Cabletron Systems TRMIM-10R Installation Manual
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TRMIM-10R
TOKEN RING
MEDIA INTERFACE MODULE
INSTALLATION GUIDE
The Complete Networking Solution
CABLETRON SYSTEMS, P. O. Box 5005, Rochester, NH 03867-5005
NOTICE
NOTICE
Cabletron Systems reserves the right to make changes in specifications and other information contained in this document without prior notice. The reader should in all cases consult Cabletron Systems to determine whether any such changes have been made.
The hardware, firmware, or software described in this manual is subject to change without notice.
IN NO EVENT SHALL CABLETRON SYSTEMS BE LIABLE FOR
ANY INCIDENTAL, INDIRECT, SPECIAL, OR CONSEQUENTIAL
DAMAGES WHATSOEVER (INCLUDING BUT NOT LIMITED TO
LOST PROFITS) ARISING OUT OF OR RELATED TO THIS MAN-
UAL OR THE INFORMATION CONTAINED IN IT, EVEN IF
CABLETRON SYSTEMS HAS BEEN ADVISED OF, KNOWN, OR
SHOULD HAVE KNOWN, THE POSSIBILITY OF SUCH DAM-
AGES.
Copyright November 1990 by:
Cabletron Systems, Inc.
P.O. Box 5005, Rochester, NH 03867-5005
All Rights Reserved
Printed in the United States of America
Order Number: 9030258 November 90
LANVIEW, Remote LANVIEW Windows, Spectrum,
TRMIM-10R, TRRMIM-16, TRMIM-12, MMAC, and FNB are trademarks of Cabletron Systems Inc.
IBM is a registered trademark of International Business Machines
Corporation.
i
FCC NOTICE
FCC NOTICE
This device complies with Part 15 of FCC rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.
WARNING: This equipment uses and generates and can radiate radio frequency energy and if not installed properly and used in accordance with the instruction manual, may cause interference to radio communications. It has been tested and found to comply with the limits for a Class A digital device pursuant to Part 15 of FCC
Rules, which are designed to provide reasonable protection against such interference in a commercial environment. Operation of this equipment in a residential area is likely to cause interference in which case the user at his own expense will be required to take whatever steps may be necessary to correct the interference.
If this equipment does cause interference to radio or television, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:
• Re-orient the receiving antenna.
• Relocate the MMAC with respect to the receiving antenna.
• Move the MMAC away from the receiver.
• Plug the MMAC into a different outlet so that the MMAC and the receiver are on different branch circuits.
If necessary, the user should consult the dealer or an experienced radio/television technician for additional suggestions. The user may find the following booklet prepared by the Federal Communication
Commission helpful:
“How to Identify and Resolve Radio TV Interference Problems”
This booklet is available from the U.S. Government Printing Office,
Washington D.C. 20402 - Stock No. 004-000-00345-4 ii
CONTENTS
CONTENTS
CHAPTER PAGE
CHAPTER 1 INTRODUCTION
1.1 Using This Manual ......................................................................1-1
1.2 The TRMIM-10R ..........................................................................1-2
1.3 Related Manuals ..........................................................................1-4
1.4 Recommended Reading ................................................................1-4
1.5 Getting Help .................................................................................1-4
CHAPTER 2 INSTALLATION REQUIREMENTS/
SPECIFICATIONS
2.1 Network Requirements ................................................................2-1
2.1.1 Cable Types ........................................................................2-1
2.1.2 Cable Lengths .....................................................................2-2
2.1.3 Attenuation .........................................................................2-3
2.1.4 Impedance ...........................................................................2-4
2.1.5 Crosstalk .............................................................................2-4
2.1.6 Maximum Number of Stations ..........................................2-4
2.1.7 Noise ...................................................................................2-5
2.1.8 Temperature .......................................................................2-5
2.2 Operating Specifications ..............................................................2-5
2.2.1 Ring Speed ..........................................................................2-5
2.2.2 Connector Types .................................................................2-5
2.2.3 Ring Sequence ....................................................................2-7
2.2.4 LANVIEW LEDs ................................................................2-7
CHAPTER 3 INSTALLING THE TRMIM-10R
3.1 Unpacking the TRMIM-10R ........................................................3-1
3.2 Installing the TRMIM-10R into the MMAC ...............................3-1
3.3 Attaching Cables to the TRMIM-10R ......................................... 3-4
3.3.1 Connecting Lobe Cabling ...................................................3-4
3.3.2 Connecting Trunk Cabling ................................................ 3-6
3.4 Finishing the Installation ............................................................ 3-7 iii
CONTENTS
CONTENTS
(Cont.)
CHAPTER 4 TESTING AND TROUBLESHOOTING
4.1 Installation Check-Out ................................................................4-1
4.2 Using LANVIEW .........................................................................4-2
APPENDIX A BASIC TOKEN RING NETWORKS
A.1 Basic Token Ring Operation .......................................................A-1
A.2 Design Considerations .................................................................A-7
APPENDIX B APPLICATIONS
B.1 Adding to an Existing Token Ring Network ............................. B-1
B.2 Separate Token Ring Networks in One MMAC .......................B-2
B.3 Token Ring Networks Bridged Together .................................. B-3
B.4 MMAC with Ethernet and Token Ring Simultaneously .......... B-3
APPENDIX C CALCULATING RING LENGTH
C.1 Rules for Calculating Cable Lengths ........................................C-1
C.2 Single Wiring Closet Networks .................................................C-2
C.3 Multiple Wiring Closet Networks .............................................C-9
C.4 Calculating Mixed Cable Types ...............................................C-15 iv
INTRODUCTION
CHAPTER 1
INTRODUCTION
Welcome to the TRMIM-10R Token Ring Passive Concentrator
Media Interface Module
Installation Guide. This guide is designed to serve as a reference for the installation and troubleshooting of Cabletron Systems' TRMIM-10R.
The TRMIM-10R is a token ring network concentrator used in conjunction with Cabletron's Multi Media Access Center (MMAC).
The TRMIM-10R provides ten trunk unit coupling ports and passive
Ring-In and Ring-Out ports. The Ring-In/Ring-Out ports and each of the TRMIM-10R's ten trunk coupling unit ports support IBM
Types
1, 2, 6, and 9 shielded twisted pair cabling. The TRMIM-10R is IEEE
802.5 compliant, and compatible with IBM products.
Prior to installing and operating the TRMIM-10R, read through this manual completely to familiarize yourself with its content and to gain an understanding of the features of the TRMIM-10R. A general working knowledge of token ring (IEEE 802.5) networks will be helpful when installing the TRMIM-10R.
1.1 USING THIS MANUAL
Chapter 1, Introduction, covers using this document, briefly describes features of the TRMIM-10R and token ring, and concludes with a list of related manuals.
Chapter 2, Installation Requirements/Specifications, lists network requirements that must be met before you install the
TRMIM-10R and specifications for the TRMIM-10R.
Chapter 3, Installing the TRMIM-10R, describes installing the
TRMIM-10R into the MMAC, attaching station cabling and connecting the TRMIM-10R to a token ring network.
Chapter 4, Testing and Troubleshooting, includes a description of
LANVIEW
, Cabletron Systems' built-in visual diagnostic and status monitoring system and procedures for verifying the proper installation of the TRMIM-10R.
Page 1-1
INTRODUCTION
Appendix A, Basic Token Ring Networks, covers basic operation and concepts related to the design of token ring networks.
Appendix B, Applications, presents a variety of network configurations, showing practical applications for several Cabletron
Systems' token ring products.
Appendix C, Calculating Ring Length, describes methods for calculating various ring cable lengths for passive devices in a token ring network.
1.2 THE TRMIM-10R
This section outlines some of the basic features of the TRMIM-10R.
The TRMIM-10R, shown in Figure 1-1, is a Media Interface Module
(MIM) that can be installed into a Cabletron Systems' MMAC (Multi
Media Access Center). The TRMIM-10R functions as a ten port concentrator module in a token ring network providing passive Ring-
In and Ring-Out ports and ten trunk coupling ports.
Twelve DB-9 connectors on the front panel of the TRMIM-10R provide one Ring-In port, one Ring-Out port for connecting the
TRMIM-10R into a token ring network and ten trunk coupling ports for attaching ten stations.
The TRMIM-10R supports lobe lengths up to 200 meters at 4 Mbit/sec and 100 meters at 16 Mbit/sec using IBM Type 1 or Type 2 shielded twisted pair cable. The supported types and lengths of cables are listed in Chapter 2, Installation Requirements/Specifications.
The Ring-In/Ring-Out ports provide passive trunk connections using
IBM Type 1 or Type 2 shielded twisted pair cable. Trunk cable lengths must consider Adjusted Ring Length (ARL). Refer to
Appendix C, Calculating Ring Length, to determine trunk cable length.
The Flexible Network Bus (FNB
) provides an internal trunk connection between multiple Cabletron Systems' Token Ring products operating at the same ring speed and installed in consecutive slots within the same MMAC. The FNB is an active interface that regenerates and retimes ring signals between boards on the FNB.
Page 1-2
INTRODUCTION
Several LEDs are located on the front panel of the TRMIM-10R.
