)
•
Universal Test & Operations PHY for ATM, Level 2; A standard for transport of ATM cells over a
16-bit parallel data bus. See ATM Forum document af-phy-0039.000.
•
ITU G.992.1, Annex A (G.dmt)
•
ITU G.992.2. (G.lite)
•
ITU G.994.1. (G.hs)
Standard MIBS
To obtain lists of supported MIBs by platform and Cisco IOS release and to download MIB modules, go
to the Cisco MIB web site on Cisco Connection Online (CCO) at
http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml.
•
IETF RFC 1695, Definitions of Managed Objects for ATM Management Version 8.0 using SMIv2
•
IETF RFC 2662, Definitions of Managed Objects for the ADSL Line (obsoletes ADSL Forum TR006, SNMP-based ADSL Line MIB)
– Objects not supported for 8xDMT:
From AdslLineConfProfileEntry - adslAtucConfRateChanRatio, adslAtucConfMaxSnrMgn,
adslAtucConfUpshiftSnrMgn, adslAturConfRateChanRatio, adslAturConfMaxSnrMgn,
adslAturConfUpshiftSnrMgn,adslAturConfMinUpshiftTime.
AdslLineAlarmConfProfileEntry
•
ADSL Forum TR-014, DMT Line Code Specific MIB
– Objects not supported for 8xDMT:
From AdslLineDmtConfProfileEntry- adslAtucDmtConfFreqBins, adslAturDmtConfFreqBins,
adslAtucDmtConfInterleavePath, adslAtucDmtConfFastPath, adslAturDmtConfInterleavePath,
adslAturDmtConfFastPath.
Cisco-Derived MIBS
•
CISCO-ADSL-LINE-MIB
– Objects not supported for DMT8:
•
CISCO-ADSL-DMT-LINE-MIB
– Objects not supported for DMT8:
From the cAdslDmtLineConfProfileGroup cAdslAtucDmtConfBitSwapEnabled,
cAdslAtucDmtConfBitSwapFrom, cAdslAtucDmtConfBitSwapTo. You can set these objects
via SNMP, however, the 8xDMT cards will ignore these objects when provisioning ports
for service.
To obtain lists of supported MIBs by platform and Cisco IOS release and to download MIB modules, go
to the Cisco MIB web site on Cisco Connection Online (CCO) at
http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml.
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Prerequisites
Prerequisites
To use the 8xDMT feature, you must have one of the following DSLAMs with the 8xDMT line card, and
IOS 12.1(6) or above installed:
•
Cisco 6015
•
Cisco 6160
•
Cisco 6260
Configuration Tasks
See the following sections for configuration tasks for the 8xDMT feature. Each task in the list indicates
if the task is optional or required.
•
Preprovisioning the 8xDMT Line Card, page 6 (optional)
•
Creating and Associating a DSL Profile with Each Port, page 7 (required)
•
Modifying the DSL Profile, page 7 (optional)
Preprovisioning the 8xDMT Line Card
Starting at the global configuration prompt, use the following commands to preprovision a slot for use
with the 8xDMT line card:
Command
Purpose
Step 1
DSLAM(config)# slot 1 ATUC-1-DMT8
This command associates the 8xDMT line card with
the specified slot.
Step 2
DSLAM(config)# dsl-profile 8xDMT
Creates and names the DSL profile, 8xDMT in
this example.
Step 3
DSLAM(config-dsl-prof)# exit
Return to the global configuration prompt.
Step 4
DSLAM(config)# interface atm1/1
Enter interface configuration mode on the port
where you will associate the 8xDMT DSL profile.
Repeat this process on each port that you wish to
associate with a DSL profile.
Step 5
DSLAM(config-if)# dsl profile 8xDMT
Associates the DSL profile named 8xDMT with
atm interface 1/1.
Step 6
DSLAM(config-if)# exit
Return to the global configuration prompt.
Tips
After you have completed these steps, insert the 8xDMT line card to activate the card with your
preprovisioned configuration.
Verifying the Preprovisioned Slot
Use the show running-configuration command to verify that you preprovisioned the slot correctly.
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Configuration Tasks
Creating and Associating a DSL Profile with Each Port
Before starting this configuration task, install the 8xDMT line card. Refer to the Octal-Port DMT ATU-C
Line Card FRU Installation and Configuration Notes for information on installing the 8xDMT line card.
Starting at the global configuration prompt, use the following procedure to associate a DSL profile with
a port:
Command
Purpose
Step 1
DSLAM(config)# dsl-profile 8xDMT
Select the profile that you want to attach to the
selected port. The profile name 8xDMT is used as
an example.
Step 2
DSLAM(config-dsl-prof)# exit
Return to the global configuration prompt.
