Cabletron Systems IRM-2 Installation Manual

INTELLIGENT REPEATER MODULE

(IRM-2)

INSTALLATION GUIDE

CABLETRON SYSTEMS, P.O. Box 5005, Rochester, NH 03867-5005

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 June 1991 by:

Cabletron Systems Inc.
P.O. Box 6257, E. Rochester, NH 03867-6257

All Rights Reserved
Printed in the United States of America

Order number: 9030316-01 June 91

Remote LANVIEW/Windows, SPECTRUM, LANVIEW, IRM-2, IRM2/LM, MMAC-8,
MMAC-8FNB, MMAC-5FNB, MMAC-3, MMAC-3FNB, PSM, PSM-R, MMAC-5PSM
LAN-MD

are trademarks of Cabletron Systems Inc.

and

i

FCC NOTICE

FCC NOTICE

This device complies with Part 15 of FCC rules. Operation is subject to the follo wing two conditions:
(1) this device may not cause harmful interference, and (2) this device must accept any interference
received, including interference that may cause undesired operation.

WARNING

device, pursuant to Part 15 of FCC Rules. These limits are designed to pro vide 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 at his own expense to correct the interference.

If this equipment does cause interference to radio or television, which can be determined by turning
the equipment off and on, the user is encouraged to try to correct the interference by one or more of
the following measures:

• Re-orient the receiving antenna.

• Relocate the antenna with respect to the MMAC.

• Move the MMAC away from the antenna.

• Plug the MMAC into a different outlet so that the MMAC and the receiver are on different

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

branch circuits.

If necessary, the user should consult the dealer or an experienced radio/ television technician for
additional suggestions. The user may find the following booklet prepared by the Federal
Communication Commission helpful:

“How to Identify and Resolve Radio TV Interference Problems”

This booklet is available from the U.S. Government Printing Office, Washington D.C. 20402 - Stock
No. 004-000-00345-4

ii

CONTENTS

CHAPTER 1 INTRODUCTION

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

1.2 Getting Help.................................................................................1-2

1.3 The Intelligent Repeater Module (IRM-2)....................................1-2

1.4 Repeater Functionality.................................................................1-4

1.5 Network Management Capabilities..............................................1-4

1.6 Related Manuals..........................................................................1-5

CHAPTER 2 NETWORK REQUIREMENTS/SPECIFICATIONS

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

2.1.1 AUI Port Requirements.......................................................2-1

2.1.2 Fiber Optic Port Requirements...........................................2-1

2.2 Operating Specifications..............................................................2-2

CHAPTER 3 INSTALLING THE IRM-2

3.1 Unpacking the IRM-2...................................................................3-1

3.2 Setting the IRM-2 Jumpers..........................................................3-1

3.2.1 Setting the Battery Enable/Disable Jumper (H1)................3-1

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

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

3.3 Installing the IRM-2......................................................................3-3

3.4 Selecting the Repeater Port ........................................................3-5

3.5 Connecting the IRM-2 to the Network .........................................3-5

3.5.1 Connecting to the Network Via the AUI Port ......................3-5

3.5.2 Connecting to the Network Via the Fiber Optic Port...........3-8

CHAPTER 4 TESTING AND LANVIEW

4.1 Installation Check-Out.................................................................4-1

4.2 Using LANVIEW..........................................................................4-2

4.3 Using the Reset Switch ...............................................................4-4

iii

CONTENTS

iv

CHAPTER 1

INTRODUCTION

Welcome to the Cabletron Systems

(IRM-2™) Installation Guide

a simple installation and reference guide for the IRM-2, and to explain the
capabilities and special features of the IRM-2. The IRM-2 provides a high
performance IEEE 802.3 Repeater with sophisticated network
management capabilities for use in a Cabletron Systems Multi Media
Access Center (MMAC™).

You should read through this manual to gain a full understanding of the
IRM-2 and its capabilities.

