Cabletron Systems TRXI-22 User manual

TRXI-22, TRXI-24, TRXI-42, AND TRXI-44
TOKEN RING INTELLIGENT HUB
USER’S GUIDE
CABLETRON SYSTEMS, P. O. Box 5005, Rochester, NH 03867-0505

NOTICE
iii
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.
INNOEVENTSHALLCABLETRONSYSTEMSBELIABLEFORANYINCIDENTAL,
INDIRECT, SPECIAL, OR CONSEQUENTIAL DAMAGES WHATSOEVER
(INCLUDING BUT NOT LIMITED TO LOST PROFITS) ARISING OUT OF OR
RELATED TO THIS MANUAL OR THE INFORMATION CONTAINED IN IT, EVEN
IF CABLETRON SYSTEMS HAS BEEN ADVISED OF, KNOWN, OR SHOULD HAVE
KNOWN, THE POSSIBILITY OF SUCH DAMAGES.
© Copyright May 1994 by:
Cabletron Systems, Inc.
P.O. Box 5005, Rochester, NH 03867-0505
All Rights Reserved
Printed in the United States of America
Order Number: 9030740-02 May 94
TRXI-22 , TRXI-24 , TRXI-42 , TRXI-44, and TPIM are trademarks of Cabletron
Systems, Inc.
SPECTRUM, LANVIEW , and Remote LANVIEW are registered trademarks of
Cabletron Systems, Inc.
IBM is a registered trademark of International Business Machines Corporation.
DEC , VT200 , and VT300 are trademarks of Digital Equipment Corporation.
CompuServe is a trademark of Compuserve, Inc.
Printed On Recycled Pa
per

NOTICE
iv
FCC NOTICE
This device complies with Part 15 of the 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.
NOTE: This equipment has been tested and found to comply with the limits for a Class
A digital device, pursuant to Part 15 of the FCC rules. These limits are designed to
provide reasonable protection against harmful interference when the equipment is
operated in a commercial environment. This equipment uses, generates, and can radiate
radio frequency energy and if not installed in accordance with the operator’s manual,
may cause harmful interference to radio communications. Operation of this equipment
in a residential area is likely to cause interference in which case the user will be required
to correct the interference at his own expense.
WARNING: Changes or modifications made to this device which are not expressly
approved by the party responsible for compliance could void the user’s authority to
operate the equipment.
DOC NOTICE
This digital apparatus does not exceed the Class A limits for radio noise emissions from
digital apparatus set out in the Radio Interference Regulations of the Canadian
Department of Communications.
Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les
limites applicables aux appareils numériques de la class A prescrites dans le Règlement
sur le brouillage radioélectrique édicté par le ministère des Communications du Canada.
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NOTICE
v
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Industrial Way. Rochester, New Hampshire 03867

CONTENTS
vii
TABLE OF CONTENTS
CHAPTER 1 INTRODUCTION
1.1 USING THIS MANUAL............................................................1-1
1.2 GETTING HELP........................................................................1-2
1.3 TRXI OVERVIEW......................................................................1-2
1.4 TRXI FEATURES......................................................................1-3
1.5 REMOTE NETWORK MANAGEMENT CAPABILITIES ......1-5
1.6 RECOMMENDED READING...................................................1-5
CHAPTER 2 REQUIREMENTS/SPECIFICATIONS
2.1 CABLE SPECIFICATIONS.......................................................2-1
2.1.1 UTP Cable Specifications for the TRXI-22/24 Lobe Ports
and TPIM-T2.................................................................2-2
2.1.2 STP Cable Specifications For The TRXI-42/44 Lobe Ports
and TPIM-T1/T4............................................................2-4
2.1.3 Mixed Cable Types........................................................2-6
2.1.4 Multimode Fiber Optic Cable Specifications for the
TPIM-F2 ........................................................................2-7
2.1.5 Single Mode Fiber Optic Cable Specifications for the
TPIM-F3 ........................................................................2-8
2.2 CABLE RECOMMENDATIONS/TROUBLESHOOTING.......2-9
2.3 COM 1/COM 2 PORT SPECIFICATIONS..............................2-11
2.4 TPIM SPECIFICATIONS........................................................2-12
2.5 GENERAL SPECIFICATIONS...............................................2-17
CHAPTER 3 INSTALLATION
3.1 UNPACKING THE TRXI..........................................................3-1
3.2 ATTACHING THE STRAIN RELIEF BRACKET ...................3-1
3.3 INSTALLING THE TRXI..........................................................3-2
3.3.1 Rack Mounting the TRXI..............................................3-3
3.3.2 Wall Mounting the TRXI..............................................3-4
3.3.3 Free-Standing Installation...........................................3-5
3.4 SETTING THE RING SPEED SWITCH..................................3-6
3.5 SETTING THE NVRAM SWITCH ...........................................3-7
3.6 CONNECTING THE TRXI TO THE POWER SOURCE.........3-8
3.7 CONNECTING THE NETWORK LOBE PORT CABLING....3-8
3.8 INSTALLING THE TPIM RI/RO MODULES........................3-11