Step 3
DSLAM(config)# interface atm1/1
Enter interface configuration mode on the port
where you will associate the 8xDMT DSL profile.
Repeat this process on each port that you wish to
associate with a DSL profile.
Step 4
DSLAM(config-if)# dsl-profile 8xDMT
Associate the DSL profile 8xDMT with
atm interface 1/1.
Step 5
DSLAM(config-if)# exit
Return to the global configuration prompt.
Verifying the DSL Profiles
You can use the show dsl profile profile-name command to verify that a DSL profile is attached to a port.
You can also use the show running-configuration command to verify that the DSL profile is associated
with a port.
Tips
If no DSL profile appears in the show running-configuration command output, the default
DSL profile is enabled. See the “Command Reference” section on page 10 for the default
configuration values.
Modifying the DSL Profile
Starting at the global configuration prompt, use the following procedure to modify the default bit rate,
signal-to-noise ratio, DMT check bytes, and overhead framing parameters in your DSL profile:
Caution
Before migrating from interleave mode to fast path, determine whether the deployed CPEs offer
support for the feature. The Cisco 600 series CPEs currently do not support fast path.
Command
Purpose
Step 1
DSLAM(config)# dsl-profile 8xDMT
Enter DSL profile configuration mode.
Step 2
DSLAM(config-dsl-profile)# dmt bitrate
maximum fast downstream 3200 upstream 640
Set a DMT bit rate of 3200 kbps downstream and 640 kbps
upstream on the fast path. Automatically configures the
interleaved path to 0 kbps.
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Monitoring and Maintaining the 8xDMT Line Card
Command
Purpose
Step 3
DSLAM(config-dsl-profile)# dmt
check-bytes fast downstream 0 upstream 0
Set the upstream and downstream FEC check (redundancy) bytes
to 0.
Step 4
DSLAM(config-dsl-profile)# dmt margin
downstream 12 upstream 6
Set the downstream and upstream signal-to-noise ratio (SNR)
margins for a DSL profile.
Step 5
DSLAM(config-dsl-profile)# dmt
overhead-framing mode1
Set the overhead framing mode, in this example to 1.
Step 6
DSLAM(config-dsl-profile)# exit
Return to the global configuration prompt.
Troubleshooting Tips
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. To
obtain troubleshooting help, go to the Cisco Troubleshooting Assistant web site on Cisco Connection
Online (CCO) at:
http://www.cisco.com/kobayashi/support/tac/tsa/dslstep.html
Also see the “Monitoring and Maintaining the 8xDMT Line Card” section on page 8.
Monitoring and Maintaining the 8xDMT Line Card
Use the following commands to monitor and maintain the 8xDMT line card:
Command
Purpose
DSLAM# show dsl interface atm slot/port
These commands display basic information about the DSL link,
including port status, dsl statistics, line errors, and cards detected.
DSLAM# show dsl status DMT
DSLAM# show facility-alarm status
The show facility-alarm status command displays all of the current
major and minor alarms and the user-configurable alarm thresholds
for temperature. After an alarm condition is indicated (by LEDs or
bells), you can use the show facility-alarm status command to
determine the cause of the alarm.
Note
DSLAM# show hardware
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You must turn on the alarms in the profile for alarms to
be displayed.
The show hardware command shows information on each of the
slots in your chassis. It tells whether line cards, fan trays, and PEMs
are present.
Octal-Port DMT ATU-C Line Card
Configuration Examples
Configuration Examples
The following example shows a profile named 8xDMT2 being created. The profile uses the default
profile values for any parameters not specified.
Current configuration : 7019 bytes
!
version 12.1
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname DSLAM
!
boot system flash:ni2-dsl-mz.121-6.DA.bin
slot 1 ATUC-4FLEXIDMT
slot 2 ATUC-1-DMT8
slot 3 ATUC-4FLEXIDMT
slot 4 ATUC-4FLEXIDMT
slot 5 ATUC-4FLEXIDMT
slot 6 ATUC-4FLEXIDMT
enable password cisco
!
!
!
!
!
!
dsl-profile default
dmt bitrate maximum interleaved downstream 8032 upstream 864
cap bitrate maximum downstream 7168 upstream 1088
!
dsl-profile 8xdmt
!
dsl-profile 8xDMT2
dmt overhead-framing mode1
dmt check-bytes fast downstream 12 upstream 6
dmt margin downstream 12 upstream 6
dmt bitrate maximum fast downstream 3200 upstream 640
dmt bitrate maximum interleaved downstream 0 upstream 0
network-clock-select 1 system
ip subnet-zero
ip host-routing
no ip finger
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Command Reference
Command Reference
This section documents the new and modified commands that are specific to the8xDMT feature. All
other commands used with this feature are documented in the Command Reference for Cisco DSLAMS
with NI-2. For information on other Cisco IOS commands that can be used on the NI-2 DSL systems,
see the Cisco ATM Switch Router Command Reference Guide.