Intelligent Repeater Module

. We have designed this manual to serve as

1.1 USING THIS MANUAL

Chapter 1,
IRM-2. The chapter includes an explanation of the IRM-2’s repeater
functionality and a discussion of the IRM-2’s Management capabilities.
The chapter concludes with a list of related manuals.

Chapter 2,
network requirements that must be met before you install the IRM-2. The
specifications for the IRM-2 are also included in this chapter.

Introduction

Installation Requirements/Specifications

, discusses the capabilities of Cabletron Systems’

, contains a list of

Chapter 3,
IRM-2 into the MMAC. The chapter also includes instructions for
connecting the IRM-2 to the network.

Chapter 4,
and troubleshooting the installation of the IRM-2. Instructions for using
LANVIEW™, Cabletron Systems’ built-in visual diagnostic and status
monitoring system, are also included.

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

Installing the IRM-2

Testing and Troubleshooting

, contains instructions for installing the

, provides procedures for testing

1-1

INTRODUCTION

1.2 GETTING HELP

If you need additional support related to the Cabletron Systems
IRM-2, or if you have any questions, comments or suggestions related to

this manual, feel free to contact Cabletron Systems’ Technical Support at:
Cabletron Systems Inc.

35 Industrial Way
P.O. Box 5005
Rochester, NH 03867-5005
Phone: [phone]

1.3 THE INTELLIGENT REPEATER MODULE (IRM-2)

The Cabletron Systems Intelligent Repeater Module (IRM-2) (Fig. 1-1) is
the heart of the Cabletron Systems Multi Media Access Center. The
IRM-2 incorporates a high performance IEEE 802.3 repeater to allow
maximum data paths between devices connected to the MMAC.

Since the IRM-2 is SNMP compliant, it can be controlled and monitored
by a variety of SNMP Network Management packages. These include
Cabletron Systems’ Remote LANVIEW/Windows, Cabletron Systems’
SPECTRUM, and third party SNMP network management packages.
Additionally , the IRM-2 can be controlled and monitored by IRM2/LM™

- Local Management for the IRM2 via a locally connected terminal.
The IRM-2 incorporates two ports that connect to external network

segments: one pair of IEEE 802.3 FOIRL fiber optic ports and an IEEE

802.3 compliant AUI port. The fiber optic ST ports can accommodate a

µ

wide variety of multi-mode fiber optic cable, including 50/125

µ

62.5/125

m, and 100/140 µm fiber optic cable, up to 3km in length. The

m,

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 via an external transceiver.

Either one of these ports can act as the repeater port to the external
network. When the IRM-2 is first powered up, the AUI port acts as the
repeater port and the fiber ports are off. Using the IRM-2

1-2

INTRODUCTION

IRM-2

SN

M
M
A
C

ERR
PWR

9 Pin RS232 Port

RCV1

RCV
XMT

CLN
POK

POK1

C
O
N
S
O
L
E

MMAC
LANVIEW LEDs

Front Panel Switches

15 Pin DB-15
AUI Port

RESET

LNK

T
X

R
X

ETHERNET

A
U

I

F
O

I
R
L

Reset Switch

Fiber Optic Ports
LANVIEW LEDs

Fiber Optic Ports

Figure 1-1 Intelligent Repeater Module (IRM-2)

1-3

INTRODUCTION

network management capabilities, you can reverse this configuration to
have the fiber port act as the repeater port and have the AUI port off. This
configuration allows you to connect the IRM-2 to a fiber optic link
segment directly without the need for an external fiber optic transceiver.

A standard 9 pin RS232 console port that enables you to locally access
IRM2/LM, and a Reset Switch to initialize the IRM-2's processor are also
built into the IRM-2's front panel.

The IRM-2 also incorporates Cabletron Systems’ LANVIEW Status
Monitoring and Diagnostic System. Should a problem arise, such as a
power failure or a cable fault, LANVIEW’s LEDs will help you to
diagnose it. LANVIEW LEDs on the IRM-2 advise you whether the
module is receiving power, whether an error has been detected with the
IRM-2, whether the IRM-2 is receiving packets from any segment
connected to the MMAC, or whether the module is detecting a collision
from the network.