CONTENTS
viii
3.8.1 Setting the TPIM’s Phantom Switch and RI/RO Switch..
3-12
3.8.2 Installing a TPIM to the TRXI....................................3-13
3.8.3 Connecting a Twisted Pair Segment to the TPIM-T13-14
3.8.4 Connecting a Twisted Pair Segment to the TPIM-T2
or TPIM-T4 ..................................................................3-15
3.8.5 Connecting a Fiber Optic Link Segment to the TPIM-F2
or TPIM-F3 ..................................................................3-16
3.9 FINISHING THE INSTALLATION........................................3-18
CHAPTER 4 TESTING AND TROUBLESHOOTING
4.1 CHECKING THE INSTALLATION..........................................4-1
4.2 USING LANVIEW......................................................................4-2
4.3 THE LCD DISPLAY...................................................................4-3
4.3.1 Static System Messages................................................4-4
4.3.2 Alarm Messages.............................................................4-5
4.3.3 Unsaved Initialization Messages..................................4-6
4.3.4 Saved System Messages................................................4-7
CHAPTER 5 LOCAL MANAGEMENT
5.1 MANAGEMENT TERMINAL REQUIREMENTS...................5-2
5.1.1 Attaching the Management Terminal..........................5-2
5.1.2 Setting the Management Terminal Setup Parameters.5-
3
5.1.3 Modem Cable Configuration and Setup.......................5-4
5.2 ACCESSING LOCAL MANAGEMENT....................................5-5
5.3 USING LOCAL MANAGEMENT..............................................5-6
5.3.1 The System Level Screen..............................................5-8
5.3.2 The SNMP Community Names Screen......................5-13
5.3.3 The SNMP Traps Screen.............................................5-15
5.3.4 The Ring Security Screen............................................5-17
5.3.5 The Device Statistics Screen.......................................5-22
5.3.6 The Chassis Status View Screen................................5-28
5.3.7 The Component Status View Screen..........................5-30
5.3.8 The SNMP Tools Screen..............................................5-31

INTRODUCTION
Page 1-1
CHAPTER 1
INTRODUCTION
Welcome to the Cabletron Systems TRXI-22, TRXI-24, TRXI-42, and
TRXI-44 Token Ring Intelligent Hub User’s Guide .This manual
provides installation instructions, network requirements, and
reference information for the TRXI stand-alone concentrator. You
should have an understanding of Token Ring (IEEE 802.5) type data
communications networks and their physical layer components before
installing the TRXI.
Note : This manual uses the term TRXI to describe the TRXI -22, 24, 42,
and 44 unless otherwise specified.
1.1 USING THIS MANUAL
The following summary provides information about each chapter in
this manual. Read through the summary to familiarize yourself with
this manual’s organization and content.
Chapter 1,
Introduction , outlines the contents of this manual and
briefly describes features of the TRXI.
Chapter 2, Requirements/Specifications , describes cabling
requirements, network guidelines, and TRXI operating specifications.
Chapter 3, Installation , contains instructions for installing your
TRXI and connecting it to the network using the various media types.
This chapter includes instructions for setting the Ring Speed Switch,
setting the NVRAM Switch, installing the Token Ring Port Interface
Modules (TPIMs), and setting the TPIM Phantom Switch.
Chapter 4, Testing and Troubleshooting , contains procedures for
testing the TRXI after installation, a description of the LANVIEW®
LEDs, and explains the front panel LCD display.
Chapter 5, Local Management , describes how to access Local
Management. It also describes each of the Local Management screens
and the available commands.

