Cabletron Systems IRM-3 User Manual

IRM3

INTELLIGENT REPEATER

MODULE

USER’S GUIDE

IRM3

SN

RESET

PWR BOK

MGMT

CLN

PWRON

ON LNK

T
X

R
X

RCV
POK

A
U
I

F

O

I

R

L

ETHERNET

U
P
S

C
O
N
S
O
L
E

IRM3 QUICK REFERENCE CARD

LED INDICATORS

LED Description

PWR IRM3 is receiving power from MMAC.
BOK LED lit-Board is operating properly.

LED not lit-Initialization problem. Press
Reset switch.

RCV IRM3 is repeating packet received from a

connected segment.

MGMT IRM3 is receiving/transmitting management

packets.
CLN Collision detected on a segment.
POK Internal repeater port is OK.
ON (AUI) AUI port is active repeater port.
PWR (AUI) AUI port is receiving power.
ON (FO) Fiber Optic port is active repeater port.
LNK (FO) Link is established between port and Fiber

Optic device.

CONNECTIONS

IRM3

SN

RESET

PWR BOK

MGMT RCV

CLN POK

ON PWR

A
U

ON LNK

T
X

F
O

I

AUI Port: 15-pin D type receptacle

Pin Signal Pin Signal Pin Signal

1 Logic Ref 6 Power Return 11 Logic Ref
2 Collision+ 7 No Connection 12 Receive­3 Transmit+ 8 Logic Ref 13 Power (+12Vdc)
4 Logic Ref 9 Collision- 14 Logic Ref
5 Receive+ 10 Transmit- 15 No Connection

Console/Modem Port: Standard 9-pin RS232 port

Pin Signal Pin Signal

1 Carrier Detect (CD) 6 Receive Clock (RXCL)
2 Transmit (TXD) 7 Request to Send (RTS)
3 Receive (RXD) 8 Clear to Send (CTS)
4 Data Terminal Ready (DTR) 9 Ring Indicator (RI)
5 Logic Ref

IRM3 User’s Guide Part of 9030494 -01

IRM3 QUICK REFERENCE CARD

JUMPER SETTINGS

Jumper Function Setting Default

H1 Enables/Disables Battery.

When enabled, user-entered
parameters are saved if power
to the IRM3 fails. When
disabled, parameters are lost.

JP1 Makes IRM3 compatible with

any THN-MIMs being used in
the MMAC. This jumper is set
for THN-MIMs with part
numbers 9000043-06 and
above and for THN-MIMs with
part numbers below
9000043-06.

H6
and H8

Sets IRM3 console and modem
ports for either internal (signal
generated by IRM3) or external
(signal generated by attached
device) Request to Send (RTS)
and Clear to Send (CTS)
signals.

Enable: Jumper over pins
1 and 2

Disable: Jumper over pins
2 and 3

9000043-06 and up:
Jumper over pins 2 and 3

Below 9000043-06:
Jumper over pins 1 and 2

If using both, set over 1
and 2

Internal: Jumper over pins
1 and 2

External: Jumper over
pins 2 and 3

Disable

Jumper
over pins 2
and 3

External

Battery
Enable/Disable

THN-MIM Jumper

H1/JP1
Pin Numbers

JP1

H1

For Cabletron Use Only

H4

H5

CTS-Modem Port

CTS-Console Port

1
2
3

H6/H8
Pin Numbers

1 2 3

H2

H3

H8

H6

0494104

Part of 9030494-01 IRM3 User’s Guide

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 BEEN
ADVISED OF, KNOWN, OR SHOULD HAVE KNOWN, THE POSSIBILITY OF SUCH
DAMAGES.



Copyright 1996 by Cabletron Systems, Inc., P.O. Box 5005, Rochester, NH 03866-5005
All Rights Reserved
Printed in the United States of America

Order Number: 9030494-01 January 1996

SPECTRUM, LANVIEW, MicroMMAC
Manager, EPIM, EPIM-A, EPIM-F1, EPIM-F2, EPIM-F3, EPIM-T, EPIM-X, FOT-F, FOT-F3
HubSTACK, IRM3, SEH, SEHI

All other product names mentioned in this manual may be trademarks or registered trademarks of
their respective companies.