1.4 REPEATER FUNCTIONALITY

The IRM-2’s IEEE 802.3 compliant repeater provides the MMAC with
the ability to achieve maximum data paths on all Ethernet transmission
media, including 10BASE-T Twisted Pair, Fiber Optic, and Thick or Thin
Ethernet type cabling. To attain these maximum data paths, the IRM-2
retimes data packets and regenerates the preamble of each data packet that
enters the MMAC.

In addition, the IRM-2’s repeater functionality assures that problem
segments connected to any port on the MMAC will not affect any other
segments connected to the MMAC. If 33 consecutive collisions are
detected on any segment, or if a collision detector is on for more than 2.4
msec, the IRM-2 will automatically partition that segment from the
MMAC. The segment will automatically be reconnected to the MMAC
when a packet is transmitted onto the segment without causing a collision.

1.5 NETWORK MANAGEMENT CAPABILITIES

The Cabletron Systems IRM-2 can be controlled and managed by a
variety of network management packages. These include:

1-4

INTRODUCTION

• Cabletron Systems SPECTRUM™

• Cabletron Systems Remote LANVIEW/Windows™

• Cabletron Systems IRM2/LM™ (Local Management)

• Third Party SNMP compliant Network Management Packages.
The IRM-2’s network management capabilities provide the necessary

management tools for the IRM-2 to operate at its full capacity. Your
ability to set up parameters within the network management capabilities
ensures optimal performance of the IRM-2, and, hence, the network.

For example, vast amount of statistical information is gathered by the
IRM-2, including the number of:

• Packets • Receive Collisions

• Transmit Collisions • Giant Packets

• Runt Packets • Misaligned Packets

• CRC errors • Out of Window Collisions

• Bytes Received.
For further specific information, refer to the applicable Network

Management Package User’s Manual.

1.6 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’

LAN-MD

User’s Manual.

1-5

CHAPTER 2

NETWORK REQUIREMENTS/SPECIFICATIONS

Before you attempt to install Cabletron Systems’ IRM-2, review all
requirements outlined in this chapter. Also, refer to the operating
specifications and environmental requirements that are listed.

All conditions, guidelines, specifications, and requirements included in
this chapter must be met to ensure satisfactory performance of the IRM-2.
Failure to follow these guidelines will result in unsatisfactory network
performance.

2.1 NETWORK REQUIREMENTS

When connecting network segments to the IRM-2, you must follow the
network guidelines listed below:

2.1.1 AUI Port Requirements

When connecting a network segment to the IRM-2, via a transceiver and
an AUI Cable, the following requirements must be met:

• The transceiver to which the IRM-2 will be connected must meet
Ethernet Version 2 or IEEE 802.3 standards.

• The AUI cables connecting the IRM-2 to the transceiver on the
network must be IEEE 802.3 type cables and must not exceed 50
meters in length.

2.1.2 Fiber Optic Port Requirements

When connecting a Fiber Optic Link Segment to the IRM-2’s fiber optic
ST ports, the following requirements must be met:

•

Cable T ype

the following:

-

50/125 µm fiber optic cabling.

- The fiber optic link segment should be made of one of

-

62.5/125 µm fiber optic cabling.

-

100/140 µm fiber optic cabling.

2-1

NETWORK REQUIREMENTS/SPECIFICATIONS

•

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.

•

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

- The maximum allowable fiber optic cable length is 3 Km.

However, IEEE 802.3 specifications allow for a maximum of 1 Km.

2.2 OPERATING SPECIFICATIONS

The operating specifications for Cabletron Systems’ IRM-2 are included
in this section. Cabletron Systems reserves the right to change these
specifications at any time without notice.

