Cabletron Systems BRIM-E6 User manual

BRIM-E6
USER’S GUIDE
CABLETRON SYSTEMS, P. O. Box 5005, Rochester, NH 03866-5005

BRIM-E6 USER’S GUIDE 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.
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 MANUAL OR THE INFORMATION CONTAINED
IN IT, EVEN IF CABLETRON SYSTEMS HAS BEENADVISED OF, KNOWN, OR
SHOULD HAVE KNOWN, THE POSSIBILITY OF SUCH DAMAGES.
© Copyright August 1994 by:
Cabletron Systems, Inc., P.O. Box 5005, Rochester, NH 03866-5005
All Rights Reserved
Printed in the United States of America
Part Number: 9031027August 1994
LANVIEW is a registered trademark of Cabletron Systems, Inc.
MicroMMAC and BRIM are trademarks of Cabletron Systems, Inc.
Windows is a registered trademark of Microsoft Corp.
Ethenet is a trademark of Xerox Corp.
CompuServe is a registered trademark of CompuServe
Printed On Recycled Paper

NOTICE
ii BRIM-E6 USER’S GUIDE
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 ClassA
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 ClassA 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
BRIM-E6 USER’S GUIDE 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
software program (the “Program”) contained in this package. The Program may be
contained in firmware, chips or other media. BY UTILIZING THE ENCLOSED
PRODUCT,YOU ARE AGREEING TO BECOME BOUND BY THE TERMS OF THIS
AGREEMENT, WHICH INCLUDES THE LICENSEAND THE LIMITATION OF
WARRANTY AND DISCLAIMER OF LIABILITY. IFYOU DO NOT AGREE TO THE
TERMS OF THISAGREEMENT, PROMPTLY RETURN THE UNUSED PRODUCT
TO THE PLACE OF PURCHASE FOR A FULL REFUND.
CABLETRON SOFTWARE PROGRAM LICENSE
1. LICENSE. You have the right to use only the one (1) copy of the Program provided
in this package subject to the terms and conditions of this License Agreement.
You may not copy, reproduce or transmit any part of the Program except as permitted by
the Copyright Act of the United States or as authorized in writing by Cabletron.
2. OTHER RESTRICTIONS. You may not reverse engineer, decompile, or
disassemble the Program.
3. APPLICABLE LAW. This License Agreement shall be interpreted and governed
under the laws and in the state and federal courts of New Hampshire.You accept the
personal jurisdiction and venue of the New Hampshire courts.
EXCLUSION OFWARRANTY 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
TOYOU BY CABLETRON IN WRITING, EITHER EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF
MERCHANTABLITY AND FITNESS FOR A PARTICULAR PURPOSE, WITH
RESPECT TO THE PROGRAM, THE ACCOMPANYING WRITTEN MATERIALS,
AND ANY ACCOMPANYING HARDWARE.

NOTICE
iv BRIM-E6 USER’S GUIDE
2. NO LIABILITY FOR CONSEQUENTIAL DAMAGES. IN NO EVENT SHALL
CABLETRON OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES
WHATSOEVER (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS OF
BUSINESS, PROFITS, BUSINESS INTERRUPTION, LOSS OF BUSINESS
INFORMATION, SPECIAL, INCIDENTAL, CONSEQUENTIAL, OR RELIANCE
DAMAGES, OR OTHER LOSS) ARISING OUT OF THE USE OR INABILITY TO
USE THIS CABLETRON PRODUCT, EVEN IF CABLETRON HAS BEEN ADVISED
OF THE POSSIBILITY OF SUCH DAMAGES. BECAUSE SOME STATES DO NOT
ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR
CONSEQUENTIAL OR INCIDENTAL DAMAGES, OR ON THE DURATION OR
LIMITATION OF IMPLIED WARRANTEES IN SOME INSTANCES THE ABOVE
LIMITATIONSAND EXCLUSIONS MAY NOT APPLY TOYOU.
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 52227-19
(a) through (d) of the Commercial Computer Software - Restricted Rights Clause and 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