These LEDs indicate the ring speed, the detection of a hardware error in the TRMIM-10R, and the status of TRMIM-10R ports. These
LEDs are a useful tool for quickly diagnosing physical layer problems.
A variety of network manangment tools can be used to control and monitor the TRMIM-10R, including Cabletron Systems Local
Management, Cabletron Systems Remote LANVIEW Windows
, and
Cabletron Systems Spectrum
.
TRMIM-10R
7
8
9
3
10
4
RI
5
RO
TOKEN RING
6
1
2
Figure 1-1. TRMIM-10R Token Ring Concentrator
Page 1-3
INTRODUCTION
1.3 RELATED MANUALS
The manuals listed below should be used to supplement the procedures and other technical data provided in this manual. The procedures in them will be referenced, where appropriate, but will not be repeated in this document.
Cabletron Systems' Multi-Media Access Center Overview and
Set Up Guide.
Cabletron Systems' TRMIM-12 Token Ring Media Interface
Module Installation Guide.
Cabletron Systems' TRRMIM-16 Token Ring Repeater Media
Interface Module Installation Guide.
1.4 RECOMMENDED READING
The following publications are recommended if more information is required on implementing a Token Ring network.
Local Area Networks, Token Ring Access Method, IEEE
Standard 802.5
LAN Troubleshooting Handbook, Mark Miller (1989, M&T
Publishing, Inc.)
1.5 GETTING HELP
If you need additional support related to the Cabletron Systems' token ring products, or if you have any questions, comments or suggestions related to this manual, please contact Cabletron Systems'
Technical Support at:
Cabletron Systems
35 Industrial Way
P. O. Box 5005
Rochester, NH 03867-5005
Phone: (603) 332-9400
Page 1-4
REQUIREMENTS/SPECIFICATIONS
CHAPTER 2
INSTALLATION REQUIREMENTS/
SPECIFICATIONS
Before you attempt to install Cabletron Systems' token ring products, review the installation requirements and operating specifications outlined in this chapter. The conditions, guidelines and requirements described in this chapter must be met to obtain satisfactory performance from this equipment. The reliability of the network is determined by the quality of the connections, the length of the cables and other conditions of the installation.
2.1 NETWORK REQUIREMENTS
The following subsections summarize the network requirements to operate this equipment.
2.1.1 Cable Types
The TRMIM-10R supports IBM shielded twisted pair cable Types 1,
2, 6, and 9 for Lobe and Trunk cabling. Table 2-1 lists all of the IBM cable types for reference, but the TRMIM-10R supports Types 1, 2, 6, and 9 only.
Table 2-1. IBM Cable Types
Type 1 Two shielded twisted pairs (STP) of 22 AWG solid wire for data. Used for the longest cable runs within the walls of buildings.
Type 2 Similar to Type 1 data cable, but having four additional unshielded twisted pairs of 24 AWG solid wire. These are carried outside of the shield casing and are typically used for voice communication. Frequently used to wire cable runs within the walls of buildings.
Page 2-1
REQUIREMENTS/SPECIFICATIONS
Table 2-1 (cont.). IBM Cable Types
Type 3 Usually four unshielded twisted pairs (UTP) of 24 AWG solid wire for data or voice communication. Used for cable runs in walls of buildings.
Type 5 Two 100/140
µ m optical fibers in a single sheath.
Type 6 Two STP of 26 AWG stranded wire for data. This type is used in patch panels or to connect devices to/from wall jacks. Attenuation for Type 6 cable is 3/2 x Type 1 cable
(66 m of Type 6 = 100 meters of Type 1).
Type 8 One flat STP of 26 AWG stranded wire for under carpet installation.
Type 9 Similar to Type 1, but uses 26 AWG solid wire.
Attenuation for Type 9 cable is 3/2 x Type 1 cable (66 m of Type 9 = 100 meters of Type 1).
2.1.2 Cable Lengths
The TRMIM-10R is a passive concentrator. It neither regenerates nor retimes ring signals and the cable lengths used for the TRMIM-
10R must consider the Adjusted Ring Length (ARL). ARL results from automatic recovery processes that attempt to restore continuity to a broken ring. The ARL is the longest potential ring length, the ring that would exist following recovery from a failure of the shortest ring segment trunk cable. Refer to the discussion of token ring concepts related to ARL in Appendix A. Appendix C describes how to calculate cable lengths in your network, giving consideration to ARL.
Considering ARL, two cable lengths must be defined for the TRMIM-
10R: Lobe Length and Trunk Length. Their combined length defines the path between two token ring stations and cannot exceed the maximum drive distance.
• Drive Distance - Drive distance is the limit of reliable signal propagation without the installation of repeaters in the ring. The maximum drive distance using STP cabling is 770 meters (2525 feet) at 4 Mbit/sec and 346 meters (1138 feet) at 16 Mbit/sec.
These limits include the combined length of all trunk cables plus twice the length of the longest lobe cable.
Page 2-2
REQUIREMENTS/SPECIFICATIONS
• Lobe Length - This is the physical length of STP cable connecting a station to the trunk coupling unit (TCU) port on the
TRMIM-10R. The recommended maximum length for the longest lobe cable is shown in Table 2-2. This is a recommended maximum because cable length calculations for passive ring connections described in Appendix C could produce a maximum lobe length for your network that differs from this limit.
Installing a lobe that exceeds the recommended maximum could restrict future expansion of the network.
• Trunk Length - This is the physical length of the STP cabling in the main ring path, from Ring-Out to Ring-In on each of the attached token ring devices. The cable budget for the trunk cabling must be determined by performing the calculations described in Appendix C. In a totally passive ring (no repeaters or active concentrators, etc. on the ring), the entire trunk length must be included in calculation of cable lengths. When only a portion of the ring is passive, the combined length of the trunk cabling between the active components must be considered in the cable length calculations.
STP (IBM Types 1 & 2)
STP (IBM Type 6)
(only for station to wall jack and patch panels)
STP (IBM Type 9)
Table 2-2. Lobe Cabling
Maximum Lobe Length
4 Mbit/sec 16 Mbit/sec
200 meters 100 meters
30 meters 30 meters
130 meters 65 meters
2.1.3 Attenuation
Maximum attenuation for specific cable types according to ring speed, is shown by Table 2-3. Since there are two possible ring speeds, two frequencies are listed, namely 4.0 MHz and 16 MHz. The attenuation values include the attenuation of the cables, connectors, and patch panels.
Page 2-3
REQUIREMENTS/SPECIFICATIONS
Table 2-3. Maximum Cable Attenuation
4.0 MHz
STP (IBM Types 1 & 2) 22 dB/km
STP (IBM Types 6 & 9) 33 dB/km
16.0 MHz
45 dB/km
66 dB/km
2.1.4 Impedance
The characteristic impedances for specific cable types are listed in
Table 2-4. These are typical impedances, and can vary among different manufacturers of cabling.
Table 2-4. Cable Impedance
Cable Type Characteristic Impedance
STP (IBM Types 1 & 2) 150 ohms (1 MHz to 20 MHz)
±
10%
STP (IBM Types 6 & 9) 150 ohms (1 MHz to 20 MHz)
±
10%
2.1.5 Crosstalk
Crosstalk is caused by signal coupling between the different cable pairs contained within a multi-pair cable bundle. In shielded twisted pair cables, the effects of crosstalk are minimized.
2.1.6 Maximum Number of Stations
Table 2-5 shows the maximum number of stations that can be inserted into a single ring using STP cabling according to ring speed.
Table 2-5. Maximum Number of Stations
4 Mbit/sec 16 Mbit/sec
Number of Stations 250 stations 136 stations
NOTE: If unshielded twisted pair (UTP) cabling is used with
STP in the same ring, the number of stations is determined by the UTP specification.
Page 2-4
REQUIREMENTS/SPECIFICATIONS
2.1.7 Noise
Noise can be caused by either crosstalk or externally induced impulses. If noise induced errors are suspected, it may be necessary to re-route cabling away from potential noise sources (motors, switching equipment, high amperage equipment), or to ensure that the electrical wiring in the area is properly wired and grounded.
2.1.8 Temperature
The attenuation of PVC insulated cable varies significantly with temperature. At temperatures greater than 40
°
C, we strongly recommend that you use plenum-rated cables to ensure that cable attenuation remains within specification. Check the cable manufacturer's specifications.
2.2 OPERATING SPECIFICATIONS
This section includes the operating specifications for the TRMIM-10R.
Cabletron Systems Inc. reserves the right to change these specifications at any time without notice.
2.2.1 Ring Speed
The TRMIM-10R can be operated at a ring speed of either 4 Mbit/sec or 16 Mbit/sec. The default ring speed is set by a hardware jumper on the TRMIM-10R. The ring speed can be changed via a software selection (refer to the applicable Remote LANVIEW Network
Management Users Guide) that overrides the jumper selection.
2.2.2 Connector Types
• Trunk Coupling Unit Ports - Ten Female DB-9 connectors are located on the front panel of the TRMIM-10R. They are labeled 1 through 10, corresponding to the ten Trunk Coupling Unit (TCU) ports. Figure 2-1 shows the pin layout and signal connections for these connectors.