, and

, and

TMS-3

BRIM

are trademarks of Cabletron Systems, Inc.

are registered trademarks and

Element

,

IRM3 User’s Guide i

Printed on Recycled Paper

Notice

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:

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:

party responsible for compliance could void the user’s authority to operate the equipment.

This equipment has been tested and found to comply with the limits for a Class A digital

Changes or modifications made to this device which are not expressly approved by the

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.

VCCI NOTICE

This equipment is in the 1st Class Category (information equipment to be used in commercial and/or
industrial areas) and conforms to the standards set by the Voluntary Control Council for Interference
by Information Technology Equipment (VCCI) aimed at preventing radio interference in commercial
and/or industrial areas.

Consequently , when used in a residential area or in an adjacent area thereto, radio interference may be
caused to radios and TV receivers, etc.

Read the instructions for correct handling.

ii IRM3 User’s Guide

Notice

CABLETRON SYSTEMS, INC. PROGRAM LICENSE AGREEMENT

IMPORTANT:

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 LICENSE AND
THE LIMITATION OF WARRANTY AND DISCLAIMER OF LIABILITY. IF YOU DO NOT
AGREE TO THE TERMS OF THIS AGREEMENT , PR OMPTLY RETURN THE UNUSED
PRODUCT TO THE PLACE OF PURCHASE FOR A FULL REFUND.

Before utilizing this product, carefully read this License Agreement.

CABLETRON SOFTWARE PROGRAM LICENSE

1. LICENSE

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 LA W. 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.

. You have the right to use only the one (1) copy of the Program provided in this

EXCLUSION OF WARRANTY AND DISCLAIMER OF LIABILITY

1. EXCLUSION OF

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 EXPRESSED OR IMPLIED, INCLUDING
BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE, WITH RESPECT TO THE PROGRAM, THE
ACCOMPANYING WRITTEN MATERIALS, AND ANY A CCOMPANYING HARDWARE.

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 WARRANTIES, IN SOME
INSTANCES THE ABOVE LIMITATIONS AND EXCLUSIONS MAY NOT APPLY TO
YOU.

WARRANTY. Except as may be specifically provided by Cabletron in

IRM3 User’s Guide iii

Notice

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 03867-0505.