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alarms
alarms
To enable alarms in profile command mode, use the alarms command. To disable alarms, use the no
form of the command.
alarms
Syntax Description
This command has no keywords or arguments.
Defaults
Disabled.
Command Modes
Profile configuration.
Command History
Release
Modification
12.0(5)DA
This command was introduced in a previous release.
12.1(6)DA
Conditions that cause alarms were added.
Usage Guidelines
The command affects minor alarms for DSL subscriber ports only. The alarms this command controls
apply to these event classes:
•
Near End LOS
•
Near End interleaved LOCD
•
Near End fast LOCD
•
Near End LOF
•
No CPE detected
•
Bit rates below configured minimum
•
Subscriber port failure
•
Upstream or downstream bit rate not above minimum bit rate
Enabling or disabling alarms affects the specified profile only. For example, if you disable alarms on the
default profile, other profiles are unaffected.
Use alarms and no alarms to enable and disable minor alarms related to DSL subscriber ports. When
these alarms are disabled, you receive no notification when alarm conditions exist. (Notification methods
include console messages, LEDs, the output of the show facility-alarm command, and relay alarm
signals to external systems for audible or visible alarms.) However, you can track the condition of DSL
ports on which alarms are disabled, including conditions that ordinarily trigger alarms, using the
command show dsl interface atm slot#/port#.
You can suppress minimum bit rate alarms without disabling other alarms for the profile.
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alarms
Note
Examples
The alarms command has no effect on critical alarms, major alarms, or minor alarms related to
subsystems other than the DSL subscriber ports.
In this example, the command enables alarms for the default profile:
DSLAM# configure terminal
DSLAM(config)# dsl-profile default
DSLAM(config-dsl-prof)# alarms
Related Commands
Command
Description
dsl-profile profile name
Select an existing DSL profile for modification.
show dsl interface atm slot#/port#
Display DSL, DMT, and ATM status for a port.
show dsl profile
Display a specific profile, all ports to which the profile
is currently attached, and those port settings.
show facility-alarm status
Display the current major and minor alarm status, if any,
and display the configuration of the alarm thresholds.
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dmt bitrate
dmt bitrate
To set the maximum and minimum allowed bit rates for the fast or interleaved DMT profile parameters,
use the dmt bitrate profile configuration command. To reset this command to the default value, use the
no form of this command.
dmt bitrate maximum {fast | interleaved} downstream dmt-bitrate upstream dmt-bitrate
dmt bitrate minimum {fast | interleaved} downstream dmt-bitrate upstream dmt-bitrate
Syntax Description
Defaults
dmt-bitrate
The DMT bit rate is given as a multiple of 32 kbps. If you enter a
nonmultiple of 32 kbps, the system rejects and aborts the command. See the
allowed ranges and default values in Usage Guidelines.
fast
Specify the DMT fast latency path.
interleaved
Specify the DMT interleaved latency path.
•
The default no dmt bitrate maximum interleaved sets the maximum downstream and upstream
interleaved bit rate to 640 and 128 kbps respectively. This command causes the port to retrain.
•
The default no dmt bitrate maximum fast sets both the maximum downstream and upstream
fastpath bit rates to zero. This command causes the port to retrain.
•
The default no dmt bitrate minimum interleaved sets both the minimum downstream and upstream
interleaved bit rates to zero. This command does not cause the port to retrain.
•
The default no dmt bitrate minimum fast sets both the minimum downstream and upstream fastpath
bit rates to zero. This command does not cause the port to retrain.
Command Modes
Profile configuration.
Command History
Release
Modification
12.0(5)DA
This command was introduced in a previous release.
12.1(5)DA
The fast keyword was added.
Usage Guidelines
Only the alarm subsystem uses the minimum bit rate settings. Cisco IOS asserts an alarm if the line card
trains at a rate below the configured minimum bit rate. However, no alarm occurs when you disable
alarms. See alarms in the Command Reference for Cisco DSLAMS with NI-2, for more information on
enabling and disabling alarms.
If alarms are enabled for the profile, setting the DMT bit rate to 0 disables the associated minimum DMT
bit rate alarm.
Table 2 lists the allowable DMT bit rate ranges and default values.