Page 2-5
REQUIREMENTS/SPECIFICATIONS
TCU Ports: Pin Pin Pin
1 TX–
2 Ground
3 Not Used
4 Ground
5 RX–
6 TX+
TCU PORT
FEMALE DB-9 RECEPTACLE
TX1
Common Ground 2
Not Connected
Common Ground
RX5
3
4
6 TX+
7
Common
Ground
8
9 RX+
Figure 2-1. TCU Ports Pinouts
7 Ground
8 Ground
9 RX+
• Trunk Connections - Two Female DB-9 connectors for attaching STP trunk cables are located on the lower left side of the TRMIM-10R front panel. Figure 2-2 show the signal and pin assignments for the STP ring interface.
Trunk Ports:
Ring-In
Pin
1 RX– (Main Ring)
2 Ground
3 Ground
4 Ground
Pin
5 TX– (Backup Ring)
7 Ground
6 RX+ (Main Ring)
8 Ground
9 TX+ (Backup Ring)
Ring-Out 1 TX– (Main Ring)
2 Ground
3 Ground
4 Ground
5 RX– (Backup Ring)
7 Ground
6 TX+ (Main Ring)
8 Ground
9 RX+ (Backup Ring)
RING- IN
FEMALE DB-9 RECEPTACLE
(Main Ring) RX-
1
2
Common
Ground
(Backup Ring) TX5
3
4
6
RX+ (Main Ring)
7 Common
Ground
8
9
TX+ (Backup Ring)
RING-OUT
FEMALE DB-9 RECEPTACLE
(Main Ring) TX1
2
Common
Ground
(Backup Ring) RX5
3
4
Figure 2-2. Trunk Cable Connections
6 TX+ (Main Ring)
7
Common
Ground
8
9 RX+ (Backup Ring)
Page 2-6
REQUIREMENTS/SPECIFICATIONS
2.2.3 Ring Sequence
The ring sequence on the TRMIM-10R begins at the Ring-In, goes out to the Flexible Network Bus (FNB) then, after threading through other attached token ring boards, returns from the FNB to sequence through the TCU ports (in port number order) and finally out the
Ring-Out port. The following example serves to illustrate the ring sequence in an MMAC with multiple token ring boards:
Example: TRMIM-22P in slot 1 with ports 2, 5, 8, & 12 in use.
TRMIM-10R in slot 2 with ports 1, 2, 3, 5, and 6 in use.
TRMIM-12 in slot 3 with ports 1, 5, 7, 11, & 12 in use.
All three boards are attached via the FNB.
The ring sequence in this example is from Slot 2, Ring-In port via the
FNB to Slot 3, ports 1, 5, 7, 11, 12, via the FNB to Slot 1 ports 2, 5, 8,
12; then, returning to the TRMIM-10R in Slot 2 threading through ports 1, 2, 3, 5, and 6, then out the Ring-Out port.
2.2.4 LANVIEW LEDs
There are a number LANVIEW LEDs on the front panel of the
TRMIM-10R. The exact locations for these LEDs are illustrated in
Figure 2-3. Table 2-6 describes the functions for each LED.
Label Color
Table 2-6. LANVIEW LEDs
Description
16 Mb Yellow Ring Speed Indicator
ON TRMIM-10R is set for 16 Mbit/sec
OFF TRMIM-10R is set for 4 Mbit/sec
RI/RO Green Ring-In/Ring-Out Status (2)
Status ON Respective ring port is in a non-wrap state
OFF Respective ring port is in a wrap state
ERR Red ON TRMIM-10R hardware error detected
OFF Normal operation
Link Green Link Attached (10 - One LED for each TCU port)
Attached ON The respective port is inserted into the ring.
OFF The respective port is removed (bypassed) from the ring.
Page 2-7
REQUIREMENTS/SPECIFICATIONS
SN
TRMIM-10R
16Mb ERR
16Mb (Yellow) LED
ERR (Red) LED
7 1
LINK ATTACHED (Green) LED
(one for each trunk coupling port)
RI 5
RING-IN/RING-OUT PORT STATUS (Green) LED
RO 6
TOKEN RING
Figure 2-3. TRMIM-10R LANVIEW LEDs
SAFETY
WARNING: It is the responsibility of the person who sells the system to which the TRMIM-10R will be a part to ensure that the total system meets allowed limits of conducted and radiated emissions.
This equipment is designed in accordance with UL478, UL910,
NEC 725-2(b), CSA, IEC, TUV, VDE Class A, and meets FCC part 15, Class A limits.
Page 2-8
REQUIREMENTS/SPECIFICATIONS
SERVICE
MTBF (MHBK-217E):
MTTR:
>119,951 hrs.
<0.5 hr.
PHYSICAL
Dimensions:
Weight:
13.4D x 11.5H x 2.0W inches
(34.0D x 29.2H x 5.1W centimeters)
(includes front panel)
2 lbs. 2 oz.
(963.9 grams)
Page 2-9
INSTALLING THE TRMIM-10R
CHAPTER 3
INSTALLING THE TRMIM-10R
This chapter contains instructions for configuring and installing the
TRMIM-10R into a MMAC and includes instructions for connecting station and trunk cabling. Check that all requirements listed in
Chapter 2, Installation Requirements/Specifications, are met before installing the MIM.
3.1 UNPACKING THE TRMIM-10R
Prior to installation, unpack and visually inspect the TRMIM-10R for damage:
1.
Carefully remove the TRMIM-10R from the shipping box. Save the box and materials in the event that the unit has to be repackaged and shipped.
CAUTION: Electro-Static Discharges (ESD) will damage the
TRMIM-10R. Observe all precautions to prevent electrostatic discharges and when handling the TRMIM-10R, hold only the edges of the board or the metal front panel. Avoid touching the components or surface of the TRMIM-10R.
2.
Remove the TRMIM-10R from its protective plastic bag and set it on top of its protective bag in a static free area.
3.
Inspect the MIM for physical damage and contact Cabletron
Systems' Technical Support immediately if any problems exist.
3.2 INSTALLING THE TRMIM-10R INTO THE MMAC
The TRMIM-10R is designed to be easily installed into an MMAC product. When you install the TRMIM-10R, the following guidelines must be followed:
• Slot 0 of the MMAC is a reserved slot. The TRMIM-10R cannot be installed into Slot 0.
Page 3-1
INSTALLING THE TRMIM-10R
• If the TRMIM-10R is being installed into an MMAC-8, or MMAC-
8FNB, be sure that a Power Supply Module (PSM or PSM-R) is installed in the associated rear power supply slot. The PSM or
PSM-R is the source of power for MMAC modules. One PSM or
PSM-R is required for every two MIMs.
NOTE: The PSM-R is a Redundant Power Supply Module, that is recommended for use with the MMAC-8FNB (equipped with a
Flexible Network Bus).
• To link several Cabletron Systems' Token Ring products that are installed in the same MMAC, the MMAC must be configured with a backplane and the boards must be set to the same ring speed and in consecutive slots.
Install the TRMIM-10R as follows:
1.
Position the hardware jumper on the proper pins on the TRMIM-
10R to select either 4 or 16 Mbit/sec as the default ring speed (see
Figure 3-1). The speed setting affects the number of stations and the maximum lobe length. Refer to Chapter 2, Installation
Requirements/Specifications for additional information.
NOTE: The network speed is also selectable by software. The software selection overrides the hardware jumper selection.
2.
Power the MMAC chassis off, if it is not already powered off, by unplugging the AC power cord from the wall outlet.
3.
Remove the selected blank panel from the MMAC and slide the
TRMIM-10R (see Figure 3-2) into the MMAC card cage. Be sure that the board is in the guides at the top and bottom of the card cage.
4.
Secure the module to the MMAC by tightening the knurled knobs.
Failure to firmly secure the MIM may result in improper operation.
5.
Power the MMAC chassis on.
Page 3-2
INSTALLING THE TRMIM-10R
Twelve DB-9 Connectors
(Six on mother board, and six on daughter board)
4 Mbit/sec
16 Mbit/sec
Network Speed Jumper
J1
J1
Mother board Daughter board
Front
Panel
Figure 3-1. Network Speed Jumper
MMAC-8
TRMIM-10R
KNURLED KNOBS
IRM
TRMIM-10R
BOARD SLOT
TOKEN RING
Figure 3-2. Installing the TRMIM-10R
Page 3-3
INSTALLING THE TRMIM-10R
3.3 ATTACHING CABLES TO THE TRMIM-10R
Prior to connecting cables, check that the pinout and maximum cable lengths throughout the system conform to the requirements described in Chapter 2, Installation Requirements/Specifications.
The trunk coupling unit (TCU) and Ring-In/Ring-Out trunk ports of the TRMIM-10R are not sensitive to signal polarity. If the (+) and (-) lines within a pair are reversed, the network will still function properly due to the differential Manchester encoding. Operating in this condition is not recommended. When discovered, the cable connections should be corrected according to the information provided in Chapter 2, Installation Requirements/Specifications.
