Cabletron Systems HubSTACK SEHI-34 User manual

SEHI-22, SEHI-24, SEHI-32, AND SEHI-34
10BASE-T INTELLIGENT STACKABLE HUB
USER’S GUIDE
CABLETRON SYSTEMS, P. O. Box 5005, Rochester, NH 03867-0505
The Complete Networking Solution™

NOTICE
i
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 February 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: 9030916-01 February 94
SPECTRUM
®
, LANVIEW
®
, Remote LANVIEW
®
,and HubSTACK
™
aretrademarks
of Cabletron Systems, Inc.
IBM is a registered trademark of International Business Machines Corporation.
i960 is a registered trademark of Intel Corporation.
DEC , VT200 , and VT300 are trademarks of Digital Equipment Corporation.
Ethernet is a trademark of Xerox Corporation.
CompuServe is a registered trademark of CompuServe, Inc.
Windows is a registered trademark of Microsoft Corporation.
Printed On Recycled Pa
per

NOTICE
ii
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.

NOTICE
iii
CABLETRON SYSTEMS, INC.
PROGRAM LICENSE AGREEMENT
IMPORTANT: Before utilizing this product, carefully read this License Agreement.
This document is an agreement between you, the end user, and Cabletron Systems, Inc.
(“Cabletron”) that sets forth your rights and obligations with respect to the Cabletron
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CABLETRON SOFTWARE PROGRAM LICENSE
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the personal jurisdiction and venue of the New Hampshire courts.

NOTICE
iv
EXCLUSION OF WARRANTY
AND DISCLAIMER OF LIABILITY
1. EXCLUSION OF WARRANTY. Except as may be specifically provided by
Cabletron in writing, Cabletron makes no warranty, expressed or implied,
concerning the Program (including Its documentation and media).
CABLETRON DISCLAIMS ALL WARRANTIES, OTHER THAN THOSE
SUPPLIED TO YOU BY CABLETRON IN WRITING, EITHER EXPRESS OR
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WHATSOEVER (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS
OF BUSINESS, PROFITS, BUSINESS INTERRUPTION, LOSS OF BUSINESS
INFORMATION, SPECIAL, INCIDENTAL, CONSEQUENTIAL, OR RELIANCE
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ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. BECAUSE SOME
STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY
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OR LIMITATION OF IMPLIED WARRANTEES IN SOME INSTANCES THE
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UNITED STATES GOVERNMENT
RESTRICTED RIGHTS
The enclosed product (a) was developed solely at private expense; (b) contains “restricted
computer software” submitted with restricted rights in accordance with Section 52227-
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its successors, and (c) in all respects is proprietary data belonging to Cabletron and/or its
suppliers.
For Department of Defense units, the product is licensed with “Restricted Rights” as
defined in the DoD Supplement to the Federal Acquisition Regulations, Section 52.227-
7013 (c) (1) (ii) and its successors, and use, duplication, disclosure by the Government is
subject to restrictions as set forth in subparagraph (c) (1) (ii) of the Rights in Technical
Data and Computer Software clause at 252.227-7013. Cabletron Systems, Inc., 35
Industrial Way. Rochester, New Hampshire 03867