iv IRM3 User’s Guide

CONTENTS

CHAPTER 1 INTRODUCTION

1.1 Using This Manual.......................................................................1-1

1.2 The Intelligent Repeater Module (IRM3) .....................................1-2

1.3 IRM3 Front Panel ........................................................................1-4

1.3.1 IRM3 Features................................................................1-5

1.4 Repeater Functionality.................................................................1-5

1.5 Network Management Capabilities..............................................1-6

1.6 Getting Help.................................................................................1-7

1.7 Document Conventions............................................................... 1-8

1.8 Related Manuals..........................................................................1-9

CHAPTER 2 NETWORK PLANNING AND CONFIGURATION

2.1 Network Requirements................................................................2-1

2.1.1 802.3 Repeater Requirements........................................ 2-1

2.1.2 AUI Port Requirements................................................... 2-1

2.1.3 Fiber Optic Port Requirements .......................................2-2

2.2 The IRM3 in the Multi Media Access Center...............................2-3

2.2.1 Media Interface Modules ................................................2-4

2.3 Sample Network Configuration....................................................2-5

CHAPTER 3 INSTALLING THE IRM3

3.1 Unpacking the IRM3....................................................................3-1

3.2 Setting the IRM3 Jumpers...........................................................3-2

3.2.1 Setting the Battery Enable/Disable Jumper (H1)............3-2

3.2.2 Setting the CTS External/Internal Jumper (H6, H8)........ 3-3

3.2.3 Setting the THN-MIM Jumper (JP1)................................3-4

3.3 Installing the IRM3 into an MMAC Chassis.................................3-4

3.4 Pre-installation Test.....................................................................3-7

3.5 Connecting the IRM3 to the Network...........................................3-8

3.5.1 Connecting to the Network Through the AUI Port ..........3-9

3.5.2 Connecting to the Network Through the
Fiber Optic Port3-10

3.6 Installation Checkout................................................................. 3-12

3.7 Connecting to the UPS Through the Console Port....................3-13

IRM3 User’s Guide v

Contents

CHAPTER 4 LOCAL MANAGEMENT

4.1 Accessing Local Management Using a Terminal.........................4-3

4.1.1 Configuring a Local Management Terminal ....................4-3

4.1.2 Terminal Attachment Cable Configuration ......................4-4

4.1.3 Connecting the Terminal and Accessing Local
Management4-5

4.2 Accessing Local Management Using a Modem...........................4-7

4.2.1 Modem Configurations....................................................4-7

4.2.2 Modem Attachment Cable Configuration ........................4-7

4.2.3 Connecting the Modem and Accessing Management.....4-8

4.3 The Password Screen..................................................................4-9

4.4 The Device/Board/Port Counters Screen...................................4-10

4.4.1 Configuring the Device/Board/Port Counters Screen....4-11

4.4.2 Device/Board/Port/Counters Screen Fields...................4-12

4.4.3 Resetting the Device/Board/Port Counters ...................4-13

4.4.4 Using the Enable Board/Disable Board Options ...........4-14

4.4.5 Using the Enable Port/Disable Port Option...................4-14

4.4.6 Available Options from the Device/Board/Port Counters
Screen4-14

4.5 Community Names Screen........................................................4-15

4.5.1 Accessing the Community Names Screen....................4-16

4.5.2 Community Names Screen Fields.................................4-16

4.5.3 Editing the Community Names Screen .........................4-17

4.6 The Setup Screen......................................................................4-18

4.6.1 Accessing the Setup Screen.........................................4-19

4.6.2 Setup Screen Fields......................................................4-19

4.6.3 Setting the Set IP Address Option.................................4-20

4.6.4 Setting the Set Current Date Option..............................4-21

4.6.5 Setting the Set Current Time Option.............................4-21

4.6.6 Setting the Device Lock Option.....................................4-21

4.6.7 Setting the Set Refresh Time Option.............................4-22

4.7 Port Association Screen.............................................................4-22

4.7.1 Accessing the Port Association Option .........................4-22

4.7.2 Port Association Screen Fields .....................................4-23

4.7.3 Changing the Port Association......................................4-24

4.8 The Token Ring Board Status Screen.......................................4-24

4.8.1 Accessing the Token Ring Board Status Screen ..........4-25

4.8.2 Token Ring Board Status Screen Fields.......................4-26

4.8.3 Editing the Token Ring Board Status Screen................4-29

vi IRM3 User’s Guide

Contents

CHAPTER 5 TROUBLESHOOTING

5.1 Using LANVIEW..........................................................................5-1

5.2 Troubleshooting Checklist...........................................................5-4

5.3 Using the Reset Switch ...............................................................5-5

5.4 Before Calling Technical Support................................................5-5

APPENDIX A SPECIFICATIONS

A.1 Repeater Functionality.................................................................A-1

A.2 AUI Port.......................................................................................A-2

A.3 Fiber Optic Interface....................................................................A-2

A.4 Console Port................................................................................A-3

A.5 Microprocessors and Memory.....................................................A-3

A.6 Environmental Requirements......................................................A-3

A.7 Agency Approvals........................................................................A-4

A.8 Service.........................................................................................A-4

A.9 Physical Properties......................................................................A-4

INDEX

IRM3 User’s Guide vii

CHAPTER 1

INTRODUCTION

Welcome to the Cabletron Systems

(IRM3) User’s Guide

management, and reference guide for the IRM3, and includes a
description of the IRM3 capabilities and special features. The IRM3
provides a high performance IEEE 802.3 repeater with sophisticated
network management capabilities for use in a Cabletron Systems Multi
Media Access Center (MMAC).

. This manual serves as an installation,

Intelligent Repeater Module

1.1 USING THIS MANUAL

Before installing and operating the IRM3, read through this guide to gain
a full understanding of its capabilities.

It is assumed that you have a general working knowledge of Ethernet or
IEEE 802.3 type data communications networks and their physical layer
components.