3.3.1 Connecting Lobe Cabling
The physical lobe cable (see Figure 3-3) between the TRMIM-10R and a token ring station consists of two pairs of wire: a transmit signal pair (TX+, TX-) and a receive signal pair (RX+, RX-). The transmit pair from the TRMIM-10R connects to the receive pair of the station and the receive pair from the TRMIM-10R connects to the transmit pair of the station. For example, TX+ from the TRMIM-10R connects to RX+ of the station and RX+ from the TRMIM-10R connects to TX+ on the station. This provides the necessary Crossover or Null Modem
Effect.
Trunk Coupling Port
Lobe Cable
RED TX+
TX–
6
1
GREEN
RX+ 9
RX–
5
ORANGE
BLACK
Token Ring Station
6 RX+
1 RX–
9 TX+
5 TX–
DB-9 Connectors
Figure 3-3. STP Connections
Page 3-4
INSTALLING THE TRMIM-10R
Attaching STP Lobe Cables to the TRMIM-10R
1.
Connect the male DB-9 connector from one end of the STP lobe or patch panel cable to the desired TCU port on the TRMIM-10R .
2.
If a patch panel is being used, connect the other end of the cable to the appropriate patch panel jack. (Install DB-9 to MIC adapters as needed.)
3.
Repeat this process for each station.
Attaching the STP Lobe Cable at the Station
Cabling at the Token Ring station may require adapter patch cables to permit mating between the wall plate and the station. Select the appropriate patch cable: DB-9 at both ends, or DB-9 to Medium
Interface Connector (MIC) (illustrated in Figure 3-4). If an adapter is used, attach the adapter to the cable before connecting the twisted pair cable to the station. Connect the wall plate end of the cable to the wall plate. Connect the other end of the cable to the port on the token ring station.
3.3.2 Connecting Trunk Cables
The TRMIM-10R Ring-In/Ring-Out ports support STP trunk cable connections. Connect the STP trunk cables to the TRMIM-10R as follows:
1.
Attach the male DB-9 connector at one end of the STP trunk cable to its respective Ring-In or Ring-Out port.
NOTE: When only one TRMIM-10R is installed, forming an independent ring network, wrap jumpers must be installed at the
Ring-In and Ring-Out ports of the TRMIM-10R.
Page 3-5
INSTALLING THE TRMIM-10R
2.
If a patch panel is being used, connect Ring-In from the patch panel to Ring-In on the TRMIM-10R and Ring-Out from the patch panel to Ring-Out on the TRMIM-10R. If connecting directly to another concentrator, daisy-chain the connections, Ring-In to
Ring-Out, from concentrator to concentrator. For some installations, DB-9 to MIC adapters may be needed.
3.4
FINISHING THE INSTALLATION
Complete the installation as follows:
1.
Be sure the MMAC and the stations are powered on.
2.
Check that the LEDs on the MIM and any LEDs on the stations are indicating normal operation (TRMIM-10R red Error LED off and no error indications at the stations). If you encounter errors or abnormal operation, proceed to Chapter 4, Testing and
Troubleshooting.
The green Link Attached LEDs on the MIM should be illuminated for each station that is inserted into the ring. The yellow 16Mb
LED should only be on if 16 Mbit/sec ring speed is desired.
3.
Configure the networking software.
The TRMIM-10R is now ready for operation. Before placing the network into service, test the installation thoroughly, making sure that all stations are able to be addressed and that the data is being relayed without error. Ensure that the networking software is configured properly to match the installed network.
Page 3-6
TESTING AND TROUBLESHOOTING
CHAPTER 4
TESTING AND TROUBLESHOOTING
This section contains procedures to verify the cabling connecting the
TRMIM-10R to the token ring network and any attached stations. A description of LANVIEW and its function in troubleshooting physical layer network problems is also provided.
4.1 INSTALLATION CHECK-OUT
Perform the following steps to check-out the installation of the
TRMIM-10R:
1.
Be sure that the token ring stations and the MMAC match the
AC power source (120 Vac or 240 Vac) and are powered on.
2.
Trace the ring path through the network, to be sure that there are no breaks in the ring and that it is free from logical design errors. While tracing the ring: a.
Check each cable connection on the MIM.
b.
Verify that the pinout for every connector is correct.
c.
Check the cable conductors for continuity. Cable testers are available for this task.
d.
Check each cable connection at patch panels and wall plates.
3.
Check the network ring speed: a.
Check that the ring speed matches the station and cable specifications mentioned in Chapter 2, Installation Re-
quirements/Specifications.
b.
Verify all devices on the ring network are set to the same ring speed. Check all MIMs and stations in the network.
4.
Verify that the maximum number of stations and maximum cable lengths for each station are not exceeded.
Page 4-1
TESTING AND TROUBLESHOOTING
When these checks have been successfully completed for each connection to the TRMIM-10R, the MIM is ready for normal operation. If further problems occur, contact Cabletron Systems' Technical Support.
4.2 USING LANVIEW
LANVIEW is Cabletron Systems' built-in visual diagnostic and status monitoring system. Using LANVIEW, your network troubleshooting personnel can quickly scan the LANVIEW LEDs to observe network status or diagnose network problems, and determine which node or segment is faulty. The definitions and locations for the front panel
LANVIEW LEDs are illustrated in Figure 4-1.
SN
TRMIM-10R
16Mb ERR
16Mb (Yellow) LED
ON - Ring speed set for 16 Mbit/sec
OFF - Ring speed set for 4 Mbit/sec
7 1
ERR (Red) LED
ON - Hardware error detected in
TRMIM-10R
OFF - Normal operation
LINK ATTACHED (10 - Green) LED
(one for each trunk coupling port)
ON - Respective station is inserted into
the ring.
OFF - Respective station is removed
(bypassed) from the ring.
RI 5
RING-IN/RING-OUT PORT STATUS (2 - Green) LED
(one for each ring connection)
ON - Respective Ring-In/Ring-Out port is in a
non-wrap state
OFF - Respective Ring-In/Ring-Out port is in a
wrap state
RO 6
TOKEN RING
Page 4-2
Figure 4-1. TRMIM-10R LANVIEW LEDs
TESTING AND TROUBLESHOOTING
• 16 Mb - The Ring Speed LED (Yellow) is lit to indicate that the
TRMIM-10R ring speed is set to 16 Mbit/sec. When this indicator is not lit, the ring speed is set to 4 Mbit/sec. The ring speed is set to a default setting by hardware jumper, J1 (refer to Chapter 3,
Installing the TRMIM-10R, for setting this jumper). The
TRMIM-10R is set to the default ring speed at power on. The ring speed can be changed via local network management software.
• RI/RO Status - The ring status indicators (2, Green) indicate the state of the Ring-In and Ring-Out ports. The normal condition is lit, indicating that the respective ring port is in a non-wrap state.
When either indicator is not lit, it indicates that the respective ring port has been set to the wrap state by network management software. (The TRMIM-10R does not automatically wrap to recover from ring segment failure.)
• ERR - The error indicator (Red) should not be lit under normal operating conditions. When lit this LED indicates the detection of a TRMIM-10R hardware failure. If the problem persists, contact
Cabletron Systems' Technical Support.
• Link Attached - Ten Link Attached LEDs (Green), one for each
TCU port indicate that the station attached to the respective TCU port is powered on and inserted into the ring. When a link attached LED is not lit, the respective port is inactive, and the station is removed (bypassed) from the ring.
Page 4-3
BASIC TOKEN RING NETWORKS
APPENDIX A
BASIC TOKEN RING NETWORKS
This Appendix covers the basic operation and concepts related to design considerations for token ring networks.
A.1 BASIC TOKEN RING OPERATION
A token ring network is made up of a number of stations electrically connected to form a continuous loop. Physically, the stations are usually arranged in a star pattern around a hub or concentrator module. The hub or concentrator provides ring access for several stations that are electrically (or optically in the case of fiber optic media) attached to the ring. The connections at the hub form wiring drops, called lobes, that extend out to each of the attached stations and return to the hub (see Figure A-1).
STATION 3
STATION 2
STATION 4
STATION 1
HUB STATION 5
STATION 8
STATION 6
STATION 7
Figure A-1. Typical Token Ring Physical Installation
Page A-1
BASIC TOKEN RING NETWORKS
Basic Token Ring Protocol
This summary briefly covers a basic subset of the overall token ring access protocol. The IEEE Standard 802.5 provides greater detail on token ring access methods and should be referenced whenever more complete information is needed.
Each station attached to the ring is identified by a unique station address differentiating it from all other stations. When a token ring station is activated and inserted into a ring, several actions are initiated to maintain order on the ring. All the active stations enter into a monitor contention dialogue, resulting in one station (the highest currently active address) establishing itself as the Active
Monitor (AM). As part of its duties, the AM initializes the ring and transmits a special message frame called a token.
The token circulates around the ring from station to station. Receipt of the token grants a station the privilege of accessing the ring to transmit data. When a station receives a token and uses the opportunity to transmit information, it appears that the token is removed from the ring and held by the station for the duration of the transmission. In reality, the token is modified by the station and used to create the data frame. The token is divided and the information is inserted between the modified Access Control (AC) field, and the Ending Delimiter (ED). Figure A-2 shows the token and information frame formats. Each station receives the token from a station preceding it on the ring and either uses it while transmitting data or passes (transmits) it to the next active station on the ring. When a station has data to transmit, the station modifies the token AC field, inserts its data into the frame between the AC and ED, waits for the transmission to circulate completely around the ring, strips its own data transmission from the ring, and then restores the token. A Token Holding Timer (THT) controls the length of time that any station may retain the token. Here is a typical token ring sequence:
1.