INTRODUCTION
Page 1-2
1.2 GETTING HELP
If you need additional support related to the Cabletron Systems TRXI,
or if you have any questions,comments,or suggestions concerning this
manual, contact Cabletron Systems Technical Support:
By phone......................... [phone]
Monday-Friday; 8am - 8pm EST
By CompuServe
®
............ GO CTRON from any ! prompt
By Internet mail............. [email protected]
1.3 TRXI OVERVIEW
The TRXI stand-alone concentrator provides Trunk Coupling Units
(TCUs) for Shielded Twisted Pair (STP) or Unshielded Twisted Pair
(UTP) network lobe connections.The TRXI-22, 24, 42, and 44 are
functionally identical with the exception of the TCU lobe ports.
Cabletron offers the following TRXI configurations:
•
TRXI-22 ,twelve RJ45TCU lobe ports that support category 3,
4, and 5 UTP cabling.
• TRXI-24 , twenty-four RJ45 TCU lobe ports that support
category 3, 4, and 5 UTP cabling.
• TRXI-42 , twelve RJ45 TCU lobe ports that support IBM Type
1, 2, 6, or 9 STP cabling.
• TRXI-44 , twenty-four RJ45 TCU lobe ports that support IBM
Type 1, 2, 6, or 9 STP cabling.
Figure 1-1. The TRXI-24
DISPLAY
RI
RO
TRXI-24 TOKEN RING HUB WITH LANVIEW®
24 23 22 21 20 19 18 17 16 15 14 13
12 11 10 9 8 7 6 5 4 3 2 1
COM 2 COM 1
18 17 16 15 14 13
6 5 4 3 2 1
24 23 22 21 20 19
12 11 10 9 8 7 RO
RI
PWR
CPU ACT
MGMT16 Mb/s
RESET
DISPLAY

INTRODUCTION
Page 1-3
You can upgrade the TRXI-22 and TRXI-42 to twenty-four ports using
a twelve port upgrade kit available from Cabletron Systems
(Cabletron Part Number TRXI-24-UGKIT or TRXI-44-UGKIT).
The TRXI provides two additional ports for Ring In and Ring Out
connections.These ports support Cabletron’s Token Ring Port
Interface Modules (TPIMs).TPIMs provide full repeater functionality.
They are not included with the TRXI, but can be ordered separately
from Cabletron.Table 1-2 lists each TPIM.
1.4 TRXI FEATURES
Local Management
Local Management provides the tools to manage the TRXI and all of
its attached segments.You access Local Management by connecting a
Digital Equipment Corporation VT™ 320 series terminal or a PC
using VT320 emulation software to the TRXI’s COM 1 port.
LCD and Reset Button
The LCD provides status information about the TRXI such as power
up diagnostics, revision levels, serial numbers, and error alerts.The
TRXI also has a Reset Button to initialize the processor. Both the LCD
and the Reset Button are located on the front panel of the TRXI.
Ring Speed Switch
The Ring Speed Switch lets you select ring speeds of either 4 Mbps or
16 Mbps.The factory default setting is 16 Mbps.
LANVIEW LEDs
Cabletron Systems’ LANVIEW LED Status Monitoring and
Diagnostics System is a convenient troubleshooting tool that helps you
diagnose power failures, RI/RO status, cable faults, ring speed, link
problems, and network activity.
COM Port Applications
The front panel COM 1 port supports Local Management applications.
Future capabilities for TRXI’s serial ports include an SNMP proxy for
Uninterruptible Power Supplies (UPS), the Serial Line Internet
Protocol (SLIP), and Modem.