BRIM-E6 USER’S GUIDE v
TABLE OF CONTENTS
CHAPTER 1 INTRODUCTION
1.1 USING THIS MANUAL................................................................... 1
1.2 GETTING HELP............................................................................. 2
1.3 BRIM-E6 OVERVIEW..................................................................... 2
1.4 BRIM-E6 FEATURES..................................................................... 2
1.5 BRIM-E6 SPECIFICATIONS.......................................................... 3
1.6 ETHERNET BRIDGING ................................................................. 4
1.7 RELATED MANUALS..................................................................... 6
CHAPTER 2 INSTALLATION
2.1 UNPACKING THE BRIM................................................................ 7
2.2 INSTALLING BRIMs....................................................................... 7
2.2.1 Installing a BRIM-E6 in a MIM........................................... 8
2.2.2 Installing a BRIM in a Hub............................................... 10
2.2.3 Installing an EPIM into the BRIM..................................... 11
CHAPTER 3 CONNECTING TO THE NETWORK
3.1 CONNECTING THE BRIM TO THE NETWORK.......................... 13
3.1.1 Connecting a UTP Segment to an EPIM-T...................... 13
3.1.2 Connecting a Fiber Optic Link Segment to
an EPIM-F1, EPIM-F2, or EPIM-F3................................. 15
3.1.3 Connecting a Thin-Net Segment to an EPIM-C............... 17
3.1.4 Connecting an AUI Cable to an EPIM-A.......................... 19
3.1.5 Connecting an AUI Cable to an EPIM-X.......................... 20
3.2 FINISHING THE INSTALLATION................................................. 21
CHAPTER 4 USING THE LANVIEW LEDS
4.1 STB (Standby).............................................................................. 23
4.2 XMT (Transmit)............................................................................. 23
4.3 CLN (Collision) ............................................................................. 23
4.4 RCV (Receive).............................................................................. 23

CONTENTS
vi BRIM-E6 USER’S GUIDE
APPENDIX A EPIM SPECIFICATIONS
A.1 EPIM-T (10BASE-T TWISTED PAIR PORT)................................25
A.2 EPIM-F1 AND EPIM-F2 (MULTIMODE FIBER OPTIC PORTS)..26
A.3 EPIM-F3 (SINGLE MODE FIBER OPTIC PORT).........................27
A.4 EPIM-C (BNC PORT) ...................................................................29
A.5 EPIM-A AND EPIM-X (AUI PORTS).............................................30
APPENDIX B EPIM CABLE REQUIREMENTS
B.1 CABLE REQUIREMENTS ............................................................31
B.1.1 10BASE-T UTP and STP Cable Requirements...............31
B.1.2 FOIRL/10BASE-FL Multimode Fiber Optic Cable
Requirements...................................................................33
B.1.3 FOIRL/10BASE-FL Single Mode Fiber Optic Cable
Requirements...................................................................34
B.1.4 10BASE-2 Thin-net Cable Requirements ........................35
B.1.5 AUI Cable Requirements .................................................36
INDEX

BRIM-E6 USER’S GUIDE Page 1
CHAPTER 1
INTRODUCTION
Welcome to the Cabletron Systems BRIM-E6 User’s Guide . This
manual explains how to install the Bridge/Router Interface Module
(BRIM) for Ethernet into Cabletron products that support BRIM
technology (e.g., the EMM-E6 or MicroMMAC). It also explains
BRIM-E6 features and specifications.
1.1 USING THIS MANUAL
Read through this manual completely to familiarize yourself with its
content and to gain an understanding of the features and capabilities of
the BRIM-E6.A general working knowledge of Ethernet, and IEEE 802.3
type data communications networks and their physical layer components
is helpful when using the BRIM-E6.
Chapter 1,
Introduction , describes BRIM-E6 features, lists
specifications, and concludes with a list of related manuals.
Chapter 2,
Installation , describes how to install the BRIM-E6 into a
Media Interface Module (MIM) or a stand-alone product. This chapter
also explains how to install an Ethernet Port Interface Module (EPIM)
into the BRIM.
Chapter 3,
Connecting to the Network , explains how to connect network
segments to the EPIM.
Chapter 4,
Using the LANVIEW LEDS , describes how to use the
BRIM-E6 LEDs to monitor BRIM performance and status.
Appendix A,
EPIM Specifications , lists specifications for each of the
EPIMs available for the BRIM-E6.
Appendix B,
EPIM Cable Requirements lists cable requirements for
each of the EPIMs.