AM initiates the ring and places the token on the ring.
2.
Station xxx wants to send some data to station yyy. Station xxx modifies the token by inserting the information addressed to station yyy.
Page A-2
BASIC TOKEN RING NETWORKS
3.
The frame addressed for yyy circulates around the ring. All stations in the ring examine the frame, checking the address, in successive order. When the transmission gets to yyy, station yyy copies the data as it goes past.
4.
When the original transmission finishes the trip around the ring and is seen by station xxx again, station xxx removes the transmission from the ring. At this time, if station xxx has no more data to send or if its Token Holding Time (THT) has expired, station xxx releases the token back onto the ring.
5.
The ring is now available for use by another station. The token resumes its circulation until it reaches the next station that is waiting to send data. Here, the process will begin again with that station seizing the token.
Unless an error occurs that disrupts normal token passing, the original token remains in circulation. Lost tokens are detected by the
AM and appropriate corrective procedures are initiated.
TOKEN FRAME
SD AC ED
SD - Starting Delimiter (1 octet)
AC - Access Control (1 octet)
FC - Frame Control (1 octet)
DA - Destination Address (2 or 6 octets)
SA - Source Address (2 or 6 octets)
INFO - Information (0 or more octets)
FCS - Frame Check Sequence (4 octets)
ED - Ending Delimiter (1 octet)
FS - Frame Status (1 octet)
INFORMATION FRAME
SD AC FC DA SA INFO FCS ED FS
Figure A-2. Token Ring Frame Formats
Page A-3
BASIC TOKEN RING NETWORKS
Early Token Release
Early Token Release (ETR) is a second protocol option presented in the IEEE 802.5 Standard. ETR is an optional protocol that may be used with 16 Mbit/sec 802.5 token ring networks. It has the advantage of increasing the efficiency of the ring by allowing transmissions from more than one station to occupy the ring at the same time. This protocol is similar to the basic token ring protocol in that possession of the token determines the transmitting station, but with ETR the token is returned to the ring immediately following the message frame or upon THT expiration. ETR is a function of the network software and, when used, is usually invoked dynamically in response to increased network loads.
Expanding the Token Ring
Concentrators, repeaters, converters and bridges are found throughout token ring networks. They are used to create ring topologies to meet the specific needs of many different network applications. Some of these topologies are discussed in Appendix B.
Together with Figure A-3, the following descriptions provide a brief introduction to these components. The network functions provided by the following devices are often combined in a single device.
A concentrator is a device that provides multiple trunk coupling unit ports, bounded by externally accessible Ring-In and Ring-Out trunk ports. The primary function of a concentrator is to serve as a hub, providing trunk coupling units for attaching stations and controlling access to the ring. Each trunk coupling unit port can be electrically shorted to bypass the attached lobe when a station is disabled or when the lobe cable is disconnected. A concentrator is referred to as an Active Concentrator when the Ring-In/Ring-Out trunk ports provide regeneration and retiming of ring signals.
Passive Concentrators rely on the drive from the transmitting station to carry a message to its destination. Multiple concentrators are often linked via their trunk connections to form a single larger ring.
Repeaters are used when the length of the the main ring must be extended beyond the drive distance of other components on the ring.
The repeater’s primary role is to regenerate and retime the signals on the ring. They are often used to connect concentrators together to form a larger ring. Active concentrators provide the same regeneration and retiming function as a repeater and some, as in the
Page A-4
BASIC TOKEN RING NETWORKS case of Cabletron Systems' Token Ring Repeater (TRRMIM-16), convert from one media type to another (eg. shielded twisted pair to fiber optic).
Converters (not illustrated) provide the means for changing from one media type to another. Usually, the conversion allows a particular ring segment to cover a greater distance. Converters typically regenerate and retime signals as part of their functions.
Bridge devices (not illustrated) connect rings that cannot be expanded (at their maximum number of stations) or rings that are operating at different speeds (4 Mbit/sec vs. 16 Mbit/sec). They do not expand a single network, rather they connect multiple networks together. They maintain routing information, filter messages that cross the bridge, regenerate signals and provide buffering required for network synchronization.
MMAC
Chassis
TRMIM-10R
Concentrator #1
Ring-In Ring-Out
TRC-800
Concentrator #2
Ring-In Ring-Out
MAIN RING
Ring-Out
MMAC
Chassis TRRMIM-16
Repeater
TRMIM-12
Ring-In
Figure A-3. Repeaters In a Token Ring
Page A-5
BASIC TOKEN RING NETWORKS
Reliability
Since token ring networks depend on ring topology for proper operation, the entire network is vulnerable to the frailties of each ring segment. Arranging the ring as a star, using concentrators, and providing trunk coupling units for the station connections reduce the risk of a single failing node bringing the entire network down. To further reduce this vulnerability, a redundant data path is provided in the main ring trunk cabling.
While our theoretical ring required media capable of only one-way traffic to achieve the circular flow of data, actual token ring applications use media that provides two ring paths, a primary ring and a backup ring. This backup ring is used to restore the continuity of the ring in the event of a failed trunk segment (broken trunk cable). Figure A-4 illustrates how the open ends of the ring can be
wrapped into the backup ring, restoring continuity through the creation of a new ring. (Some devices will wrap automatically when a problem is detected. Others require human intervention to restore the ring.) The ability to wrap and bypass trunk segments introduces other problems. The recovery process produces a much longer physical trunk cable length. When this length exceeds the maximum drive distance, the problem must be solved by the network designer by adjusting cable lengths or installing repeaters in the ring.
RING-IN
CONCENTRATOR #2
WRAP
RING-OUT RING-IN
CONCENTRATOR #3
RING-OUT
PRIMARY RING
BACKUP RING
RING-OUT
CONCENTRATOR #1
RING-IN
Figure A-4. Wrapping a Broken Ring
Page A-6
BASIC TOKEN RING NETWORKS
A.2 DESIGN CONSIDERATIONS
A major design consideration is ring length. The ring propagation must be long enough to accommodate an entire token (24 bit times) and still be short enough for the transmitting devices to reliably send information to the next station. The AM inserts an artificial delay that prevents the ring from appearing too short. Overly long ring lengths create a problem as well, but these problems are best solved through restraints in the network design.
Drive Distance is the limit of reliable signal propagation around the ring. The cable length between a sending and receiving station must not exceed the drive distance. The cable lengths that make up the drive distance include the lobe from the sending station to the concentrator, the sum of the trunk cable segments around the ring and, since the sending station must ultimately remove the original message from the ring, the lobe from the concentrator to the sending station. Figure A-5 illustrates the cables that make up the drive distance in a token ring.
50
METERS
CONCENTRATOR #3
CONCENTRATOR #2
150
METERS
75
METERS
CONCENTRATOR #1
DRIVE DISTANCE
LOBE CABLING
TRUNK CABLING
LONGEST LOBE
(150 METERS)
Figure A-5. Cable Lengths in a Token Ring
When a wrap occurs that bypasses the shortest segment of trunk cable on the ring, it produces a “worst case” ring length referred to as the Adjusted Ring Length (ARL). Since the lobe is easily bypassed by the concentrator’s trunk coupling units, lobe cabling does not provide a backup path. Consequently, a wrap affects only the main ring (trunk cables). The lobe cable length is not included in the ARL.
Page A-7
BASIC TOKEN RING NETWORKS
ARL is calculated by combining the lengths of all the trunk cables, subtracting the length of the shortest trunk cable (typically an 8-foot patch cable within a wiring closet) and then doubling the result (Lobe cabling is not part of the ARL calculation). The impact of ARL on drive distance is apparent when we examine the resulting calculation for drive distance. The ARL plus the Longest Lobe Length is now the maximum drive length. This maximum drive length is the limit of reliable data transmission. (Appendix C provides procedures and tables to assist in calculating cable lengths, giving consideration to
ARL.
Figure A-6 shows the impact of a broken trunk segment on overall ring length. Without the break, the ring length is 275 meters and the drive distance for the station at the longest lobe is 575 meters (275 +
(2 x 150)). With the 50-meter section of trunk cable between
Concentrator #2 Ring-Out and Concentrator #3 Ring-In broken, the two ring ports must be wrapped, connecting the primary ring to the backup ring, and bypassing the broken trunk cable. In this condition, the ring length increases from 275 meters to 450 meters (2 x (75 +
150)) and the drive distance becomes 750 meters.
RING-OUT
50
METERS RING-IN
CONCENTRATOR #3
CONCENTRATOR #2
WRAP
PRIMARY RING
BACKUP RING
150
METERS
75
METERS
CONCENTRATOR #1
Figure A-6. Adjusted Ring Length
LONGEST LOBE
(150 METERS)
Page A-8
APPLICATIONS
APPENDIX B
APPLICATIONS
This Appendix presents the following network applications as examples of how the TRMIM-10R may be used in a token ring network.