INTRODUCTION
Page 1-4
RMON MIB Support
The TRXI supports the RMON MIB RFC 1271/1513 Token Ring
Extensions shown in Table 1-1.
Token Ring Port Interface Modules (TPIMs)
TPIMs are optional features that let you expand your trunk
connections using different media types.TPIMs have embedded
repeaters and retime all data. Cabletron offers a variety of TPIMs for
trunk Ring In or Ring Out connections.Table 1-2 lists each TPIM.
Table 1-1. RMON MIB RFC 1271/1513 Support
Group Subgroup Section
Statistics
rmon 1 Token Ring ML Stats Table statistics 2
History
rmon 2 History Control Table history 1
Token Ring ML History Table history 3
Alarm
rmon 3 Alarm Table Alarm 1
Event
rmon 9 Event Table event 1
Log Table event 2
Token Ring
rmon 10 Ring Station Control Table token ring 1
Ring Station Table token ring 2
Ring Station Order Table token ring 3
Ring Station Config Control Table token ring 4
Ring Station Config Table token ring 5
Table 1-2. TPIMs
TPIM Media Type Connector
TPIM-T1 Shielded Twisted Pair DB9
TPIM-T2 Unshielded Twisted Pair RJ45
TPIM-T4 Shielded Twisted Pair RJ45
TPIM-F2 Multimode Fiber Optic ST
TPIM-F3 Single mode Fiber Optic ST

INTRODUCTION
Page 1-5
Flash EEPROMs
The TRXI uses Flash EEPROMs that allow you to download new and
updated firmware using Cabletron’s Remote LANVIEW/Windows,
version 2.3 or later or any device using BOOTP or TFTP protocols.
Cabletron’s Distributed LAN Monitor
Cabletron Systems’ Distributed LAN Monitor (DLM) is a software
option for the TRXI. DLM provides a method for locally polling and
monitoring devices on a local area network to minimize network
management traffic on an enterprise, campus, or wide area network.
1.5 REMOTE NETWORK MANAGEMENT CAPABILITIES
You can control and manage the TRXI using any Simple Network
Management Protocol (SNMP) software. Cabletron Systems offers the
following remote management packages:
• Cabletron Systems SPECTRUM
®
• Cabletron Systems Remote LANVIEW
®
/Windows™
• Cabletron Systems Remote SPECTRUM
®
Portable
Management Applications
The TRXI remote network management capabilities provide the
necessary management tools for the TRXI to operate at its full
capacity.Your ability to set up parameters with network management
ensures optimal performance of the TRXI.
1.6 RECOMMENDED READING
We recommend the following publications if you need more
information about implementing a token ring network.
Local Area Networks, Token Ring Access Method, IEEE
Standard 802.5 (1989)
Commercial Building Wiring Standard, EIA Standard
Proposal No. 1907-B (if approved, to be published as EIA/TIA-568 )
LAN Troubleshooting Handbook , Mark Miller (1989, M&T
Publishing)

REQUIREMENTS/SPECIFICATIONS
Page 2-1
CHAPTER 2
REQUIREMENTS/SPECIFICATIONS
This chapter describes cable requirements, power requirements, and
operating specifications for the TRXI. Be sure that you read this
chapter before you install the TRXI. Your network must meet the
requirements and conditions specified in this chapter to obtain
satisfactory performance from this equipment. Failure to follow these
guidelines could result in poor network performance.
2.1 CABLE SPECIFICATIONS
The basic concept of a token ring is a set of Trunk Coupling Units
(TCUs) connected by trunk cabling.You can extend the trunk cabling
by installing TPIMs into the TRXI’s RI/RO ports.TPIMs have
embedded repeaters and provide trunk connections for UTP, STP,
Multimode Fiber, and Single Mode Fiber cabling.
You attach stations to the TCU lobe ports with lobe cabling. Figure 2-1
shows the various ports and cables.
Figure 2-1. TRXI Ports/Cables
Lobe Cabling
Trunk Cabling
Token Ring Station
TRXI-24 TOKEN RING HUB WITH LANVIEW®
RI
RO
TRXI-24 TOKEN RING HUB WITH LANVIEW®
RI
RO
Ring In TPIM
Ring Out TPIM
TCU Lobe Ports