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dmt bitrate
Table 2
Allowable Ranges and Default Values for DMT Bit Rates
Downstream
Configuration
Parameter
Data
Path
Aggregate
Range
(kbps)
DMT bit rate max
Fast
DMT bit rate min
Upstream
Aggregate
Range
(kbps)
Path
Range
(kbps)
Path
Default
(kbps)
8064 to 32 8064 to 32 0
864 to 32
864 to 0
0
Fast
8064 to 32 8064 to 0
864 to 32
864 to 0
0
DMT bit rate max
Interleaved
8064 to 32 8064 to 32 640
864 to 32
864 to 0
128
DMT bit rate min
Interleaved
8064 to 32 8064 to 0
864 to 0
864 to 0
0
Caution
Path
Range
(kbps)
Path
Default
(kbps)
0
128
This command causes the port to retrain when you change the value of the bit rate parameter.
Setting a parameter to its current value does not cause a retrain. If a port is training when you change
the parameter, the port stops training and retrains to the new parameter.
Examples
In this example, the command sets the maximum interleaved bit rate of the default profile to 3200 kbps
downstream and 640 kbps upstream:
DSLAM# configure terminal
DSLAM(config)# dsl-profile default
DSLAM(config-dsl-prof)# dmt bitrate maximum interleaved downstream 3200 upstream 640
Related Commands
Command
Description
show dsl profile
Display a specific profile, all ports to which the profile is currently attached,
and those port settings.
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dmt check-bytes
dmt check-bytes
To set upstream and downstream FEC check (redundancy) bytes, use the dmt-checkbytes profile
configuration command. To reset this command to the default value, use the no form of this command.
dmt check-bytes {fast | interleaved} downstream bytes upstream bytes
Syntax Description
Defaults
bytes
Enter the upstream and downstream FEC check bytes. The allowed values
are 0, 2, 4, 6, 8, 10, 12, 14, and 16.
fast
Specify the DMT fast latency path.
interleaved
Specify the DMT interleaved latency path.
Downstream: 16
Upstream: 16
Command Modes
Profile configuration.
Command History
Release
Modification
12.0(5)DA
This command was introduced.
12.1(6)DA
The fast keyword was added.
Usage Guidelines
Caution
This command causes the port to retrain when you change the check-bytes parameter.
Setting a parameter to its current value does not cause a retrain. If a port is training when you change
the parameter, the port untrains and retrains to the new parameter.
Conditions on the line, the configured bit rate, and the capabilities of the ATU-R CPE affect the
achievable value for this parameter. As a result, the check-bytes value to which the line trains may be
smaller than the value you configure. If you want to use more check bytes than the system is allowing
you, use the dmt bitrate command to reduce the bit rate.
Use the command show dsl interface atm slot#/port# to display the configured and actual check-bytes
values for the connection.
Examples
In this example, the command sets the interleaved FEC check-bytes for the default profile to
12 downstream and 6 upstream.
DSLAM# configure terminal
DSLAM(config)# dsl-profile default
DSLAM(config-dsl-prof)# dmt check-bytes interleaved downstream 12 upstream 6
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dmt check-bytes
Related Commands
None.
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dmt margin
dmt margin
To set upstream and downstream signal-to-noise ratio (SNR) margins for a DMT profile, use the dmt
margin command. To reset this command to the default value, use the no form of this command.
dmt margin downstream dmt-margin upstream dmt-margin
Syntax Description
dmt-margin
Defaults
Downstream: 6 dB
Enter the upstream and downstream SNR margins in decibels. The range is
0 to 15.
Upstream: 6 dB
Command Modes
Profile configuration.
Command History
Release
Modification
12.0(5)DA
This command was introduced.
Usage Guidelines
Caution
This command causes the port to retrain when you change the parameter.
Setting a parameter to its current value does not cause a retrain. If a port is training when you change
this value, the port untrains and retrains to the new value.
Examples
In this example, the command sets the SNR margins of the default profile to 12 dB downstream and
6 dB upstream:
DSLAM# configure terminal
DSLAM(config)# dsl-profile default
DSLAM(config-dsl-prof)# dmt margin downstream 12 upstream 6
Related Commands
None.
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dmt minrate-blocking
dmt minrate-blocking
To force a port not to retrain when actual bit rates fall below the values configured in the dmt bitrate
minimum command, use the dmt minrate-blocking command. To disable dmt minrate-blocking, use
the no form of the command.
dmt minrate-blocking
Syntax Description
This command has no arguments or keywords.
Defaults
The default configuration, no dmt minrate-blocking, generates a minor alarm when the bit rates on a
DMT port violate the minimum allowed bit rates specified in the dmt bitrate minimum command
(if alarms are enabled in the DSL profile).
Command Modes
DSL profile configuration.
Command History
Release
Modification
IOS 12.1(6)DA
This command was introduced.