CONTENTS
v
TABLE OF CONTENTS
APPENDIX A TABLE OF CONTENTS v
CHAPTER 1 INTRODUCTION
1.1 USING THIS MANUAL............................................................1-1
1.2 GETTING HELP........................................................................1-2
1.3 SEHI OVERVIEW .....................................................................1-2
1.4 SEHI FEATURES......................................................................1-3
1.5 STACKABLE CAPABILITIES..................................................1-4
1.6 REMOTE NETWORK MANAGEMENT CAPABILITIES ......1-4
1.7 OPTIONAL FEATURES ...........................................................1-5
1.8 RELATED MANUALS ..............................................................1-6
CHAPTER 2 INSTALLATION
REQUIREMENTS/SPECIFICATIONS
2.1 CABLE SPECIFICATIONS.......................................................2-1
2.1.1 HubSTACK Interconnect Cable Requirements...........2-1
2.1.2 UTP and STP Cable Specifications for the Network Ports
and EPIM-T Module......................................................2-2
2.1.3 Multimode Fiber Optic Cable Specifications for the
EPIM-F1 and EPIM-F2 Modules .................................2-4
2.1.4 Single Mode Fiber Optic Cable Specifications for
the EPIM-F3 Module ....................................................2-5
2.1.5 Thin-Net Network Requirements for the EPIM-C Mod-
ule 2-6
2.1.6 AUI Cable Requirements for the EPIM-A
and EPIM-X Modules....................................................2-7
2.2 NETWORK PORT SPECIFICATIONS ....................................2-7
2.2.1 SEHI-22 and SEHI-24 Network Port Specifications...2-8
2.2.2 SEHI-32 and SEHI-34 Network Port Specifications...2-8
2.3 EPIM SPECIFICATIONS .......................................................2-10
2.3.1 EPIM-T........................................................................2-10
2.3.2 EPIM-F1 and EPIM-F2.............................................2-11
2.3.3 EPIM-F3......................................................................2-12
2.3.4 EPIM-C........................................................................2-14
2.3.5 EPIM-A and EPIM-X (AUI Port)................................2-15
2.4 COM PORT REQUIREMENTS ..............................................2-16
2.5 TRANSCEIVER REQUIREMENTS.......................................2-16

CONTENTS
vi
2.6 OPERATING SPECIFICATIONS...........................................2-17
CHAPTER 3 INSTALLATION
3.1 UNPACKING THE SEHI ..........................................................3-1
3.2 INSTALLING THE SEHI..........................................................3-1
3.2.1 Stacking the SEHI.........................................................3-2
3.2.2 Attaching the Strain Relief Bracket.............................3-4
3.2.3 Rack Mounting the SEHI..............................................3-5
3.2.4 Wall Mounting the SEHI ..............................................3-6
3.2.5 Free-Standing Installation............................................3-7
3.3 CONNECTING THE SEHI TO THE POWER SOURCE.........3-8
CHAPTER 4 CONNECTING TO THE NETWORK
4.1 CONNECTING THE SEHI TO THE NETWORK....................4-1
4.1.1 Connecting to Network Ports, SEHI-22 and SEHI-24 4-1
4.1.2 Connecting to Network Ports, SEHI-32 and SEHI-34 4-3
4.1.3 Connecting a UTP Segment to an EPIM-T..................4-4
4.1.4 Connecting a Fiber Optic Link Segment to an EPIM-F1,
EPIM-F2, or EPIM-F34-5
4.1.5 Connecting a Thin-Net Segment to an EPIM-C ..........4-8
4.1.6 Connecting an AUI Cable to an EPIM-A ...................4-10
4.1.7 Connecting an AUI Cable to an EPIM-X....................4-11
4.2 FINISHING THE INSTALLATION........................................4-12
CHAPTER 5 TROUBLESHOOTING
5.1 INSTALLATION CHECK-OUT ................................................5-1
5.2 USING LANVIEW......................................................................5-2
5.3 USING THE RESET BUTTON.................................................5-4
CHAPTER 6 LOCAL MANAGEMENT
6.1 MANAGEMENT TERMINAL REQUIREMENTS...................6-2
6.1.1 Console Cable Configuration ........................................6-3
6.1.2 Management Terminal Setup Parameters...................6-4
6.2 ACCESSING LOCAL MANAGEMENT....................................6-5
6.3 USING THE LOCAL MANAGEMENT SCREENS..................6-7
6.3.1 The Community Name Table Screen............................6-7
6.3.2 The Configuration Screen...........................................6-10
6.3.3 The Trap Table Screen................................................6-14
6.3.4 The SNMP Tools Screen..............................................6-16
6.3.5 The Device Statistics Screen.......................................6-22