REPEATER FUNCTIONALITY

Delay Times (Port x In To Port x out)

Start of Packet: 1450 ns max.
Collision to JAM: 1550 ns max.

Preamble

Input: Minimum of 40 bits to a maxi-

mum of 64 bits required.

Output: 64 bits min (last 2 bits are 1, 1).

2-2

NETWORK REQUIREMENTS/SPECIFICATIONS

REPEATER FUNCTIONALITY (Cont.)

JAM Output: If a collision occurs on one of the

segments, a pattern of 1, 0 is sent to
the other segments.

Minimum Packet Repeated: 96 bits including preamble (Packet

fragments are extended using the
JAM [1, 0] data pattern).

FAULT Protection: Each segment will disconnect

itself from the other segments if 33
consecutive collisions occur, or if
the collision detector of a segment
is on for longer than
approximately 2.4 ms. This
FAULT protection will reset
automatically after one packet is
transmitted onto the FAULT pro­tected segment without
causing a collision.

FRONT PANEL INDICATORS

ERR (Error) When lit, this LED indicates that a

problem has been detected with the
IRM-2 (red indicator).

PWR (Power) When lit, this LED indicates that

the IRM-2 is receiving power from
the MMAC (green
indicator).

RCV (Receive) When lit, this LED indicates the

IRM-2 is repeating a data packet
received from one of the
segments connected to the MMAC
(yellow indicator).

XMT (Transmit) When lit, this LED indicates the

IRM-2 is transmitting a data packet
out to all other segments connected
to the MMAC (green indicator).

2-3

NETWORK REQUIREMENTS/SPECIFICATIONS

FRONT PANEL INDICATORS (Cont.)

CLN (Collision Present) When lit, this LED indicates the

IRM-2 is detecting a collision
signal from one of the segments
connected to the MMAC (red in­dicator).

POK (Port OK) When lit, this LED indicates that

the Network Interface Chip asso­ciated with the IRM-2’s internal
repeater port has passed an inter­nal Loop Back Test and is ready
for transmission (green indica­tor).

POK1 (Port OK) When lit, this LED indicates that

the Network Interface Chip asso­ciated with the IRM-2’s fiber op­tic and AUI ports on the IRM-2
has passed an internal Loop
Back Test and is ready for trans­mission (green indicator).

RCV1 (Receive) When lit, this LED indicates the

IRM-2 is repeating a data packet
received from the segment con­nected to the IRM-2 AUI Port or
Fiber Optic Port (yellow indica­tor).

LNK (Link) When lit, this LED indicates that

a link has been established be­tween the fiber optic port on the
IRM-2 and the fiber optic device
at the other end of the fiber optic
link segment (green indicator).

2-4

NETWORK REQUIREMENTS/SPECIFICATIONS

CONSOLE PORT

Type: Standard 9 pin RS232 Port

Pin 1 Not Used Pin Not Used

2 Transmit (TXD) 7 Ready to Send (RTS)
3 Receive (RXD) 8 Clear to Send (CTS)
4 Not Used 9 Not Used

AUI PORT

Type: 15 position D type receptacle

Pin 1 Logic Ref. PinCollision -

2 Collision + 10 Transmit ­3 Transmit + 11 Logic Ref.
4 Logic Ref. 12 Receive ­5 Receive + 13 Power (+12 Vdc)
6 Power Return 14 Logic Ref.
7 No Connection 15 No Connection
8 Logic Ref.

Connector Shell: Protective Ground

FIBER OPTIC INTERFACE

Internal Transceiver: Cabletron Systems’ FOT-F™

Fiber Optic Transceiver

Type: ST Ports

2-5

NETWORK REQUIREMENTS/SPECIFICATIONS

FIBER OPTIC INTERFACE (Cont.)