Usage Guidelines
To specify the bit rate below which a DMT port will not retrain, use the dmt bitrate
minimum command.
Examples
The following example describes how to enable dmt minrate-blocking:
configure terminal
dsl-profile 8xDMT
dmt minrate-blocking
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dmt overhead-framing
dmt overhead-framing
To set the overhead framing mode, use the dmt overhead-framing command.To reset this command to
the default value, use the no form of this command.
dmt overhead-framing {mode0 | mode1 | mode2 | mode3}
Syntax Description
mode0
Full overhead framing with asynchronous bit-to-modem timing.
mode1
Full overhead framing with synchronous bit-to-modem timing.
mode2
Reduced overhead framing with separate fast and sync bytes in the fast and
interleaved latency buffers respectively.
mode3
Reduced overhead framing with merged fast and sync bytes, using either the
fast or interleaved latency buffer.
Defaults
Mode3.
Command Modes
Profile configuration.
Command History
Release
Modification
12.0(5)DA
This command was introduced.
12.1(6)DA
Mode 0 was added.
Usage Guidelines
Note
Conditions on the line and the capabilities of the ATU-R CPE affect the achievable value for this
parameter. As a result, the overhead framing value to which the line trains may not be the same as
the value you configure.
There are two types of ADSL framing:
•
Full overhead
•
Reduced overhead
There are also two versions of full overhead:
•
Asynchronous
•
Synchronous
You select the type of ADSL framing by choosing one of four modes:
•
Mode 0—Full overhead framing with asynchronous bit-to-modem timing (an enabled
synchronization control mechanism).
•
Mode 1—Full overhead framing with synchronous bit-to-modem timing (a disabled synchronization
control mechanism).
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dmt overhead-framing
•
Mode 2—Reduced overhead framing with separate fast and sync bytes in the fast and interleaved
latency buffers respectively.
•
Mode 3—Reduced overhead framing with merged fast and sync bytes using either the fast or
interleaved latency buffer.
Mode 3 is recommended for use on DMT interfaces adhering to the ANSI T1.413 Issue 2 standard.
Mode 3 is required for flexi line card DMT interfaces.
Note
The number of overhead bytes per frame varies according to the overhead framing mode and the
operating mode, as shown in Table 3.
Table 3
Overhead Bytes per Frame
Overhead Bytes
T1.413 and G992.1
G992.2
Framing Mode
Downstream
Upstream
Downstream
Upstream
Mode 0
4
3
N/A
N/A
Mode 1
3
3
N/A
N/A
Mode 2
2
2
N/A
N/A
Mode 3
1
1
1
1
If, during the training sequence, the ATU-R indicates a lower framing structure than that specified by the
ATU-C, the ATU-C falls back to the framing structure number indicated by the ATU-R.
Management requirements drive the determination of overhead, full or reduced. Full overhead provides
more bandwidth to the embedded operations channel (EOC), enabling higher polling rates. However,
reduced overhead provides enough EOC bandwidth to satisfy typical applications.
The dmt overhead-framing command does not cause port retrain when you change the parameter.
Examples
In this example, the command sets the overhead framing mode in the profile named 8xDMT.
DSLAM# configure terminal
DSLAM(config)# dsl-profile 8xDMT
DSLAM(config-dsl-prof)# dmt overhead-framing mode2
Related Commands
Command
Description
show dsl profile
Display a specific profile, all ports to which the profile is currently attached,
and those port settings.
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dmt rate-adaptation enable
dmt rate-adaptation enable
DMT rate adaptation monitors upstream and downstream DMT ports for signal-to-noise ratio (SNR)
margins during specified time intervals. If an unacceptable SNR margin is detected, the port is retrained
at a lower bit rate to improve the SNR margins. To enable rate adaptation on a DMT port, use the
dmt rate-adaptation enable command at the DSL profile configuration prompt. To disable dmt rate
adaptation, use the no form of the command.
dmt rate-adaptation enable
This command has no arguments or keywords.
Defaults
Enabling dmt rate-adaptation configures the commands dmt rate-adaptation interval and
dmt rate-adaptation margin with their default values. For information on the default values of
dmt rate-adaptation interval and dmt rate-adaptation margin see the “dmt rate-adaptation interval”
section on page 22 and the “dmt rate-adaptation margin” section on page 24.
Command Modes
DSL profile configuration
Command History
Release
Modification
IOS 12.1(6)DA
This command was introduced.
Usage Guidelines
If you wish to modify the default configuration of the dmt rate-adaptation interval and
dmt rate-adaptation margin see the “dmt rate-adaptation interval” section on page 22 and the “dmt
rate-adaptation margin” section on page 24.