This guide is organized as follows:
Chapter 1,

including an explanation of the IRM3 repeater functionality and its
management capabilities. This chapter concludes with instructions on
how to get help if needed and a list of related manuals.

Chapter 2,
configuration requirements to consider before installing the IRM3. This
chapter also includes a sample configuration for the IRM3.

Chapter 3,
IRM3 into an MMAC. This chapter also includes instructions for
connecting the IRM3 to the network.

Introduction

Network Planning and Configuration

Installing the IRM3

, describes the capabilities of the IRM3,

, contains instructions for installing the

, provides

IRM3 User’s Guide Page 1-1

Chapter 1:

Introduction

Chapter 4,

Local Management

, describes Local Management (LM) and
control capabilities for the IRM3. Local Management provides the tools
to manage the IRM3 and its attached segments.

Chapter 5,

Troubleshooting,

details the LANVIEW LEDs incorporated
into the IRM3, which enable you to quickly diagnose any problems that
may occur with the IRM3. This chapter also includes a troubleshooting
checklist, procedures for using the reset switch and instructions for
calling technical support.

Appendix A,

Specifications

, contains location requirements and

operating specifications for the IRM3.

1.2 THE INTELLIGENT REPEATER MODULE (IRM3)

The Intelligent Repeater Module (IRM3) (Figure 1-1) is the heart of the
Cabletron Systems Multi Media Access Center (MMAC). The IRM3
incorporates a high performance IEEE 802.3 repeater to allow maximum
data paths between devices connected to the MMAC.

The IRM3 is Simple Network Management Protocol (SNMP) compliant,
and can be controlled and monitored by a variety of SNMP Network
Management packages. These include Cabletron Systems SPECTRUM
Element Manager for Windows, Cabletron Systems SPECTRUM, and
third party SNMP network management packages. Additionally, the
IRM3 can be controlled and monitored by IRM3/LM - Local
Management for the IRM3 through a terminal connected locally or
through a Hayes compatible modem.

Page 1-2 IRM3 User’s Guide

The Intelligent Repeater Module (IRM3)

.

IRM3

SN

RESET

PWR BOK

MGMT

CLN

RCV
POK

PWRON

A
U
I

ON LNK

T
X

R

O
R

X

ETHERNET

F

I

L

U
P
S

C
O
N
S
O
L
E

Figure 1-1 Intelligent Repeater Module (IRM3)

IRM3 User’s Guide Page 1-3

0494101

Chapter 1:

Introduction

1.3 IRM3 FRONT PANEL

The IRM3 incorporates two ports that connect to external network
segments:

• One pair of IEEE 802.3 FOIRL fiber optic ports. The fiber optic ST

port accommodates a wide variety of multimode fiber optic cable,

µ

including 50/125
up to 2 km in length.

• An IEEE 802.3 compliant AUI port. The AUI port allows you to

connect the module to a variety of Ethernet transmission media
including twisted pair, fiber optic, and/or thick or thin Ethernet coaxial
cable by way of an external transceiver.

Either one of these ports can act as the repeater port to the external
network. When the IRM3 is first powered up, the AUI port acts as the
repeater port and the fiber ports are off. Using the IRM3 network
management capabilities (see Chapter 4,
reverse this configuration to ha ve the fiber port act as the repeater port and
have the AUI port off. This configuration allows you to connect the IRM3
to a fiber optic link segment directly without having to use an external
fiber optic transceiver.

m, 62.5/125 µm, and 100/140 µm fiber optic cable,

Local Management

), you can

The IRM3 also provides the option, through remote management, to set
one port as the active repeater port and the other port as a redundant
repeater port.

Built into the front panel of the IRM3 are two standard 9-pin RS232
console ports labeled CONSOLE and UPS. The CONSOLE port enables
you to access the IRM3/LM locally or remotely using a Hayes compatible
modem. If you are using a CS-600R/CS-1250R series Uninterruptible
Power Source (UPS), the UPS port enables you to monitor and control the
UPS through the IRM3 using SPECTRUM Element Manager for
Windows or SPECTRUM. The front panel also has a reset switch to
initialize the IRM3 processor.