REQUIREMENTS/SPECIFICATIONS
Page 2-2
2.1.1 UTP Cable Specifications for the TRXI-22/24 Lobe Ports
and TPIM-T2
The TRXI-22 and TRXI-24 lobe ports and the TPIM-T2 support voice
grade Unshielded Twisted Pair (UTP) cable, as described in EIA/TIA
TSB 568, and IBM Type 3 cable.
UTP consists of four pairs of 24 AWG solid wire for data or voice
communication and is typically used to wire cable runs within the
walls of buildings. In some installations, existing UTP building wiring
can be used for token ring cabling. UTP cable must conform to the
limits shown in Table 2-1.
Warning :DONOT connectUTPcablingtoany non-tokenringnetwork
conductors (telephone, etc.) or ground. If in doubt, test wiring before
using. Telephone Battery and Ringing voltages, used in UTP telephone
circuits, could present a shock hazard and can damage token ring
equipment when connected to token ring cabling.
The increased popularity and cost advantages of UTP cable have
driven refinements to UTP cable design.As a result, better grades of
UTP cable, known as supergrade or level 4, are available that exhibit
improved transmission characteristics.These improved grades of UTP
can often be used to permit operation at 16 Mbps on longer lobe cables.
Attenuation and Impedance
The values listed inTable 2-1 include the maximum attenuation of the
cables, connectors, patch panels, and reflection losses due to
impedance mismatches in the segment.
Table 2-1. UTP Voice Grade and Category 3 Specifications
Frequency Impedance Attenuation
1 MHz 100 Ω ± 15% <26 dB/km (8 dB/1000 ft)
4 MHz 100 Ω ± 15% <56 dB/km (16 dB/1000 ft)
10 MHz 100 Ω ± 15% <98 dB/km (30 dB/1000 ft)
16 MHz 100 Ω ± 15% <131 dB/km (40 dB/1000 ft)

REQUIREMENTS/SPECIFICATIONS
Page 2-3
Maximum Lobe Lengths
The lobe length is the physical length of the cable connecting a station
to its TCU port at the TRXI.Table 2-2 shows the maximum lobe
length, according to ring speed. The cable lengths listed in Table 2-2
are total lengths made up of UTP cable only.
Type 3 Media Filters
To connect a UTP lobe segment from a TRXI-22 or TRXI-24 to a
station supporting STP cabling, you need a Type 3 Media Filter.
Cabletron Systems offers the following Type 3 Media Filters:
• TRMF ,RJ45 (UTP) connector to 10-inch DB9 (STP) cable with
LANVIEW
• TRMF-2 , RJ45 (UTP) connector to DB9 (STP) connector
Maximum Number of Stations
When you use UTP lobe cabling anywhere on the ring, the number of
stations is limited to 100 stations at ring speeds of either
4 or 16 Mbps.
Table 2-2. UTP Maximum Lobe Lengths
UTP Cable Type Maximum Lobe Length
4 Mbps 16 Mbps
Category 3 100 meters 60 meters
(330 feet) (198 feet)
Category 4 100 meters 60 meters
(330 feet) (198 feet)
Category 5 130 meters 85 meters
(429 feet) (280.5 feet)