Examples
The following example enables dmt rate-adaptation with default interval and margin values:
config terminal
dsl-profile austin
dmt rate-adaptation enable
Related Commands
Command
Description
dmt rate-adaptation interval
Sets the upstream and downstream time intervals at which a DMT
port is monitored for SNR margins.
dmt rate-adaptation margin
Sets the SNR values below which the DMT port retrains to a lower
bit rate.
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dmt rate-adaptation interval
dmt rate-adaptation interval
To change the intervals during which a DMT port is monitored for signal-to-noise ratio (SNR) margins,
use the dmt rate adaptation interval command in DSL profile configuration mode. To disable
dmt rate adaptation interval, use the no form of this command.
dmt rate-adaptation interval {downshift [downstream number-of eoc-updates
upstream seconds]}
Syntax Description
downshift
The downshift keyword indicates that a line with excessive SNR margins retrains
to a lower bit rate.
downstream
The downstream keyword tells IOS to monitor downstream ports for SNR margins
exceeding those specified in the dmt rate-adaptation margin command.
number-of
eoc-updates
The number-of eoc-updates argument specifies the monitoring interval in multiples
of six seconds on a downstream DMT port.
Note
Defaults
The downstream margin (see “dmt rate-adaptation margin” section on
page 24) is obtained from the CPE via the embedded operations channel
(EOC). The downstream number-of eoc-updates parameter specifies a
number of consecutive EOC read events. Depending upon the type of CPE,
EOC messages are sent once every 6 to 15 seconds (not counting EOC
timeouts). Hence, a downstream downshift interval value of 10 on CPE
reporting margins every 6 seconds results in a 1 minute monitoring interval
(10x6 seconds). Specifying a downstream downshift interval value of 10 on
CPE that report margins every 15 seconds (10x15 seconds) yields a 2.5
minute monitoring interva1.
upstream
The upstream keyword tells IOS to monitor upstream ports for SNR margins
exceeding those specified in the dmt rate-adaptation margin command.
seconds
The seconds argument specifies the monitoring interval in seconds on an upstream
DMT port.
Following are the default settings for the dmt rate adaptation interval:
•
Note
•
downstream—10
Remember, a downstream value of 10 can yield a monitoring interval between 1 minute to
2.5 minutes in length.
upstream—10
Command Modes
DSL profile configuration
Command History
Release
Modification
IOS 12.1(6)DA
This command was introduced.
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dmt rate-adaptation interval
Usage Guidelines
Note
Examples
Use the dmt rate-adaptation interval to specify the frequency at which line margins are checked on a
DMT port. The dmt rate-adaptation interval command works in conjunction with the
dmt rate-adaptation margin command. If the actual SNR margins on a port remain lower than the
margins configured in the dmt rate-adaptation margin command, for the duration of time specified in
the dmt rate-adaptation interval command, the line drops and retrains to a lower bit rate, to improve
SNR margin quality on the line.
If line conditions improve, the line does not automatically drop and retrain to a higher bit rate. If the
line conditions improve, the administrator must execute a shut then a no shut on the port to retrain
to a higher bit rate.
The following example configures a downstream monitoring interval of roughly 60 to 150 seconds. The
upstream monitoring interval is 20 seconds.
config terminal
dsl-profile austin
dmt rate-adaptation interval downshift downstream 10 upstream 20
Related Commands
Command
Description
dmt rate-adaptation enable
Turns on rate adaptation.
dmt rate-adaptation margin
Sets the SNR margins below which a DMT port retrains to a lower
bit rate.
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dmt rate-adaptation margin
dmt rate-adaptation margin
To configure the minimum acceptable SNR margins on a DMT port, which force the port to retrain when
bad margins exist for the duration of the dmt rate-adaptation interval, use the dmt rate adaptation
margin command in DSL profile configuration mode. To disable dmt rate adaptation margin use the
no form of this command.
dmt rate-adaptation margin {min [downstream dB upstream dB]}
Syntax Description
min
The min keyword specifies that you are configuring the minimum
acceptable SNR margins on a port. If the port SNR exceeds the configured
value, the port retrains to a lower bit rate.
downstream
Specifies the minimum acceptable SNR margin for downstream traffic on
a port.
dB
SNR margins measured in decibels. The valid range is –15 to 15.
upstream
Specifies the minimum acceptable SNR margin for upstream traffic on
a port.
dB
SNR margins measured in decibels. The valid range is -15 to 15.
Defaults
The default configuration is derived from the no dmt rate-adaptation enable command. This specifies
minimum upstream and downstream SNR margins of 0 dB.
Command Modes
DSL profile configuration
Command History
Release
Modification
IOS 12.1(6)DA
This command was introduced.