Parameter

Receive Sensitivity: -30.5 dBm -28.0 dBm — —

Peak Input Power: -7.6 dBm -8.2 dBm — —
Transmitter Power

50/125 µm fiber: -13.0 dBm -15.0 dBm 13.0 dB 17.5 dB

62.5/125 µm fiber: -10.0 dBm -12.0 dBm 16.0 dB 20.5 dB
100/140 µm fiber: 7.0 dBm -9.0 dBm 19.0 dB 23.5 dB

Typical

Value

Error Rate: Better than 10

NOTE:

above are Peak Power Levels after optical overshoot. A Peak Power
Meter must be used to correctly compare the values giv en abo v e to those
measured on any particular port. If P o wer Le vels are being measured with
an Av erage Power Meter, then 3 dBm must be added to the measurement
to correctly compare those measured values to the values listed above
(i.e. -30.5 dBm peak=-33.5 dBm average).

The transmitter power levels and receive sensitivity levels given

-10

Worst

Case

Worst Case

Budget

Typical

Budget

ENVIRONMENTAL REQUIREMENTS

Operating Temperature: +5° to +40°C (+41° to +104°F)
Non-operating Temperature: -30
Operating Humidity: 5 to 95% (non-condensing)

SAFETY

Designed in accordance with UL478, UL910, NEC 725-2(b), CSA, IEC,
TUV, VDE class A Meets FCC part 15, Class A limits.

WARNING

system of which the IRM-2 will be a part to ensure that the total
system meets allowed limits of conducted and radiated emissions.

2-6

: It is the responsibility of the person who sells the

°

to +90°C (-22° to +160°F)

NETWORK REQUIREMENTS/SPECIFICATIONS

Service

MTBF (MHBK-217): >35,543 hrs. projected
MTTR <0.5 hrs.

Physical Properties

Dimensions: 34.07D x 29.21H x 2.54W cm.

(13.4D x 11.5H x 1.0 W inches)

Weight:

Unit: 0.85 kg (1.95 lbs)
Shipping: 1.34 kg (2.95 lbs)

2-7

NETWORK REQUIREMENTS/SPECIFICATIONS

2-8

CHAPTER 3

INST ALLING THE IRM-2

This chapter contains instructions for installing the Cabletron Systems
IRM-2 into a Cabletron Systems MMAC. Additional instructions are
provided on setting the mode switches and connecting segments to the
IRM-2.

3.1 UNP ACKING THE IRM-2

Before you install the IRM-2, you should visually inspect the module.
Unpack the module as follows:

1. Remove the shipping material covering the IRM-2 in the shipping box.

2. Carefully remove the module from the shipping box. Leave the
module in its conductive bag until you are ready to install it. Save the
shipping box and materials in the event the unit has to be reshipped.

3. Visually inspect the module. If any damage appears to have occurred,
contact Cabletron Systems’ Technical Support immediately.

3.2 SETTING THE IRM-2 JUMPERS

There are eight jumpers on the IRM-2. See Figure 3-1. Three of the
jumpers, H1, H6, and JP1 can be changed. The remaining jumpers are for
Cabletron Systems use only and should not be changed from their default
positions.

3.2.1 Setting the Battery Enable/Disable Jumper (H1)

The Battery Enable/Disable Jumper (H1, Fig. 3-1) allows you to enable
or disable the Battery Backed-up RAM on the IRM-2. When set to the
Enabled position, all parameters that you enter into the IRM-2 will be
saved if power should fail to the MMAC, or if the IRM-2

3-1

INST ALLING THE IRM-2

H5

H1

Battery

Enable/Disable

Cabletron Systems

Use Only

B
A
C
K
P
L
A
N
E

H4

Cabletron Systems

Use Only

H2

Cabletron Systems

Use Only

H3

Cabletron Systems

Use Only

F
R
O
N
T
P
A
N
E
L

JP1

THN-MIM

Jumper

H7

Cabletron Systems

Use Only

H6

Clear to Send

External/Internal

-2

-1

PIN

NUMBERS

FOR JP1

123

PIN

NUMBERS

FOR H1, H6

Figure 3-1 IRM-2 Jumper Locations

is removed from the MMAC. When set to the disabled position, all
parameters entered into the IRM-2 will be lost.