The IRM3 incorporates the Cabletron Systems LANVIEW Status
Monitoring and Diagnostic System. If a problem arises, such as a power
failure or a cable fault, the LANVIEW LEDs (see Section 5.1,

LANVIEW

) help you to diagnose it.

Using

Page 1-4 IRM3 User’s Guide

Repeater Functionality

The LANVIEW LEDs on the IRM3 indicate the following conditions:

• The IRM3 is receiving power

• An error has been detected with the IRM3

• The IRM3 is receiving packets from any segment connected to the
MMAC

• The IRM3 is detecting a collision from the network

1.3.1 IRM3 Features

There are a number of features that provide for efficient use and
maintenance of the IRM3. These features include the following:

• Flash EPROM. This feature enables you to upgrade the IRM3 without
replacing firmware. Flash EPROMs can be updated remotely by
downloading the new software by way of Cabletron Systems
SPECTRUM Element Manager for Windows.

• Thermal Sensors. These sensors warn the management station if the
IRM3 begins to overheat.

• Ethernet SNMP Proxy. With SNMP proxy , you can use IRM3 remote
management to control power settings for the American Power
Conversion’s uninterruptible power source (UPS).

• Connect the UPS to the IRM3 UPS port to control the power supply
through an SNMP compliant network management tool, such as
Cabletron Systems SPECTRUM Element Manager for Windows and
SPECTRUM.

1.4 REPEATER FUNCTIONALITY

The IEEE 802.3 compliant repeater on the IRM3 provides the MMAC
with the ability to achieve maximum data paths on all Ethernet
transmission media, including 10BASE-T, fiber optic, and thick or thin
Ethernet type cabling. To attain maximum data paths, the IRM3 retimes

IRM3 User’s Guide Page 1-5

Chapter 1:

Introduction

data packets and regenerates the preamble of each data packet that enters
the MMAC.

In addition, IRM3 repeater functionality assures that problem segments
connected to any port on the MMAC do not affect any other segments
connected to the MMAC. If 32 consecutive collisions are detected on any
segment, or if a collision detector is on for more than 2.4 ms, the IRM3
automatically partitions that segment. The segment automatically
reconnects to the MMAC after a packet is transmitted onto the segment
without causing a collision.

1.5 NETWORK MANAGEMENT CAPABILITIES

The Cabletron Systems IRM3 can be controlled and managed by a variety
of network management packages which include the following:

• Cabletron Systems SPECTRUM

• Cabletron Systems SPECTRUM Element Manager for Windows

• Cabletron Systems IRM3/LM (Local Management)

• Third Party SNMP compliant Network Management Packages
The IRM3 network management capabilities provide the necessary

management tools for the IRM3 to operate at its full capacity . Your ability
to set up parameters within the network management capabilities ensures
optimal performance of the IRM3, and, hence, the network.

For example, a great deal of statistical information on the port, board, and
MMAC device level is gathered by the IRM3, including each of the
following:

• Packets • Bytes Received

• Collisions • Giant Packets

• Runt Packets • Misaligned Packets

• Frame Size • Out of Window Collisions

• Breakdowns • CRC Errors

Page 1-6 IRM3 User’s Guide

Getting Help

To help you see how your network is being used, and to help you plan for
future network use, the IRM3 also provides Ethernet protocol counters on
the port and board level for the following protocols:

• AppleTalk

• Banyan

• Cabletron

• DECnet

• ISO/OSI

• Novell

• TCP/IP

• XNS

• Other

For further specific information on in-band management of the IRM3,
refer to the applicable Network Management Package User’s Manual.

1.6 GETTING HELP

If you need additional support related to the IRM3, or if you have any
questions, comments, or suggestions related to this manual, contact
Cabletron Systems Technical Support:

By phone [phone]

8 P.M. Eastern time

Monday–Friday, 8
By CompuServe GO CTRON from any ! prompt
By Internet mail: [e-mail]
By FTP ctron.com (134.141.197.25)

Login:

Password:

anonymous

your email address

A.M –

IRM3 User’s Guide Page 1-7

Chapter 1:

Introduction

Before calling Cabletron Systems Technical Support, be prepared to
provide the following information:

• A detailed description of the failure.