REQUIREMENTS/SPECIFICATIONS
Page 2-4
2.1.2 STP Cable Specifications For The TRXI-42/44 Lobe Ports
and TPIM-T1/T4
The TRXI-42 and TRXI-44 lobe ports support IBM Type 1, 2, 6, and 9
STP cabling as described below:
• IBM Type 1 - Two STP lengths of 22 AWG solid wire for data.
Used for the longest cable runs within the walls of buildings.
• IBM Type 2 - Similar to Type 1 data cable, but having four
additional UTP lengths of 22AWG solid wire carried outside of
the shield casing.Typically used for voice communication and
often used to wire cable runs within the walls of buildings.
• IBM Type 6 - Two STP lengths 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).
•
IBM 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).
Attenuation and Impedance
The attenuation values shown in Table 2-3 include the attenuation of
the cables, connectors, patch panels, and reflection losses due to
impedance mismatches in the segment.
Table 2-3. STP Cable Specifications
Frequency Impedance Attenuation
Types 1 & 2
4 MHz
16 MHz 150
Ω + 15%
150 Ω + 15% <22 dB/km (6.7 db/1000 ft.) <45 dB/km (13.7 db/1000 ft.)
Types 6 & 9
4 MHz
16 MHz 150
Ω + 15%
150 Ω + 15% <33 dB/km (10 db/1000 ft.) <66 dB/km (20 db/1000 ft.)

REQUIREMENTS/SPECIFICATIONS
Page 2-5
Maximum Lobe Lengths
The lobe length is the physical length of the cable connecting a station
to its TCU port at the TRXI.Table 2-4 shows the maximum lobe
length, according to ring speed. The cable lengths listed in Table 2-4
are total lengths made up of STP cable only.
Maximum Trunk Lengths
The maximum trunk cable length between the TRXI and another
active device is equal to the maximum drive distance as shown in
Table 2-5.When the neighboring token ring device is a passive device,
the combined length of twice the longest trunk cable plus the longest
lobe cable attached to the passive ring segment cannot exceed the
Maximum Drive Distance.
Maximum Number of Stations
When you use STP lobe cabling everywhere on the ring, the TRXI can
support up to 250 stations at ring speeds of either 4 or 16 Mbps.
Table 2-4. STP Maximum Lobe Lengths
STP Cable Type Ring Speed
4 Mbps 16 Mbps
IBM Types 1 & 2 200 meters 100 meters
(660 feet) (330 feet)
IBM Types 6 & 9 (only
for station to wall jack
and patch panels)
30 meters 30 meters
(99 feet) (99 feet)
Table 2-5. STP Maximum Drive Distance
STP Cable Type Ring Speed
4 Mbps 16 Mbps
IBM Types 1 & 2 770 meters 346 meters
(2525 feet) (1138 feet)
IBM Types 6 & 9 513 meters 230 meters
(1683 feet) (755 feet)

REQUIREMENTS/SPECIFICATIONS
Page 2-6
2.1.3 Mixed Cable Types
If you mix cable types in your installation, you must compensate for
the different cable attenuations.Type 6 and Type 9 cables can be run
for only 2/3 the distance of Type 1. This means:
10 meters (Type 1) ≈ 6.6 meters (Types 6, 9)
Example: Maximum Length for Mixed Cabling Installation
- 16 Mbps ring speed and 130 stations.
- The building has 60 meters of Type 1 cable in the wall.
- How much Type 6 cable is available to connect the repeater
TCU port to the patch panel and the station to the local
wall jack?
- Type 6 can only go 2/3 the distance of Type 1.
Solution:
100 meters = maximum cable length if only Type 1 cable is used
[60 meters of Type 1] + [40 meters of Type 1] = max. length
[60 meters of Type 1] + [(.66) x (40 meters) of Type 6] = max. length
|
|
26.4 meters of Type 6 (for patch panel and wall jack
connections)