To set the Battery Enable/Disable Jumper:

• To enable the Battery Backed-up RAM, place the jumper over Pins 1
and 2. This is the position in which the IRM-2 is shipped.

• To disable the Battery Backed-up RAM, place the jumper ov er Pins 2
and 3.

3-2

INST ALLING THE IRM-2

3.2.2 Setting the CTS External/Internal Jumper (H6)

The IRM-2’s Console Port is an RS-232 interface that uses Request-to­Send (RTS), Clear to Send (CTS), and Data Terminal Ready (DTR) to
control data flow. If the device connected to the Console Port does not
provide Request-to-Send (RTS) or Data Terminal Ready (DTR), the
IRM-2 must be configured to compensate (internally) for the lack of these
signals. In those situations, the CTS External/Internal Jumper
(H6, Fig. 3-1) allows the IRM-2 to generate the Clear to Send Signal
(CTS) internally. Refer to your device's User's Manual to determine the
requirements for this jumper setting.

To set the CTS External/Internal Jumper:

• If RTS or DTR is generated by your device to the IRM-2, place the

jumper over Pins 1 and 2. This is the position in which the IRM-2 is
shipped.

• If RTS or DTR must be generated internally by the IRM-2, place the

jumper over Pins 2 and 3.

3.2.3 Setting the THN-MIM Jumper (JP1)

Dependent on the revision level of the THN-MIMs installed in your
MMAC, the THN-MIM™ Jumper (JP1, Fig. 3-1) will need to be set.

To set the THN-MIM Jumper:

• If you are using THN-MIM part numbers 9000043-06 and above in

your MMAC, place the jumper over the center pin and pin-2.

• If you are using THN-MIM part numbers 9000043-05 and below in

your MMAC, place the jumper over the center pin and pin -1. This is
the position in which the IRM-2 is shipped.

CAUTION: If THN-MIM part numbers 9000043-05 and below and -06 and
above are both installed in your MMAC, the THN-MIM Jumper must be
placed over pin -1.

3.3 INST ALLING THE IRM-2

The IRM-2 is designed to be easily installed into an MMAC. No special
skills or tools are required to install the IRM-2.

3-3

INST ALLING THE IRM-2

When you install the IRM-2 into an MMAC, the following guidelines
must be followed:

• The IRM-2 must be installed into Slot 0 of the MMAC.

• If the module is going to be installed into an MMAC-8/MMA C-8FNB/
MMAC-5FNB, be sure a Power Supply Module (PSM™, PSM-R™,
MMAC-5PSM) is installed in the MMAC to supply power to the
IRM-2. The MMAC-3/MMAC-3FNB have a built-in power supply.

Install the IRM-2 into the MMAC as follows:

1. Power off the MMAC.

2. Slide the IRM-2 (2, Fig. 3-2) into Slot 0 (4) of the MMAC’s (1) card
cage. Be sure that the card is in the top and bottom slot guides.

1
2

IRM-2

SN

RCV1

RESET

T
X

R
X

ETHERNET

M
M
A
C

ERR
PWR
RCV
XMT
CLN
POK
POK1

C
O
N
S
O
L
E

A
U
I

LNK

F
O
I
R
L

3

3

4

3-4

1. MMAC

2. IRM-2

3. Knurled Knobs

4. Slot 0

Figure 3-2 Installation

INST ALLING THE IRM-2

3. Secure the Module to the MMAC by turning the knurled knobs (3). Be

sure that the module is firmly attached to the MMAC. Failure to do so
may result in improper operation.

4. Power on the MMAC.

5. Observe the status of the LANVIEW LEDs on the IRM-2. See Figure

3-3. After approximately 2 seconds, the LEDs should be in the
following conditions:

• PWR lit, indicating that the IRM-2 is receiving power.