These are examples to help clarify features of the TRMIM-10R and applications are NOT limited to those shown here.
• Adding to an existing Token Ring Network
• Separate Token Ring Networks in One MMAC
• Token Ring Networks Bridged Together
• MMAC with Ethernet and Token Ring Operating Simultaneously
B.1 ADDING TO AN EXISTING TOKEN RING NETWORK
Figure B-1 shows the addition of an MMAC with a TRMIM-12 and a
TRRMIM-16 into an existing token ring network. Here, the
TRRMIM-16 is used to insert an MMAC and its token ring products into the ring. Any concentrator (with externally accessible trunk ports) designed for use in an MMAC can be used. The Ring-In and
Ring-Out ports of the TRRMIM-16 are connected to Ring-In and Ring-
Out ports of the adjacent concentrators. The existing token ring network could consist of many vendors' products.
Ring-In
Concentrator #1 Concentrator #2
Ring-Out / Ring-In
Ring-Out
MMAC
Chassis
Ring-Out
TRRMIM-16
Repeater
TRMIM-12
Ring-In
Token Ring Network with two concentrators and one MMAC with TRRMIM-16 and TRMIM-12.
Figure B-1. Installing into an Existing Ring Network
Page B-1
APPLICATIONS
B.2 SEPARATE TOKEN RING NETWORKS IN ONE MMAC
Figure B-2 shows three independent Token Ring Networks within the same MMAC-8. The MMAC-8 has eight slots. The IRM occupies slot
0, leaving seven slots available for network boards. Cabletron
Systems' token ring products are recognized on the MMAC-8FNB
Flexible Network Bus (FNB) backplane by a unique identifier. If an
FNB is installed, when the MMAC is powered on, all the adjacent token ring MIMs set to the same ring speed will be automatically linked together forming a single larger ring network. If several independent ring networks are desired, the configuration must be set, via the local (IRM) management console, so as to isolate specific
MIMs. MIMs set to different ring speeds (e.g. one at 4 Mbit/sec and one at 16 Mbit/sec) cannot be linked together.
Example:
MMAC-8FNB, one TRMIM-10R, one TRMIM-22P, five TRMIM-12s and one IRM.
Slot 0 IRM
Slot 1 TRMIM-10R for ring network #1 at 4 Mbit/sec
Slot 2 TRMIM-22P for ring network #1 at 4 Mbit/sec
Slot 3 first TRMIM-12 for ring network #2 at 4 Mbit/sec
Slot 4 second TRMIM-12 for ring network #2 at 4 Mbit/sec
Slot 5 first TRMIM-12 for ring network #3 at 16 Mbit/sec
Slot 6 second TRMIM-12 for ring network #3 at 16 Mbit/sec
Slot 7 third TRMIM-12 for ring network #3 at 16 Mbit/sec
MMAC-8FNB
Token Ring Network #1 made up of a
TRMIM-10R and one TRMIM-22P running at 4 Mbit/sec.
Token Ring Network #2 made up of two TRMIM-12s at 4 Mbit/sec.
Token Ring Network #3 made up of three TRMIM-12s at 16 Mbit/sec.
NOTE:
Management software can be used to control the ring speed and linking of
Token Ring Network Boards.
Figure B-2. Several Independent Ring Networks
Page B-2
APPLICATIONS in One MMAC-8FNB
B.3 TOKEN RING NETWORKS BRIDGED TOGETHER
Figure B-3 illustrates the bridging of two token ring networks together using a token ring to token ring network bridge. Bridging ring networks is necessary when: the networks are of different ring speeds (one at 4 Mbit/sec and the other at 16 Mbit/sec), or when there is a need for networks to be connected and one or both of the rings is at maximum capacity. In Figure B-3, one network is running at
4 Mbit/sec and the other is running at 16 Mbit/sec. The 16 Mbit/sec ring network with 130 stations is close to its maximum capacity of
136 stations. When the two networks are connected, the bridge is
Token Ring Network running at 4 Mbit/s
249 stations maximum plus the bridging device
TOKEN RING
TO
TOKEN RING
BRIDGE
Token Ring Network running at 16 Mbit/s
135 stations maximum plus the bridging device counted as a station in both rings.
Figure B-3. Using a Bridge to Connect Ring Networks
B.4 MMAC WITH ETHERNET AND TOKEN RING
SIMULTANEOUSLY
Figure B-4 illustrates the simultaneous installation of an Ethernet network with a token ring network in the same MMAC. To connect the two networks together requires a token ring to Ethernet bridge.
Without this bridge, information cannot pass between the two networks. In this illustration the Ethernet and token ring networks are
Page B-3
APPLICATIONS not able to communicate with each other.
Ethernet Network
T
MMAC-8FNB with IRM,
THN-MIM, and
TRMIM-12.
T
AUI Cable
Since the Ethernet and Token Ring
Networks are NOT
Bridged together by a bridging device, they can NOT share data.
Token Ring Network
T
Figure B-4. Token Ring and Ethernet in the Same MMAC
Page B-4
CALCULATING RING LENGTH
APPENDIX C
CALCULATING RING LENGTH
This Appendix presents methods for calculating cable lengths for
passive token ring networks or passive network segments giving consideration to adjusted ring length (ARL). These calculations differ between networks that are wholly contained within a single
wiring closet and networks spanning multiple wiring closets.
This appendix describes both network configurations. Be sure to use the tables and instructions that apply to your network’s wiring when calculating the cable lengths.
A subsection titled Formulas follows the cable length calculations.
These formulas are presented as a source of additional reference information. They show how the tables on the Cable Length
Worksheets were compiled and are NOT needed for calculating your cable lengths.
C.1 RULES FOR CALCULATING CABLE LENGTHS
Chapter 2, Requirements/Specifications lists information related to the maximum lobe length, maximum drive distance, and specifications for various cable types that can be used with your
Cabletron Systems’ token ring products. Refer to that chapter whenever you have a question about recommended cable types or cable lengths.
Several rules must be followed when using the tables and instructions for ARL. They define the cable types and cable lengths used for various segments of your token ring.
Rules:
• Internal closet wiring is Type 6 cable in the following lengths:
- 8 feet - Trunk coupling unit port to patch panel
- 8 feet - Patch panel to concentrator ring ports
- 8 feet - Concentrator to concentrator
- 30 feet - Rack to Rack.
Page C-1
CALCULATING RING LENGTH
• With the exception of the wall plate to station cable, all the remaining Lobe and Trunk cables are Type 1 or Type 2.
• Wherever Type 6 or Type 9 cable is used, the length must be converted to the equivalent Type 1 cable length as follows:
(Length of Type 6 or 9 cable) x 3/2 =
Equivalent Type 1 or 2 length
C.2 SINGLE WIRING CLOSET NETWORKS
In a single wiring closet application, all of the trunk cabling is contained inside the closet, and the cable length of interest is the
lobe length (the cabling between the concentrator’s TCU port and the most distant token ring station). Use the STP Cable Length
Worksheet, Single Wiring Closet form at the end of this section to calculate your longest lobe cable length. Choose the column that matches your ring speed and complete the worksheet as follows:
1. The Maximum Drive Limit, when considering ARL, is one-half the maximum drive distance (2525 feet at 4 Mbit/sec or 1138 feet at 16 Mbit/sec) or 1263 feet at 4 Mbit/sec or 569 feet at 16 Mbit/ sec for STP cable.
2. Refer to the table at the bottom of the worksheet to find the
Internal Trunk Length for your wiring closet configuration.
3. Subtract the Internal Trunk Length from the Maximum
Drive Limit to obtain the Maximum Allowable Lobe Length:
Maximum Type 1 Lobe Length (see note) =
Maximum Drive Limit – Internal Trunk Length
NOTE: This operation may yield a lobe length greater than the recommended maximum (Type 1) of 656 feet for 4 Mbit/sec or 328 feet for 16 Mbit/sec. Installing a lobe that exceeds the recommended maximum could restrict future expansion of the network.
Page C-2
CALCULATING RING LENGTH
4.
Determine your Actual Longest Lobe length, combine:
TCU Port to patch panel (8 feet x 3/2)
Wall plate to wiring closet
Station to wall plate (If type 6, x 3/2)
12 feet
+ x feet
+ x feet
Longest Lobe Length
5.
Compare the Maximum Type 1 Lobe Length, calculated in step 3, with your network's longest lobe, from Step 4. If your
Actual Longest Lobe exceeds the Maximum Type 1 Lobe
Length (negative result in step 5), you must adjust your lobe length or add active components (repeaters) to extend the available trunk cable length.
Use Figure C-1 and the STP Cable Length Worksheet for Single
Wiring Closets at the end of this section to follow the calculations in this example of a 4 Mbit/sec ring:
Single Wiring Closet
1.
Maximum Drive Limit
4 Mbit/sec
1. 1263 ft.
2.
Internal Trunk Length
(7 concentrators in 2 racks = 150')
3.
Maximum Type 1 Lobe Length
4.
Actual Longest Lobe (Station 2)
5.
(8' x 3/2) + 185' + (30 x 3/2) = 242'
Result
2. – 150 ft.
3. 1113 ft.