• A description of any action already taken to resolve the problem
(swapping the bad unit with a unit known to work properly, etc.)

• A description of your network (environment, layout, cable type and
length, etc.)

• Serial numbers of all Cabletron Systems products used in the network.

• Revision level of all Cabletron Systems products in the network

• Revision level of firmware installed on all Cabletron Systems products

• The network load and frame size at the time of the failure, if known

• Product history (had the product been returned previously, did it have
the same problem, etc.)

• The RMA number generated, if any

1.7 DOCUMENT CONVENTIONS

The following conventions are used throughout this document:

NOTE

TIP

NOTE

information that may be of special importance.

TIP

actions.

symbol. Calls the reader’s attention to any item of

symbol. Conveys helpful hints concerning procedures or

CAUTION

!

CAUTION

WARNING

Page 1-8 IRM3 User’s Guide

damage to the equipment.

WARNING

equipment damage, personal injury or death.

symbol. Contains information essential to avoid

symbol. Warns against an action that could result in

Related Manuals

1.8 RELATED MANUALS

The manuals listed below should be used to supplement the procedures
and other technical data provided in this manual. The procedures will be
referenced where appropriate, but will not be repeated.

Cabletron Systems

Guide.

Multi Media Access Center Overview and Setup

Cabletron Systems

Windows.

IRM3 Management Module Guide for Microsoft

IRM3 User’s Guide Page 1-9

CHAPTER 2

NETWORK PLANNING AND CONFIGURATION

This chapter addresses some of the configuration issues that you should
consider when installing the IRM3, including 802.3 standards related to
repeaters, transceivers, and cables. This chapter also gives an overview of
Cabletron Systems Multi Media Access Center (MMAC) and the Media
Interface Modules (MIM) that can be managed by the IRM3. Finally, an
example of a network configuration using the IRM3 is provided.

2.1 NETWORK REQUIREMENTS

When connecting network segments to the IRM3, you must follow the
network guidelines listed below.

2.1.1 802.3 Repeater Requirements

Depending on the size of your network, you may need to use multiple
repeaters. When planning your network, keep in mind that 802.3
standards allow for no more than four repeaters in one data path. If your
network requires more than four repeaters, use a bridge to create a new
data path.

2.1.2 AUI Port Requirements

The IRM3 provides the flexibility of connecting to a network with
different types of media through the AUI port. Using an AUI cable along
with the proper Cabletron Systems transceiver, you can connect to the
network with AUI cable, coaxial cable, twisted pair cable, or fiber optic
cable.

IRM3 User’s Guide Page 2-1

Chapter 2: Network Planning and Configuration

When connecting a network segment to the IRM3 through a transceiver
and an AUI cable, the following requirements must be met:

• The transceiver to which the IRM3 will be connected must meet
Ethernet Version 1, Version 2 or IEEE 802.3 standards.

• The A UI cables connecting the IRM3 to the transceiver on the netw ork
must be IEEE 802.3 type cables and must not exceed 50 meters in
length.

• The Signal Quality Error (SQE) function on the transceiver must be
disabled.

The SQE function is used to confirm that the collision signaling

NOTE

of the transceiver is working properly. However, when
connecting a transceiver to the IRM3, or any other repeater,
you must disable the SQE test function. If SQE is not disabled,
the repeater regards each SQE signal as a collision and
resends the JAM packet, causing a considerable slowdown of
network operations.

2.1.3 Fiber Optic Port Requirements

When connecting a Fiber Optic Link Segment to the IRM3 fiber optic ST
ports, the following requirements must be met:

• Cable Type - The fiber optic link segment should consist of one of the
following:

- 50/125 µm fiber optic cabling

- 62.5/125 µm fiber optic cabling

- 100/140 µm fiber optic cabling

• 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:

- 13.0 dB or less for 50/125 µm fiber cable segment

- 16.0 dB or less for 62.5/125 µm fiber cable segment

- 19.0 dB or less for 100/140 µm fiber cable segment

Page 2-2 IRM3 User’s Guide

The IRM3 in the Multi Media Access Center

• 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 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 a packet to travel from the sending device to
the receiving device.