CONTENTS
vii
APPENDIX B TWISTED PAIR WIRING TABLES A-1

INTRODUCTION
Page 1-1
CHAPTER 1
INTRODUCTION
Welcome to the Cabletron Systems SEHI-22, SEHI-24, SEHI-32,
and SEHI-34 10BASE-T Intelligent Stackable Hub User’s
Guide . This manual explains installation instructions and provides
reference information for the SEHI-22, 24, 32, and 34.
Note : The term SEHI (Stackable Ethernet Hub with Intelligence) is
used throughout this manual when describing features and functions
that are common to the SEHI-22, 24, 32, and 34.
1.1 USING THIS MANUAL
Read through this manual to gain an understanding of the features
and capabilities of the SEHI.A general knowledge of Ethernet and
IEEE 802.3 type data communications networks and their physical
layer components will be helpful when installing the SEHI.
Chapter 1,
Introduction ,outlines the contents of this manual, briefly
describes SEHI features, and concludes with a list of related manuals.
Chapter 2, Installation Requirements/Specifications , describes
installation requirements, network guidelines, and SEHI operating
specifications.
Chapter 3, Installation , contains instructions for installing your
SEHI as a stackable or stand-alone hub.
Chapter 4, Connecting to the Network ,explains how to connect the
SEHI to the network using the various media types.
Chapter 5, Troubleshooting, describes how to use the LANVIEW
LEDs to troubleshoot network problems.
Chapter 6, Local Management , describes how to use SEHI Local
Management screens and the available commands.
Appendix A, Twisted Pair Wiring Tables , lists Punch Down Block
pinouts.

INTRODUCTION
Page 1-2
1.2 GETTING HELP
If you need additional support related to the Cabletron Systems SEHI,
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]
By FTP.....................ctron.com (134.141.197.25)
Login: anonymous , Password: your email address
1.3 SEHI OVERVIEW
The 10BASE-T SEHI is an intelligent repeating hub that provides
front panel ports for network connections and a rear panel
HubSTACK Interconnect Bus port for stackable connections.The
SEHI is designed to manage Cabletron Systems’ SEH series of
non-intelligent stackable hubs.
Figure 1-1. The SEHI-24 and SEHI-34
SEH INTERCONNECT
OUT
SEHI-24 10BASE-T HUB WITH LANVIEW®
EPIM-1
EPIM-2
PWR
CPU
CLN E
1
E
2
RCV
LNK
RCV
LNK
HubSTACK 10BASE-T HUB WITH LANVIEW®
SEHI-24
24X 23X 22X 21X 20X 19X 18X 17X 16X 15X 14X 13X
12X 11X 10X 9X 8X 7X 6X 5X 4X 3X 2X 1X
COM
RESET
24 23 22 21 20 19 18 17 16 15 14 13
12 11 10 9 8 7 6 5 4 3 2 1
SEH INTERCONNECT
OUT
SEHI-34 10BASE-T HUB WITH LANVIEW®
EPIM-1
EPIM-2
PWR
CPU
CLN E
1
E
2
RCV
LNK
RCV
LNK
HubSTACK 10BASE-T HUB WITH LANVIEW®
SEHI-34
COM
RESET
24 23 22 21 20 19 18 17 16 15 14 13
12 11 10 9 8 7 6 5 4 3 2 1
12X 1X
24X 13X

INTRODUCTION
Page 1-3
The SEHI-22/24 and SEHI-32/34 are functionally identical with the
exception of the network ports:
• SEHI-22 , 12 RJ45 network ports and one EPIM port.
• SEHI-24 , 24 RJ45 network ports and two EPIM ports.
• SEHI-32 , one 50 pin Champ connector, providing 12 twisted
pair segments, and one EPIM port.
• SEHI-34 , two 50 pin Champ connectors, providing 24 twisted
pair segments, and two EPIM ports.
1.4 SEHI FEATURES
Repeater Functionality
The SEHI fully conforms to the IEEE 802.3 Repeater,AUI, and
10BASE-T specifications, and provides the flexibility to connect
networks using IEEE 802.3, Ethernet Version 1 or Version 2
equipment.The SEHI transmits re-timed data packets, regenerates
the preamble, extends fragments, and arbitrates collisions.
The SEHI automatically partitions problem segments, and reconnects
repaired segments to the network.This feature minimizes the impact
on network operation resulting from a problem on one segment by
isolating the problem segment. Only devices on the problem segment
are affected.When the problem is solved, the SEHI automatically
reconnects the isolated segment to the network.
Polarity Detection and Correction
Each twisted pair port on the SEHI incorporates a Polarity Detection
and Correction feature that allows the SEHI to pass data regardless of
the polarity of the twisted pair segment’s receive link.We do not
recommend operating in this condition. If you discover this condition,
remove the segment from the network and wire it correctly.This
reduces the potential for problems if equipment changes are made.
Flash EEPROMs
The SEHI 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.