Usage Guidelines
Note
Use the dmt rate-adaptation margin command to configure the acceptable SNR margin thresholds on
a specified port. The dmt rate-adaptation margin command works in conjunction with the
dmt rate-adaptation interval command. If the actual SNR margins on a port remain lower than the
margins configured in the dmt rate-adaptation margin command, for the duration of time specified in
the dmt rate-adaptation interval command, the line drops and retrains to a lower bit rate, to improve
SNR margin quality on the line.
If line conditions improve, the line does not automatically drop and retrain to a higher bit rate. If the
line conditions improve, the administrator must execute a shut then a no shut on the affected port to
retrain to a higher bit rate.
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slot
slot
To provision a slot for a specific card type, or to change the line coding for a flexi line card, use the
slot command.
slot slot# cardtype
Syntax Description
slot#
The number of the slot you want to provision. The range is 1 to 38.
The number of slots varies by chassis. The Cisco 6130 has
38 slots, the Cisco 6160 has 34 slots, and the Cisco 6260 has
32 slots.
Note
cardtype
The line card type for which you want to configure the slot. The
valid card types are
•
ATUC-1-4DMT—4-port DMT card
•
ATUC-1-4DMT-I—4-port DMT over ISDN card
•
ATUC-4FLEXICAP—4-port flexi card configured as CAP
•
ATUC-4FLEXIDMT—4-port flexi card configured as DMT
•
ATUC-1-DMT8—8-port DMT card
•
ITUC-1-8IDSL—8-port IDSL card
•
STUC-4-2B1Q-DIR-1—4-port SDSL card
Note
Some line cards do not function in all NI-2 DSL systems.
For example, the Cisco 6100 system supports only a
dual-port CAP ATU-C line card. Consult the hardware
documentation for your DSL system to determine which line
cards it supports.
Defaults
None.
Command Modes
Global configuration.
Command History
Release
Modification
12.0(5)DA
This command was introduced.
12.1(1)DA
New card types were added.
12.1(6)DA
New card types were added.
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slot
Usage Guidelines
Use the slot command to provision a slot for a line card.
Card mismatch error conditions include the following:
•
A line card is already installed in the specified slot
•
The specified slot contains one type of card but is provisioned for another type
If you attempt to provision an empty slot, the major alarm “MODULE-MISSING” asserts.
The 8xDMT line card is spectrally incompatible with both the 8-port IDSL line card and the 4-port SDSL
(STU-C) line card. If you install spectrally incompatible cards in the same chassis, the lines served by
those cards can suffer reduced performance. For best performance in a chassis with a mixture of line card
types, always install 8xDMT line cards on one side of the chassis and install IDSL and SDSL cards on
the opposite side.
Examples
The command in this example provisions slot 30 for an 8xDMT line card.
DSLAM# configure terminal
DSLAM(config)# slot 30 ATUC-1-DMT8
Related Commands
Command
Description
show hardware
Display information about the physical modules in the chassis.
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Glossary
Glossary
A
ADSL
Asymmetric Digital Subscriber Line. A digital subscriber line (DSL) technology in which the
transmission of data from server to client is much faster than the transmission from the client to
the server.
ADSL Transmission
Unit—central office
See ATU-C.
ADSL Transmission
Unit—remote
See ATU-R.
asymmetric digital
subscriber line
See ADSL.
Asynchronous
Transfer Mode
See ATM.
ATM
Asynchronous Transfer Mode. A cell-based data transfer technique in which channel demand
determines packet allocation. ATM offers fast packet technology, real time, demand led switching for
efficient use of network resources.
ATU-C
ADSL Transmission Unit—central office.
ATU-R
ADSL Transmission Unit—remote.
C
CBOS
Cisco Broadband Operating System. Operating System that users access to configure and operate the
Cisco products.
CCO
Cisco Connection Online.
chassis
The card cage (housing) where modules are placed.
Cisco Connection
Online
See CCO.
CLI
Command Line Interface.
CPE
customer premises equipment.
CTC
Common Transmit Clock.
D
DMT
Discrete Multitone.
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Glossary
Cisco Distributed Defect Tracking System.
DDTS
digital signal level 3 See DS3.
Distributed Defect
Tracking System
See DDTS.
DS3
digital signal level 3. Framing specification used for transmitting digital signals at 44.736 Mbps on a
T3 facility.
DSLAM
Digital Subscriber Line Access Multiplexer. Concentrates and multiplexes digital subscriber line
signals at the telephone service provider location to the broadband wide area network.
Replaces ADSLAM.
F
frame
A packet as it is transmitted over a serial line. The term derives from character oriented protocols
where special start-of-frame and end-of-frame characters were added when transmitting packets.
FTP
File Transfer Protocol. The Internet protocol (and program) used to transfer files between hosts.