REQUIREMENTS/SPECIFICATIONS
Page 2-7
2.1.4 Multimode Fiber Optic Cable Specifications for the
TPIM-F2
Table 2-6 shows Multimode Fiber Optic Cable specifications for the
TPIM-F2.
Maximum Trunk Lengths
The maximum trunk cable length between the TRXI and another
active device is equal to the maximum drive distance as shown in
Table 2-6.When the neighboring token ring device is a passive device,
the combined length of twice the longest trunk cable plus the longest
lobe cable attached to the passive ring segment cannot exceed the
Maximum Drive Distance Trunk Length.
Attenuation
The fiber optic cable must be tested with a fiber optic attenuation test
set that is adjusted for an 850 nm wavelength.This test verifies that
the signal loss in a cable is within an acceptable level.Table 2-6 shows
the attenuation for each Multimode cable type.
Fiber Optic Budget
When determining the maximum fiber optic cable length, the fiber
optic budget delay should be calculated and taken into consideration
before fiber optic cable runs are incorporated in any network design.
Fiber optic budget is the combination of the optical loss due to the
fiber optic cable, in-line splices, and fiber optic connectors.
Table 2-6. Multimode Fiber Optic Cable Specifications
Cable Type Attenuation Maximum Drive Distance
50/125 µ m 13.0 dB or less The maximum allowable fiber op-
tic cable length is 2 km (2187.2
yards). However, IEEE 802.5
specifications allow for a maxi-
mum of 1 km (1093.6 yards).
62.5/125 µ m 16.0 dB or less
100/140 µ m 19.0 dB or less

REQUIREMENTS/SPECIFICATIONS
Page 2-8
2.1.5 Single Mode Fiber Optic Cable Specifications for the
TPIM-F3
Table 2-7 shows Single Mode Fiber Optic Cable specifications for the
TPIM-F3.
Maximum Trunk Lengths
The maximum trunk cable length between the TRXI and another
active device is equal to the Maximum Drive Distance as shown in
Table 2-7.When the neighboring token ring device is a passive device,
the combined length of twice the longest trunk cable plus the longest
lobe cable attached to the passive ring segment cannot exceed the
Maximum Drive Distance Trunk Length.
Attenuation
The fiber optic cable must be tested with a fiber optic attenuation test
set that is adjusted for a 1300 nm wavelength.This test verifies that
the signal loss in a cable is within an acceptable level of 10 dB or less
for any given single mode fiber optic link.
Fiber Optic Budget
Fiber optic budget is the combination of the optical loss due to the
fiber optic cable, in-line splices, and fiber optic connectors.When
determining the maximum fiber optic cable length, the fiber optic
budget (total loss of 10.0 dB or less between stations) should be
calculated and considered before fiber optic cable runs are
incorporated in any network design.
Table 2-7. Single Mode Fiber Optic Cable Specifications
Cable Type Attenuation Maximum Drive Distance
8/125-12/125 µ m 10.0 dB or less The maximum allowablefiber
optic cable length is 2 km
(2187.2 yards). However,
IEEE 802.5 specifications al-
low for a maximum of 1 km
(1093.6 yards).

REQUIREMENTS/SPECIFICATIONS
Page 2-9
2.2 CABLE RECOMMENDATIONS/TROUBLESHOOTING
The following sections describe common cable problems and
recommendations for correcting them.
Crosstalk
Crosstalk is interference caused by signal coupling between the
different cable pairs contained within a multi-pair cable bundle.
Multi-pair cables should not be used for UTP lobe cabling. UTP lobe
cabling should be dedicated to carrying token ring traffic.Avoid
mixing token ring signals with other applications (voice, etc.) within
the same cable.
Noise
Noise can be caused by either crosstalk or externally induced
impulses. If noise induced errors are suspected, it may be necessary to
reroute cabling away from potential noise sources (motors, switching
equipment, fluorescent lighting, high amperage equipment), or to
ensure that the electrical wiring in the area is properly wired and
grounded.
Temperature
The attenuation of PVC insulated cable varies significantly with
temperature. Plenum-rated cables are strongly recommended at
temperatures greater than 40˚C to ensure that cable attenuation
remains within specification. Check the cable manufacturer’s
specifications.
In addition to complying with the preceding cable specifications, the
following recommendations should be followed to minimize errors and
help to obtain optimum performance from your network:
• UTP cabling should be free of splices, stubs or bridged taps.
• No more than two punch-down blocks between TCU ports and
wall outlets.
• Metal troughs,ducts,etc.carrying token ring signals should be
properly grounded.