INTRODUCTION
Page 1-4
LANVIEW LEDs
Cabletron Systems’ LANVIEW Status Monitoring and Diagnostics
System is a troubleshooting tool that helps you diagnose power
failures, collisions, cable faults, and link problems.The LANVIEW
LEDs are conveniently located on the SEHI’s front panel.
Reset Button
The front panel Reset Button lets you reboot the SEHI and initialize
the processor.
Local Management
The SEHI’s Local Management lets you manage the SEHI and all its
attached segments. It also provides full packet and error statistics for
the entire stack,individual device, or individual port.You access Local
Management by attaching a DEC VT™ 320 terminal or a PC using
VT320 emulation software to the SEHI’s RJ45 COM port.
1.5 STACKABLE CAPABILITIES
The SEHI intelligent hub is designed to manage Cabletron’s SEH
series of non-intelligent hubs.The SEHI serves as the logical “top” of
the stack. It manages all SEH hubs in the stack providing full packet
and error statistics for the entire stack, individual device, or
individual port.
You can stack together up to four SEH non-intelligent hubs with one
SEHI using Cabletron’s external HubSTACK Interconnect cables.
Stackable configurations let you maintain only one IEEE repeater hop
while providing up to 130 Ethernet ports.You can also add or remove
hubs from the stack without having to power down.
1.6 REMOTE NETWORK MANAGEMENT CAPABILITIES
You can manage the SEHI remotely by any SNMP network
management system. Cabletron Systems offers the following remote
management packages:
• Cabletron Systems SPECTRUM
®
• Cabletron Systems Remote LANVIEW
®
/Windows™
• Cabletron Systems Remote LANVIEW
®
for SunNet™ Manager

INTRODUCTION
Page 1-5
1.7 OPTIONAL FEATURES
The following features are not included with the SEHI but can be
purchased separately from Cabletron Systems.
Ethernet Port Interface Modules (EPIMs)
EPIMs let you expand your network through a variety of media.
Cabletron Systems offers the EPIMs shown in Table 1-1.
HubSTACK Interconnect Cables
You need Cabletron’s HubSTACK Interconnect cables to stack hubs
together.Table 1-2 lists the part number and application for each
cable.
Table 1-1. EPIMs
EPIM Media Type Connector
EPIM-A AUI DB15 (Female)
EPIM-C 10BASE-2 Thin Coaxial BNC
EPIM-T 10BASE-T Unshielded
Twisted Pair RJ45
EPIM-X Standard Transceiver DB15 (Male)
EPIM-F1 Multimode Fiber SMA
EPIM-F2 Multimode Fiber ST
EPIM-F3 Single Mode Fiber ST
Table 1-2. HubSTACK Interconnect Cables
Part
Number Description Application
9380110 12" HubSTACK
Interconnect Cable SEH to SEH connections.
9380111 18" HubSTACK
Interconnect Cable SEHI to SEH connections.

INTRODUCTION
Page 1-6
Daughter Board Upgrade Kit
You can upgrade the SEHI-22 and the SEHI-32 to 24 ports using the
daughter board upgrade kit.The Cabletron part numbers for the
upgrades are:
• SEHI-22: 24PORT-UGKT-E
• SEHI-32: 24PORT-UGKT-E 50P
Rack Mount or Wall Mount Hardware
You can install your SEHI in a 19-inch rack or mount it on a wall.
Cabletron offers an accessory package that includes brackets and
mounting screws.The part number for the accessory package is
SEHI-ACCY-KIT.
1.8 RELATED MANUALS
Use the Cabletron Systems SEH-22/24 and SEH-32/34 User’s
Guide to supplement the procedures and other technical data
provided in this manual.The procedures contained in the SEH-22/24
and SEH-32/34 User’s Guide are referenced where appropriate, but
not repeated in this manual.