4. – 242 ft.
5. 871 ft.
The result is positive and no repeaters or cable adjustments are needed.
If you need further assistance with your network design, contact
Cabletron Systems' Technical Support.
Page C-3
CALCULATING RING LENGTH
STATION 1
WALL
PLATE
LOBE CABLING
TRUNK CABLING
8 foot patch cables (Type 6) used within racks
8' of
Type 6
140' of
TYPE 1
185' of
TYPE 1
8' 8'
8'
30'
30'
WALL
PLATE
30' of
Type 6
STATION 2
WIRING CLOSET
Figure C-1. Wiring in a Single Wiring Closet
Formulas
Two formulas were used to create the tables for the STP Cable
Length Worksheets. The first defines the cabling for a single wiring closet with only one rack and the second for multiple racks within the wiring closet. The difference between the two formulas accounts for cabling between racks within a wiring closet. The term Internal Trunk Length refers to trunk cabling length within the wiring closet, adjusted to give consideration to
ARL. The actual calculations used in the table are as follows:
Page C-4
CALCULATING RING LENGTH
Single Rack
Internal Trunk Length =
(Concentrator to Concentrator Patch Cables) where:
Concentrator to Concentrator Patch Cables =
12' x number of Concentrators (see note)
Note: A patch cable or wrap connectors must be installed when only one concentrator is configured.
Multiple Rack
Internal Trunk Length =
(Rack to Rack Patch Cables +
Concentrator to Concentrator Patch Cables) where:
Rack to Rack Patch Cables = 45' x number of Racks
Concentrator to Concentrator Patch Cables =
12' x (number of Concentrators - number of Racks)
NOTE: You are hereby authorized to copy the next page (STP Cable
Length Worksheet) in this appendix. Copy the worksheet for your planning needs, but remember to keep a blank copy for future network configuration changes.
Page C-5
CALCULATING RING LENGTH
STP CABLE LENGTH WORKSHEET
Single Wiring Closet
1. Maximum Drive Limit
(1263 feet for 4 Mbit/s or 569 feet for 16 Mbit/s) 1.
4 Mbit/sec
1263 ft.
2. Internal Trunk Length
(Value from Table below)
3. Maximum Type 1 Lobe Length
(1) – (2) = (3)
2.
–
3.
ft.
ft.
1.
16 Mbit/sec
569 ft.
2.
–
3.
ft.
ft.
4.
– ft.
4.
– ft.
4. Actual Longest Lobe
5. If you get a negative result, adjust
cable lengths or add active
components to the ring.
5.
5.
Number of
Concentrators 1
14
15
16
17
18
19
8
9
10
11
12
13
1
2
3
4
5
6
7
26
27
28
29
20
21
22
23
24
25
30
31
32
33
2
Number of Racks (Single Closet)
3 4 5 6 7 8 9 10
12
24 90
36 102 135
Values are Type 1
Equivalent in feet
48 114 147 180
60 126 159 192 225
72 138 171 204 237 270
84 150 183 216 249 282 315
96 162 195 228 261 294 327 360
108 174 207 240 273 306 339 372 405
120 186 219 252 285 318 351 384 417 450
132 198 231 264 297 330 363 396 429 462
144 210 243 276 309 342 375 408 441 474
222 255 288 321 354 387 420 453 486
234 267 300 333 366 399 432 465 498
246 279 312 345 378 411 444 477 510
258 291 324 357 390 423 456 489 522
270 303 336 369 402 435 468 501 534
282 315 348 381 414 447 480 513 546
294 327 360 393 426 459 492 525 558
306 339 372 405 438 471 504 537 570
318 351 384 417 450 483 516 549 582
330 363 396 429 462 495 528 561 594
342 375 408 441 474 507 540 573 606
354 387 420 453 486 519 552 585 618
399 432 465 498 531 564 597 630
411 444 477 510 543 576 609 642
423 456 489 522 555 588 621 654
435 468 501 534 567 600 633 666
447 480 513 546 579 612 645 678
459 492 525 558 591 624 657 690
471 504 537 570 603 636 669 702
483 516 549 582 615 648 681 714
495 528 561 594 627 660 693 726
Page C-6
CALCULATING RING LENGTH
STP CABLE LENGTH WORKSHEET
16 Mbit/sec Single Wiring Closet
1. Maximum Drive Limit
(1263 feet for 4 Mbit/s or 569 feet for 16 Mbit/s) 1.
4 Mbit/sec
1263 ft. 1.
569 ft.
2. Internal Trunk Length
(Value from Table below)
3. Maximum Type 1 Lobe Length
(1) – (2) = (3)
2.
–
3.
ft.
ft.
2.
–
3.
ft.
ft.
4. Actual Longest Lobe 4.
– ft.
4.
– ft.
5. If you get a negative result, adjust
cable lengths or add active
components to the ring.
5.
5.
Number of
Concentrators 1
14
15
16
17
18
19
8
9
10
11
12
13
1
2
3
4
5
6
7
26
27
28
29
20
21
22
23
24
25
30
31
32
33
2
Number of Racks (Single Closet)
3 4 5 6 7 8 9 10
12
24 90
36 102 135
Values are Type 1
Equivalent in feet
48 114 147 180
60 126 159 192 225
72 138 171 204 237 270
84 150 183 216 249 282 315
96 162 195 228 261 294 327 360
108 174 207 240 273 306 339 372 405
120 186 219 252 285 318 351 384 417 450
132 198 231 264 297 330 363 396 429 462
144 210 243 276 309 342 375 408 441 474
222 255 288 321 354 387 420 453 486
234 267 300 333 366 399 432 465 498
246 279 312 345 378 411 444 477 510
258 291 324 357 390 423 456 489 522
270 303 336 369 402 435 468 501 534
282 315 348 381 414 447 480 513 546
294 327 360 393 426 459 492 525 558
306 339 372 405 438 471 504 537 570
318 351 384 417 450 483 516 549 582
330 363 396 429 462 495 528 561 594
342 375 408 441 474 507 540 573 606
354 387 420 453 486 519 552 585 618
399 432 465 498 531 564 597 630
411 444 477 510 543 576 609 642
423 456 489 522 555 588 621 654
435 468 501 534 567 600 633 666
447 480 513 546 579 612 645 678
459 492 525 558 591 624 657 690
471 504 537 570 603 636 669 702
483 516 549 582 615 648 681 714
495 528 561 594 627 660 693 726
Page C-7
CALCULATING RING LENGTH
C.3 MULTIPLE WIRING CLOSET NETWORKS
In multiple wiring closet applications, both external trunk cable length and lobe cable length must be considered in the overall drive distance for a passive ring. Use the STP Cable Length Worksheet,
Multiple Wiring Closet form at the end of this section to determine the cable lengths that can be used in multiple wiring closet token ring applications. Choose the column that matches your ring speed and complete the worksheet as follows:
1.
Determine your Actual Longest Lobe length, combine:
TCU Port to patch panel (8 feet x 3/2)
Wall plate to wiring closet
Station to wall plate (If type 6, x 3/2)
12 feet
+ x feet
+ x feet
Longest Lobe Length
2.
Refer to the table at the bottom of the worksheet to find the
Internal Trunk Length for each Wiring Closet (WC) in the multiple closet configuration. Add these values to find the total
Combined Trunk Length:
WC-1 + WC-2 + WC-n = Combined Trunk Length
3.
Add the Actual Longest Lobe (step 1) to the Combined Trunk
Length (step 2) to find the Internal Drive Distance and enter the sum here and on line 4a.
Internal Drive Distance =
Combined Trunk Length + Actual Longest Lobe
4.
The Maximum Drive Limit, when considering ARL, is one-half the maximum drive distance (2525 feet at 4 Mbit/sec or 1138 feet at 16 Mbit/sec) or 1263 feet at 4 Mbit/sec or 569 feet at 16 Mbit/ sec for STP cable.
5.
Subtract the Internal Drive Distance (step 3) from the
Maximum Drive Limit to obtain cable length available for the
External Trunk Cable Budget (outside the closets) in your configuration:
External Trunk Cable Budget =
Maximum Drive Limit - Internal Drive Distance
Page C-8
CALCULATING RING LENGTH
6.
Find the total length of the Actual Trunk Cable lengths between wiring closets.
7.
Compare the Actual Trunk Cable length with the External
Trunk Cable Budget (step 5). When your Actual Trunk
Cable length exceeds the External Trunk Cable Budget
(negative result in step 7), you must either adjust your lobe/ trunk lengths or add active components (repeaters) to extend the available trunk cable length.
Use Figure C-2 and the STP Cable Length Worksheet for Multiple
Wiring Closets to follow the calculation in this example of a 4 Mbit/ sec ring:
Multiple Wiring Closets 4 Mbit/sec
1.
Actual Longest Lobe (given as 55 feet) 1. 55 ft.
2.
Combined Trunk Length
117' + 165' + 213' = 495'
3.
Internal Drive Distance
4.
Maximum Drive Limit
4a. Internal Drive Distance
5.
External Trunk Cable Budget
2. + 495 ft.
3. 550 ft.
4. 1263 ft.
– 550 ft.
5. 713 ft.
6.