CHAPTER 1: INTRODUCTION
Page 2 BRIM-E6 USER’S GUIDE
1.2 GETTING HELP
If you need additional support related to the BRIM-E6, 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 BRIM-E6 OVERVIEW
The BRIM-E6 extends the functionality of your individual MIM or
stand-alone hub to include Ethernet bridging capability. The BRIM-E6
has one user-configurable Ethernet Port Interface Module (EPIM)
interface. Cabletron Systems offers a variety of EPIMs that support
connections for Unshielded Twisted Pair, Shielded Twisted Pair,
Multimode Fiber Optic, Single Mode Fiber Optic, AUI, or Thin Coaxial
cable.
1.4 BRIM-E6 FEATURES
Ethernet Bridging
The BRIM-E6 adds an Ethernet bridged connection to any Cabletron
device with a BRIM expansion port. Refer to section 1.6 for more
information about Ethernet bridging.
MIB Support
For information on how to extract and compile individual MIBs, contact
Cabletron Systems Technical Support (see
Getting Help ).
LANVIEW Diagnostic LEDs
Cabletron equips the BRIM-E6 with a visual diagnostic and monitoring
system called LANVIEW. LANVIEW LEDs help you quickly identify
Bridge and Link status.

BRIM-E6 SPECIFICATIONS
BRIM-E6 USER’S GUIDE Page 3
EPIM Connectivity
EPIMs allow you to configure the BRIM-E6 to support a variety of media
types. Cabletron Systems offers the EPIMs shown in Table 1-1.
1.5 BRIM-E6 SPECIFICATIONS
The operating specifications for the BRIM-E6 are described in this
section. Cabletron Systems reserves the right to change these
specifications at any time without notice.
Environmental Requirements
Operating Temperature: -5 ° to +40 ° C
Non-operating Temperature: -30
° to +90 ° C
Operating Humidity: 5 to 95% (non-condensing)
Safety and Approvals
This unit meets the safety requirements of UL 1950, CSA C22.2 NO 950,
and EN 60950; the EMI requirements of FCC Class A and EN 55022
Class A; and the EMC requirements of EN 50082-1.
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

CHAPTER 1: INTRODUCTION
Page 4 BRIM-E6 USER’S GUIDE
1.6 ETHERNET BRIDGING
Bridging Overview
Ethernet bridges read in packets and make decisions to filter or forward
based on the destination address of the packet. The simple filter/forward
decision process allows a bridge to segment traffic between two networks,
keeping local traffic local. This process increases the availability of each
network while still allowing traffic destined for the opposite side of the
bridge to pass.
A bridge connects two networks together and allows communications
between the networks without the worry of distance violations or timing
considerations between the two networks. Each individual network must
be within maximum distance and timing specifications however. The
bridge is considered to be a node on the network and stores and forwards
packets on each network. Contrasted with a repeater that repeats the
signal bit by bit from one side of the network to the other, the bridge
actually reads each packet, checks the packet for accuracy, then makes a
decision, based on the destination address, as to whether the packet
should be sent to the other network. If the other network is busy, it is the
bridge's responsibility to store the packet, for a reasonable time, until the
transmission can be made.
It is also the responsibility of the bridge to handle collisions. If a collision
happens as the bridge is transmitting onto the second network, the bridge
is responsible for the back off and retransmission process. The original
sending node is not made aware of the collision. It assumes the packet has
been sent correctly. If for some reason the bridge is unable to send the
packet to its final destination, the original sending station, expecting a
response from the device it was attempting to contact, will "time out" and,
depending on the protocol, attempt retransmission.
The bridge makes decisions on whether to forward or filter a packet based
on the physical location of the destination device with respect to the
source device. Bridges dynamically learn the physical location of devices
by logging the source addresses of each packet and the bridge port the
packet was received on in a table called the Source Address Table (SAT).

ETHERNET BRIDGING
BRIM-E6 USER’S GUIDE Page 5
As with repeaters, IEEE recommends a maximum number of bridges that
can be in a signal path. With repeaters we are able to have a signal path of
4 repeaters, 5 segments. With bridges we can have a signal path of 7
bridges, 8 networks. The bridge count includes both local and remote
bridges.
Spanning Tree Algorithm
Since bridges play a very important role in the transfer of data from one
network to another, a helpful feature would be the ability to set up a
redundant bridge that would commence operation automatically if the
primary bridge failed. In the IEEE draft standard 802.1d, IEEE chose to
build some fault tolerance into the bridge specification. The 802.1d
specification defines bridge operation, redundancy and a process called
Spanning Tree Algorithm (STA). STA manages the primary and backup
bridges and also guards against data loops and duplicate data.
When a bridge is powered up, it goes through a series of self tests to
check its internal operation. During this time the bridge is in a standby, or
blocking condition and will not forward traffic. Also during this standby
period, the bridge sends out special bridge management packets called
Configuration Bridge Protocol Data Units (BPDU). A BPDU is 1 byte in
length and serves to identify the BPDU type as either a configuration or
topology change BPDU. Bridges use the BPDU packets as a way of
communicating with each other.
Spanning Tree Operation
Upon power up, Bridge 1 and 2 enter a standby, or blocking condition.
Bridge 2 transmits a Configuration BPDU from its root port claiming it is
the root. The BPDU is seen by Bridge 1 which inspects the BPDU for
address and priority along with other pertinent information. Assuming
equal priorities, Bridge 1 will transmit a BPDU to inform Bridge 2 of
Bridge 1's address and priority. Upon seeing the response from Bridge 1,
Bridge 2 determines that Bridge 1 has the higher priority and is therefore
the primary (or Root) bridge. Bridge 2 will remain in a standby or
blocking condition and will continue to monitor the network, listening for
Bridge 1 Configuration BPDUs. Once Bridge 1 is sure there are no data
loops, Bridge 1 comes on-line and normal network operations will
resume. This process is called spanning.