INSTALLATION REQUIREMENTS/SPECIFICATIONS
Page 2-1
CHAPTER 2
INSTALLATION
REQUIREMENTS/SPECIFICATIONS
This Chapter describes cabling requirements, network guidelines,and
operating specifications for the SEHI. Be sure to read this chapter
before you install the SEHI.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 SEHI network ports support both Shielded Twisted Pair (STP) or
Unshielded Twisted Pair (UTP) cabling.The Ethernet Port Interface
Modules (EPIMs) let you expand your network using UTP, STP,
Multimode Fiber Optic, Single Mode Fiber Optic, or Thin Coaxial
cabling.The rear panel Interconnect Bus port supports Cabletron
Systems’ HubSTACK Interconnect cables for stackable applications.
Take care in planning and preparing the cabling and connections for
your network.The quality of the connections and the length of cables
are critical factors in determining the reliability of your network.The
following sections describe specifications for each media type.
2.1.1 HubSTACK Interconnect Cable Requirements
You stack the SEHI to modules in the stack with the SEHI
HubSTACK Interconnect cable available only from Cabletron
Systems.Refer to Chapter 1 for cable part numbers.The cable attaches
to the SEHI’s rear panel bus port.
The rear panel of the SEHI has an Interconnect Bus Out port (male
connector) to stack SEH non-intelligent hubs together. You can stack
as many as four SEH’s together with one SEHI.

INSTALLATION REQUIREMENTS/SPECIFICATIONS
Page 2-2
2.1.2 UTP and STP Cable Specifications for the Network Ports
and EPIM-T Module
The device at the other end of the twisted pair segment must meet
IEEE 802.3 10BASE-T specifications.When you connect a 10BASE-T
Twisted Pair Segment to the SEHI’s 10BASE-T Twisted Pair Network
Ports and EPIM-T module, your network must meet the following
requirements:
Length
The IEEE 802.3 10BASE-T standard requires that 10BASE-T devices
transmit over a 100 meter (328 foot) link using 22-24 AWG unshielded
twisted pair wire. However, cable quality largely determines
maximum link length. If you use high quality, low attenuation cable,
you can achieve link lengths of up to 200 meters. Cable delay limits
maximum link length to 200 meters, regardless of the cable type.
Insertion Loss
The maximum insertion loss allowed for a 10BASE-T link is 11.5 dB
at all frequencies between 5.0 and 10 MHz.This includes the
attenuation of the cables, connectors, patch panels, and reflection
losses due to impedance mismatches in the link segment.
Impedance
Cabletron Systems 10BASE-T Twisted Pair products will work on
twisted pair cable with 75 to 165 ohms impedance.Unshielded twisted
pair cables typically have an impedance of between 85 to 110 ohms.
Shielded twisted pair cables, such as IBM Type 1 cable, can also be
used.You should remember that the impedance of IBM Type 1 cable is
typically 150 ohms.This increases the signal reflection caused by the
cable, but since the cable is shielded, this signal reflection has little
effect on the received signal’s quality due to the lack of crosstalk
between the shielded cable pairs.
Jitter
Intersymbol interference and reflections can cause jitter in the bit cell
timing, resulting in data errors.A 10BASE-T link must not generate
more than 5.0 nsec. of jitter. If your cable meets the impedance
requirements for a 10BASE-T link, jitter should not be a concern.

INSTALLATION REQUIREMENTS/SPECIFICATIONS
Page 2-3
Delay
The maximum propagation delay of a 10BASE-T link segment must
not exceed 1000 nsec.This 1000 nsec. maximum delay limits the
maximum link segment length to no greater than 200 meters.
Crosstalk
Crosstalk is caused by signal coupling between the different cable
pairs contained within a multi-pair cable bundle. 10BASE-T
transceivers are designed so that the user does not need to be
concerned about cable crosstalk, provided the cable meets all other
requirements.
Noise
Noise can be caused by either crosstalk or externally induced
impulses.Impulse noise may cause data errors if the impulses occur at
very specific times during data transmission. Generally, the user need
not be concerned about noise. If noise-related data errors are
suspected, it may be necessary to either reroute the cable or eliminate
the source of the impulse noise.
Temperature
Multi-pair PVC 24 AWG telephone cables typically have an
attenuation of approximately 8 to 10 dB/100m at 20 ° C (78 ° F).The
attenuation of PVC insulated cable varies significantly with
temperature.At temperatures greater than 40 ° C (104 ° F), we
strongly recommend that you use plenum-rated cables to ensure that
cable attenuation remains within specification.