G
G.992.2
The ITU standard for line coding and framing for splitterless, reduced spectrum ADSL. Also known
as G.lite.
G.994.1
The ITU standard for signalling, identification, and negotiation between broadband systems; an
integral part of G.dmt and G.lite. Also known as G.hs.
G.997.1
The ITU standard for performance monitoring on DMT access technologies.
G.dmt
Pseudonym for G.992.1.
G.hs
Pseudonym for G.994.1. HandShake (hs)
G.lite
Pseudonym for G.992.2
H
Handshake
Part of the procedure to set up a data communications link. The handshake can be part of the
protocol itself or an introductory process. The computers wishing to talk to each other set out the
conditions they can operate under. Sometimes, the handshake is just a warning that a communication
is imminent.
I
Internet Protocol. The network layer protocol for the Internet Protocol suite.
IP
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Glossary
IP address
The 32-bit address assigned to hosts that want to participate in a TCP/IP Internet.
ITU
The International Telecommunications Union; a telecommunications standards body.
L
LCD
Loss of Cell Delineation
LODS
Loss Of Delay Synchronization
LOF
Loss Of Frame.
loopback
A diagnostic test that returns the transmitted signal back to the sending device after it has passed
through a network or across a particular link. The returned signal can then be compared to the
transmitted one. The discrepancies between the two help to trace the fault. When trying to locate a
faulty piece of equipment, loopbacks will be repeated, eliminating satisfactory machines until the
problem is found.
LOS
loss of signal.
M
Management
Information Base
See MIB.
MIB
Management Information Base. A collection of objects that can be accessed via a network
management protocol, such as SNMP and CMIP (Common Management Information Protocol).
N
NI-2
A second generation network interface card.
P
PVC
Stands for permanent virtual connection. A fixed virtual connection between two users: The public
data network equivalent of a leased line. No call setup or clearing procedures are needed.
R
route
The path that network traffic takes from its source to its destination. The route a datagram may
follow can include many gateways and many physical networks. In the Internet, each datagram is
routed separately.
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Glossary
router
A system responsible for making decisions about which of several paths network (or Internet) traffic
will follow. To do this, it uses a routing protocol to gain information about the network and algorithms
to choose the best route based on several criteria known as “routing metrics.” See also bridge.
routing table
Information stored within a router that contains network path and status information. It is used to
select the most appropriate route to forward information along.
S
Simple Network
Management
Protocol
See SNMP.
slot
A numbered location within a chassis capable of housing a module.
SNMP
Simple Network Management Protocol. The network management protocol of choice for
TCP/IP-based internets.
SVC
Stands for switched virtual connection. A temporary virtual connection between two users.
T
TCP
Transmission Control Protocol. The major transport protocol in the Internet suite of protocols
providing reliable, connection-oriented full-duplex streams.
T1.413
The ANSI standard for line coding and framing for full rate ADSL.
Telnet
The virtual terminal protocol in the Internet suite of protocols. Allows users of one host to log into a
remote host and act as normal terminal users of that host.
TFTP
Trivial File Transfer Protocol. A simple file transfer protocol (a simplified version of FTP) that is often
used to boot diskless workstations and other network devices such as routers over a network (typically
a LAN). Has no password security.
training
The procedure used by the ATU-C and ATU-R to establish an end-to-end ADSL connection.
training mode
Characteristic of a router that allows it to use RADSL technology to adjust its line speed according to
noise conditions on the transmission line.
Transmission
Control Protocol
See TCP.
Trivial File Transfer
Protocol
See TFTP.
trellis encoding
A channel coding technique which provides forward error correction capability.
twisted pair
Two insulated copper wires twisted together with the twists or lays varied in length to reduce potential
signal interference between the pairs.
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Glossary
U
upstream rate
The line rate for message or data transfer from the source machine to a destination machine on the
network. Also see downstream rate.
V
VC
Virtual circuit. A logical circuit created to ensure reliable communication between two network
devices. A virtual circuit is defined by a VPI/VCI pair, and can be either permanent (PVC) or switched
(SVC). In ATM, a virtual circuit is called a virtual channel. Sometimes abbreviated VC. See also PVC,
SVC, VCI, and VPI.
virtual circuit
See VC.
VCI
Virtual channel identifier. A 16-bit field in the header of an ATM cell. The VCI, together with the VPI,
is used to identify the next destination of a cell as it passes through to the ATM switch. Sometimes
called virtual channel connection. See also VPI.
VPI
Virtual path identifier. An 8-bit field in the header of an ATM cell. The VPI, together with the VCI, is
used to identify the next destination of a cell as it passes through the network. See also VCI.
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Glossary
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