CHAPTER 1: INTRODUCTION
Page 6 BRIM-E6 USER’S GUIDE
If Bridge 2 fails to receive the Bridge 1 BPDUs during the period defined
by "Hello Time", Bridge 2 will initiate a re-span by transmitting a
topology change BPDU and eventually come on line to carry the network
load.
Bridges using STA can be utilized to create very fault tolerant networks.
This section has presented only basic information about bridges and
Spanning Tree Algorithm. For additional information, refer to the IEEE
802.1d draft specification.
1.7 RELATED MANUALS
Use the following manuals to supplement the procedures, and other
technical data provided in this manual.This manual references procedures
in these manuals, where appropriate, but does not repeat them.
Cabletron Systems’
EMM-E6 Installation Guide
Cabletron Systems’ EMM-E6 Local Management Guide
Cabletron Systems’ ESXMIM Installation Guide
Cabletron Systems’ ESXMIM Local Management Guide
Cabletron Systems’ MicroMMAC User’s Guide
Cabletron Systems’ NBR-620/420/220 Installation Guide
Cabletron Systems’ NBR-620/420/220 Local Management Guide

BRIM-E6 USER’S GUIDE Page 7
CHAPTER 2
INSTALLATION
This chapter contains instructions for installing your BRIM-E6 into a
Media Interface Module (MIM) or stand-alone product. It also explains
how to install an EPIM into the BRIM-E6.
Caution: Observe all static precautions while handling MIMs and EPIMs.
2.1 UNPACKING THE BRIM
Unpack the BRIM as follows:
1) Remove the shipping box material covering the BRIM.
2) Carefully remove the module from the shipping box. Leave the
module in its non-conductive bag until you are ready to install.
3) After removing the module from its non-conductive bag, visually
inspect the device. If you notice any signs of damage, contact
Cabletron Systems Technical Support immediately.
2.2 INSTALLING BRIMs
This section contains procedures on how to install a BRIM to upgrade or
change the capabilities of your mother board. To install your BRIM, you
need the following tools:
• 1 disposable static wrist strap (provided with any MIM or hub)
• 2 support post screws (included in your BRIM package)
• 1 Phillips screwdriver.
You can install a BRIM in any Cabletron product that supports BRIM
technology (e.g., EMM-E6, MicroMMAC, etc.). The following
subsections provide generic instructions for installing a BRIM in a MIM
or in a stand-alone product. Refer to your specific MIM or hub
documentation for exact BRIM slot and connector locations.

CHAPTER 2: INSTALLATION
Page 8 BRIM-E6 USER’S GUIDE
2.2.1 Installing a BRIM-E6 in a MIM
To install a BRIM-E6 in a MIM that supports BRIM technology (e.g.,
EMM-E6 or ESXMIM):
Note: We recommend that you power-down your hub even though
Cabletron MIMs have “hot swap” capabilities.
1. Power-down your MMAC hub.
2. Disconnect all cables from the MIM. Note the ports to which these
cables attach.
3. Unscrew the top and bottom knurled knobs of the MIM face plate.
4. Slide out the MIM, and place it on its side with the internal
components facing up.
5. Remove the BRIM coverplate screws and the BRIM coverplate.
(See Figure 2-1.)
Figure 2-1. Removing the Coverplate
Coverplate
Standoff