INSTALLATION REQUIREMENTS/SPECIFICATIONS
Page 2-4
2.1.3 Multimode Fiber Optic Cable Specifications for the
EPIM-F1 and EPIM-F2 Modules
Table 2-1 shows Multimode Fiber Optic Cable specifications for the
EPIM-F1 and EPIM-F2 modules.
Attenuation
You must test the fiber optic cable with a fiber optic attenuation test
set adjusted for an 850 nm wavelength. This test verifies that the
signal loss in a cable is within an acceptable level.Table 2-1 shows the
attenuation for each Multimode cable type.
Fiber Optic Budget and Propagation Delay
When determining the maximum fiber optic cable length, the fiber
optic budget delay and total network propagation 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.
Propagation delay is the amount of time it takes data to travel from
the sending device to the receiving device.Total propagation delay
allowed for the entire network is 25.6 µsec, if the total propagation
delay between any two nodes on the network exceeds 25.6 µsec, then
bridges should be used.
Table 2-1. Multimode Fiber Optic Cable Specifications
Cable Type Attenuation Maximum Cable Length
50/125 µm 13.0 dB or less The maximum allowable fiber
optic cable length is 2 km
(2187.2 yards). However,
IEEE 802.3 specifications
allow for a maximum of 1 km
(1093.6 yards).
62.5/125 µm 16.0 dB or less
100/140 µm 19.0 dB or less

INSTALLATION REQUIREMENTS/SPECIFICATIONS
Page 2-5
2.1.4 Single Mode Fiber Optic Cable Specifications for
the EPIM-F3 Module
Table 2-2 shows Single Mode Fiber Optic Cable specifications for the
EPIM-F3.
Attenuation
You must test the fiber optic cable with a fiber optic attenuation test
set adjusted for an 1300 nm wavelength. This test verifies that the
signal loss in a cable is 10.0 dB or less for any given single mode fiber
optic link.
Fiber Optic Budget and Propagation Delay
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) and total
network propagation delay should be calculated and considered before
fiber optic cable runs are incorporated in any network design.
Propagation delay is the amount of time it takes data to travel from
the sending device to the receiving device.Total propagation delay
allowed for the entire network is 25.6 µsec, if the total propagation
delay between any two nodes on the network exceeds 25.6 µsec, then
bridges should be used.
Table 2-2. Single Mode Fiber Optic Cable Specifications
Cable Type Attenuation Maximum Cable Length
8/125-12/125 µm 10.0 dB or less The maximum allowable fiber
optic cable length is
5 km (3.1 miles) with bridges
at each segment end. Howev-
er, IEEE 802.3 FOIRL specifi-
cations specify a maximum of
1 km (1093.6 yards).

INSTALLATION REQUIREMENTS/SPECIFICATIONS
Page 2-6
2.1.5 Thin-Net Network Requirements for the EPIM-C Module
When you connect a thin-net segment to the SEHI (via an EPIM-C),
your network must meet the following requirements:
Cable Type
50 ohm RG-58A/U type coaxial cable must be used when making up a
thin-net cable segment.
Length
The thin-net segment must be no longer than 185 meters.
Terminators
A 50 ohm terminator must be connected to the far end of each
thin-net segment.
Connectors
A maximum of 29 tee-connectors may be used throughout the length
of cable segment for host connections. If an excessive number of barrel
connectors are used within the cable segment, such as finished wall
plates with BNC feed-throughs, then a reduced number of host
connections may be required. For special network design, contact
Cabletron Systems Technical Support.
Grounding
For safety, ground only one end of a thin-net segment. Do NOT
connect EPIM BNC ports to earth ground.
Warning: Connecting a thin-net segment to earth ground at more than
one point could produce dangerous ground currents.