• Length - IEEE 802.3 specifications for fiber optic cable allow for a

maximum of 1 km. Howe ver , distances of at least 2 km can usually be
achieved.

2.2 THE IRM3 IN THE MULTI MEDIA ACCESS CENTER

The IRM3 is designed to be installed in a Cabletron Systems Multi Media
Access Center (MMAC) network hub with the Flexible Network Bus
(FNB) - See Figure 2-1. The MMAC is fully protocol independent and is
available in an eight slot (MMAC-M8FNB), five slot (MMAC-M5FNB)
and three slot (MMAC-M3FNB) model.

When installed in an MMAC, the IRM3 supports 10 Mbps Ethernet
(IEEE 802.3), as well as 4 and 16 Mbps Token Ring (IEEE 802.5) Media
Interface Modules (MIMs) using shielded twisted pair (STP) or
unshielded twisted pair (UTP), fiber optic, thin or thick coaxial and
standard AUI transceiver cabling. The IRM3 retimes and regenerates
packets for each port of each Ethernet MIM installed in the MMAC, and
allows users to access management information for all Token Ring and
Ethernet MIMs in the MMAC.

Power & Management Bus

Ethernet A Bus

Flexible Network Bus

Ethernet B Bus

Ethernet C Bus

IRM3 User’s Guide Page 2-3

0494102

Figure 2-1 MMAC with FNB

Chapter 2: Network Planning and Configuration

2.2.1 Media Interface Modules

The following is a description of the types of Cabletron Systems MIMs
that can be installed in the MMAC and managed by the IRM3.

THN-MIM Thin Coaxial Module

The THN-MIM has 12 Ethernet/IEEE 802.3 compliant attachments to
either thin or thick coaxial cable through a thick-to-thin adapter. The thin
coaxial segment, which may be up to 185 meters in length, can
accommodate up to 29 connections per segment. The thick coaxial
segment may extend to 500 meters in length and provide up to 99
connections.

MT8-MIM Multiport Transceiver Interface Module

The MT8-MIM provides eight separate transceivers in one unit that can
be inserted into the MMAC. The MT8-MIM provides eight IEEE

802.3-compatible medium attachment unit (MAU) ports, which allows a

direct connection to any type of media.

TPMIM 10BASE-T Modules

Cabletron Systems TPMIM 10BASE-T modules are available with 12 or
24 ports equipped with DB9, RJ45, or RJ71 connectors for
shielded/unshielded twisted pair connections of up to 125 meters in
length.

FOMIM Fiber Optic Modules

Cabletron Systems FOMIM fiber optic modules are available with 6, 12
or 18 ports equipped with either ST (straight tip) or SMA (subminiature
type A) connectors, with models that support either single mode or
multimode cable. The FOMIMs provide Ethernet/IEEE 802.3 Fiber Optic
Inter Repeater Link (FOIRL) compatible attachments over 50, 62.5 or 100
µm core multimode fiber cabling, or 8/125 - 12/125 µm core single mode
cabling. Each port of the multimode modules can drive fiber optic link
segments up to 2 km in length. Each port on the single mode modules can
drive fiber segments up to 10 km, provided that system budgets are met.

Page 2-4 IRM3 User’s Guide

Sample Network Configuration

TRMIM Token Ring Modules

Cabletron Systems TRMIM Token Ring modules are available with 12 or
24 ports equipped with either RJ45 or DB9 connectors. Token Ring
modules that support unshielded twisted pair (UTP) cable provide for
segments of up to 100 meters. With modules that support shielded twisted
pair (STP) cable, you can attach segments of up to 200 meters.

2.3 SAMPLE NETWORK CONFIGURATION

The following illustrates a simple network configuration that provides a
general idea of how the IRM3 can be used in a network. Each workstation
will have access to each other and the server through the TPMIM and the
IRM3. The IRM3 manages the backplane and repeating functions
between the users on the network. The TPMIM provides access to the
backplane for the workstations while the IRM3 repeats the incoming
traffic to the other stations on the network. Control of the boards and ports
is accessed through the IRM3 Local Management.

Workstations

MMAC3 with IRM3

Server

0494103

Figure 2-2 Example of a Small Network Configuration

IRM3 User’s Guide Page 2-5