INSTALLING BRIMs
BRIM-E6 USER’S GUIDE Page 9
6. Place your BRIM behind the MIM face plate. (See Figure 2-2.)
Figure 2-2. Installing the BRIM
7. Insert the connector pins of the BRIM-E6 into the mother board
connector on the MIM.
8. Press down firmly on the back of the BRIM until the pins slide all
the way into the connector holes.
Note: The BRIM-E6 connector must fit securely on the mother board
connector.
9. Reinstall the faceplate mounting screws, and install the support
post screws.
Note: Faceplate and support post screws are provided both on the MIM
and in the BRIM package, for your convenience.
STB
CLN
BRIM-E6
XMT
RCV
EPIM-T
LNK

CHAPTER 2: INSTALLATION
Page 10 BRIM-E6 USER’S GUIDE
2.2.2 Installing a BRIM in a Hub
To install a BRIM-E6 into a stand-alone hub that supports BRIM
technology (e.g., MicroMMAC or NBR-620):
1. Power-down your hub.
2. Disconnect all cables from the hub. Note the ports to which these
cables attach.
3. Remove the hub chassis cover.
Note: Refer to your specific hub documentation for instructions on
removing the hub chassis cover.
4. Remove the BRIM coverplate screws and the BRIM coverplate.
(See Figure 2-1.)
5. Place your BRIM behind the hub face plate. (See Figure 2-2.)
6. Insert the connector pins of the BRIM into the mother board
connector in the hub.
7. Press down firmly on the back of the BRIM until the pins slide all
the way into the connector holes.
Note: The BRIM-E6 connector must fit securely on the mother board
connector.
8. Reinstall the faceplate mounting screws, and install the support
post screws.
9. Reattach the chassis cover to the hub and reconnect the hub to your
network.
Note: Faceplate and support post screws are provided both on the hub
and in the BRIM package, for your convenience.

INSTALLING BRIMs
BRIM-E6 USER’S GUIDE Page 11
2.2.3 Installing an EPIM into the BRIM
To install an EPIM into the BRIM:
1. Slide the EPIM into the BRIM slot. See Figure 2-3.
Figure 2-3. Installing an EPIM into the BRIM-E6
2. Press the EPIM connector firmly into the connector on the BRIM.
3. Tighten the EPIM screw.
BRIM-E6
STB
RCV
CLN
XMT

BRIM-E6 USER’S GUIDE Page 13
CHAPTER 3
CONNECTINGTOTHE NETWORK
This chapter outlines the procedure for connecting the BRIM-E6 to a
network.
3.1 CONNECTING THE BRIM TO THE NETWORK
The procedure for connecting network segments to the BRIM-E6 depends
on which EPIM you install. Refer to the following list and perform the
procedure described in the subsections that apply to your configuration:
• EPIM-T 3.1.1
• EPIM-F1, F2, F3 3.1.2
• EPIM-C 3.1.3
• EPIM-A 3.1.4
• EPIM-X 3.1.5
Prior to connecting the network cabling check the connectors for the
proper pinouts as shown in AppendixA.
3.1.1 Connecting a UTP Segment to an EPIM-T
Before connecting a segment to the EPIM-T, check each end of the
segment to determine if the wires have been crossed-over for the proper
connection. If the wires do not cross over, use the switch on the EPIM-T
to internally cross over the RJ45 port. Refer to Figure 3-1 to properly set
the EPIM-T cross-over switch.

CHAPTER 3: CONNECTING TO THE NETWORK
Page 14 BRIM-E6 USER’S GUIDE
Figure 3-1. EPIM-T Cross-over Switch
To connect an EPIM-T to a Twisted Pair Segment:
1. Insert the RJ45 connector on the twisted pair segment into the RJ45
port on the EPIM. See Figure 3-1.
2. Check that the EPIM’s LNK LED is on. If the LED is not on, perform
each of the following steps until it is:
a. Checkthatthe10BASE-Tdeviceat theotherend ofthetwisted
pair segment is powered up.
b. Verifythat theRJ45 connectoron thetwisted pairsegment has
the proper pinouts.
c. Check the cable for continuity.
d. Check that the twisted pair connection meets dB loss and cable
specifications outlined in Appendix B.
e. Check that the crossover switch is in the correct position.
If a link still has not been established, contact Cabletron Systems
Technical Support.
Position =
(not crossed over)
1. TX+
2. TX-
3. RX+
4. NC
5. NC
6. RX-
7. NC
8. NC
Position X
(crossed over)
1. RX+
2. RX-
3. TX+
4. NC
5. NC
6. TX-
7. NC
8. NC