Actual External Trunk Cable Length
95' + 70' + 175' = 340'
7.
Result
6. – 340 ft.
7. 373 ft.
The result is positive and no repeaters or cable adjustments are needed.
If you need further assistance with your network design, contact
Cabletron Systems' Technical Support.
Page C-9
CALCULATING RING LENGTH
70'
WC-3
2 Racks
14 Concentrators
213 feet
WC-2
2 Racks
10 Concentrators
165 feet
95'
Token Ring Corporation
WC-1
2 Racks
6 Concentrators
117 feet
175'
55'
LONGEST
LOBE
Figure C-2. Building Cable Budget
Formulas
The formulas used to create the tables for the STP Cable Length
Worksheets yield values equal to the length of internal cabling within wiring closets (see Figure C-3) in a multiple closet configuration. The term Internal Trunk Length refers to trunk cabling length within the wiring closet, adjusted to give consideration to ARL. The actual calculation used in the table is described as follows:
Internal Trunk Length =
2 x (TCU Patch Cables) +
(Rack to Rack Patch Cables) +
(Concentrator to Concentrator Patch Cables)
Page C-10
CALCULATING RING LENGTH where:
TCU Patch Cables = 12'
Rack to Rack Patch Cables = 45' x (number of Racks - 1)
Concentrator to Concentrator Patch Cables =
12' x (number of Concentrators - number of Racks)
To Next
Wiring Closet
OUT
MAIN
RING
IN
From Previous
Wiring Closet
8'
STATION 1
TYPE 1 or 2
8'
WALL
PLATE
8'
8'
30'
TYPE 1 or 2
STATION 2
WALL
PLATE
LOBE CABLING
TRUNK CABLING
8 foot patch cables (Type 6) used within racks
WIRING CLOSET
Figure C-3. Wiring Closet Cabling
NOTE: You are hereby authorized to copy the next page (STP Cable
Length Worksheet) in this appendix. Copy the worksheet for your planning needs, but remember to keep a blank copy for future network configuration changes.
Page C-11
CALCULATING RING LENGTH
STP CABLE LENGTH WORKSHEET
Multiple Wiring Closets 4 Mbit/sec
1. Actual Longest STP Lobe 1.
ft.
2. Combined Trunk Length
(Sum of values for all closets, from Table below)
3. Internal Drive Distance
(1) + (2) = (3)
2.
+
3.
4. Maximum Drive Limit
(1263 feet for 4 Mbit/s or 569 feet for 16 Mbit/s)
4a. Internal Drive Distance (from 3)
4.
– ft.
ft.
1263 ft. ft.
1.
16 Mbit/sec ft.
2.
+
3.
4.
– ft.
ft.
569 ft. ft.
5. External Trunk Cable Budget 5.
ft.
5.
ft.
6. Actual External Trunk Cable Length 6.
– ft.
6.
– ft.
7. If you get a negative result, adjust
cable lengths or add active
components to the ring.
7.
ft.
7.
ft.
Number of
Concentrators 1
28
29
30
31
32
33
21
22
23
24
25
26
27
6
7
8
9
10
11
12
13
14
1
2
3
4
5
15
16
17
18
19
20
2
Number of Racks (Multiple Closets)
3 4 5 6 7 8 9 10
24
36
48
69
81 114
60 93 126 159
72 105 138 171 204
Values are Type 1
Equivalent in feet
84 117 150 183 216 249
96 129 162 195 228 261 294
108 141 174 207 240 273 306 339
120 153 186 219 252 285 318 351 384
132 165 198 231 264 297 330 363 396 429
144 177 210 243 276 309 342 375 408 441
156 189 222 255 288 321 354 387 420 453
201 234 267 300 333 366 399 432 465
213 246 279 312 345 378 411 444 477
225 258 291 324 357 390 423 456 489
237 270 303 336 369 402 435 468 501
249 282 315 348 381 414 447 480 513
261 294 327 360 393 426 459 492 525
273 306 339 372 405 438 471 504 537
285 318 351 384 417 450 483 516 549
297 330 363 396 429 462 495 528 561
309 342 375 408 441 474 507 540 573
321 354 387 420 453 486 519 552 585
333 366 399 432 465 498 531 564 597
378 411 444 477 510 543 576 609
390 423 456 489 522 555 588 621
402 435 468 501 534 567 600 633
414 447 480 513 546 579 612 645
426 459 492 525 558 591 624 657
438 471 504 537 570 603 636 669
450 483 516 549 582 615 648 681
462 495 528 561 594 627 660 693
474 507 540 573 606 639 672 705
Page C-12
CALCULATING RING LENGTH
STP CABLE LENGTH WORKSHEET
Multiple Wiring Closets 4 Mbit/sec
1. Actual Longest STP Lobe 1.
ft.
1.
16 Mbit/sec ft.
2. Combined Trunk Length
(Sum of values for all closets, from Table below)
3. Internal Drive Distance
(1) + (2) = (3)
2.
+
3.
4. Maximum Drive Limit
(1263 feet for 4 Mbit/s or 569 feet for 16 Mbit/s)
4a. Internal Drive Distance (from 3)
4.
– ft.
ft.
1263 ft. ft.
2.
+
3.
4.
– ft.
ft.
569 ft. ft.
5. External Trunk Cable Budget 5.
ft.
5.
ft.
6. Actual External Trunk Cable Length 6.
– ft.
6.
– ft.
7. If you get a negative result, adjust
cable lengths or add active
components to the ring.
7.
ft.
7.
ft.
Number of
Concentrators 1
19
20
21
22
23
24
25
13
14
15
16
17
18
1
2
3
4
5
6
7
8
9
10
11
12
26
27
28
29
30
31
32
33
2
Number of Racks (Multiple Closets)
3 4 5 6 7 8 9 10
24
36
48
69
81 114
60 93 126 159
72 105 138 171 204
Values are Type 1
Equivalent in feet
84 117 150 183 216 249
96 129 162 195 228 261 294
108 141 174 207 240 273 306 339
120 153 186 219 252 285 318 351 384
132 165 198 231 264 297 330 363 396 429
144 177 210 243 276 309 342 375 408 441
156 189 222 255 288 321 354 387 420 453
201 234 267 300 333 366 399 432 465
213 246 279 312 345 378 411 444 477
225 258 291 324 357 390 423 456 489
237 270 303 336 369 402 435 468 501
249 282 315 348 381 414 447 480 513
261 294 327 360 393 426 459 492 525
273 306 339 372 405 438 471 504 537
285 318 351 384 417 450 483 516 549
297 330 363 396 429 462 495 528 561
309 342 375 408 441 474 507 540 573
321 354 387 420 453 486 519 552 585
333 366 399 432 465 498 531 564 597
378 411 444 477 510 543 576 609
390 423 456 489 522 555 588 621
402 435 468 501 534 567 600 633
414 447 480 513 546 579 612 645
426 459 492 525 558 591 624 657
438 471 504 537 570 603 636 669
450 483 516 549 582 615 648 681
462 495 528 561 594 627 660 693
474 507 540 573 606 639 672 705
Page C-13
CALCULATING RING LENGTH
C.4 CALCULATING MIXED CABLE TYPES
Installations using mixed cable types must compensate for different cable attenuations. The maximum cable length for Type 6 and Type 9 cables is only 2/3 that of Type 1 cable. Use the following formulas to convert between Type 1/2 and Type 6/9:
Type 1/2 = 3/2 x Type 6/9
Type 6/9 = 2/3 x Type 1/2
The following problem and solution shows the calculations required for an installation using a combination of Type 1 and Type 6 cable:
The Problem
An installation with one wiring closet, containing twelve concentrators in three racks currently serves 120 stations. This exercise connects an additional station to an open TCU port on existing TRMIM-10R. The new station will require the longest lobe cable yet installed, 285 feet. From the table at the bottom of the Single Wiring Closet Cable Length Worksheet, we find the adjusted internal cable length for the wiring closet is 243 feet.
Assuming that an 8 foot Type 6 patch cable will be used between the wall plate and the new station, how much Type 1 cable is available to connect the local wall jack to the wiring closet patch panel?
Given:
— 8 foot (Type 6) patch cables will be used at the patch panel and wall plate
— 16 Mbit/sec ring speed and 120 stations.
— The internal wiring closet trunk length is 243 feet.
Page C-14
CALCULATING RING LENGTH
Solution
1.
Determine the Type 1 cable budget available for lobe cabling.
Drive Limit (Type 1, 16 Mbit/sec)
Type 1 cable length already expended
Type 1 budget for the longest lobe
569 feet
–243 feet
326 feet
2.
Find the Type 1 equivalent for the TCU to patch panel and wall jack to station
Type 6 patch cables.
Type 1 budget for the longest lobe 326 feet
Type 6 patch cable length (x 2) 16 feet
Conversion factor (Type 6 to Type 1) x 1.5
Type 1 budget for in-wall lobe cable
=>> – 24 feet
302 feet
Conclusion
The required lobe length (285') is less than the cable budget (326') and the required actual Type 1 cable for the lobe (285' – 16' =
269') is within the Type 1 budget for in-wall cabling (302'). The installation is feasible.
Page C-15
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