• POK and POK1 LEDs lit, indicating that the network interface chip

associated with the IRM-2’s internal and external repeater ports have
passed the internal loopback test and are now ready for transmission.

3.4 SELECTING THE REPEATER PORT

When the IRM-2 is first powered up, the A UI port acts as the repeater port
and the Fiber ports are redundant. This configuration can be altered using
IRM-2’s network management capabilities so that the Fiber ports act as
the repeater port and the AUI port is redundant.

For further information, refer to the discussion of Port Association in the
applicable User’s Manual.

3.5 CONNECTING THE IRM-2 TO THE NETWORK

This section provides procedures for connecting the IRM-2 to the network
via the AUI Port or the Fiber Optic Ports.

3.5.1 Connecting to the Network Via the AUI Port

To connect to the network via the AUI Port:

CAUTION: Be sure to disable the SQE test function on the transceiver
you will be connecting to the IRM-2's AUI Port. Failure to do so will result
in improper operation of the IRM-2. Refer to the applicable transceiver
manual.

3-5

INST ALLING THE IRM-2

IRM-2

SN

RCV1

M
M
A
C

ERR
PWR
RCV

XMT
CLN

POK
POK1

C
O
N

S

O

L
E

MMAC
LANVIEW LEDs

RESET

A
U

I

LNK

T
X

R
X

ETHERNET

F

O

I

R

L

Fiber Optic Ports
LANVIEW LEDs

Figure 3-3 LANVIEW LEDs

3-6

INST ALLING THE IRM-2

1. Attach an external transceiver to the segment to which the AUI Port

will be attached. Refer to the applicable transceiver manual.

2. Attach the female end of an AUI cable, no more than 50 meters in

length, to the transceiver.

3. Attach the male connector on the AUI cable (3, Fig. 3-4) to the AUI

port (2) on the IRM-2.

4. Move the slide latch (1) on the AUI Port to secure it to the lock post

on the AUI connector.

1

1. Slide Latch

2. AUI port

2

A
U

I

3. AUI Connector

3

Figure 3-4 Connecting to the AUI Port.

3-7

INST ALLING THE IRM-2

3.5.2 Connecting to the Network Via the Fiber Optic

Port

When connecting a fiber optic link segment to the IRM-2's Fiber Optic
Ports, you must keep the following in mind:

• ST connectors attach to ST ports much like BNC connectors attach to
BNC ports. The connector is inserted into the port with the alignment
key on the connector inserted into the alignment slot on the port. The
connector is then turned to lock it down.

• The physical communication link consists of two strands of fiber optic
cabling: the T ransmit (TX) and the Receive (RX). The T ransmit strand
from the applicable port on the module will be connected to the
Receive port of a fiber optic Ethernet device at the other end of the
segment. For example, TX of the applicable port on the module will go
to RX of the other fiber optic device. The Receive strand of the
applicable port on the module will be connected to the Transmit port
of the fiber optic Ethernet device. For example, RX of the applicable
port on the module will go to TX of the other fiber optic device.

We recommend that you label the fiber optic cable to indicate which fiber
is Receive and which is Transmit. When you buy fiber optic cable from
Cabletron Systems, it is labeled so that: at one end of the cable, one fiber
is labeled 1, and the other fiber is labeled 2. This pattern is repeated at the
other end of the cable. If you did not purchase your cable from Cabletron
Systems, be sure you have labeled your cable in the manner described
above.

CAUTION: Do not touch the ends of the fiber optic strands, and do not
let the ends come in contact with dust, dirt, or other contaminants.
Contamination of the ends can cause problems in data transmissions.
If the ends become contaminated, clean them with de-natured alcohol
using a soft, clean, lint free cloth.

To connect a fiber optic link segment to an IRM-2's FOIRL Fiber Optic
Ports:

1. Remove the protective plastic covers from the fiber optic ports and
from the ends of the connectors on each fiber strand.

2. Attach the fiber labeled 1 (4, Fig. 3-5) to the receive port, labeled RX
(3), on the module.

3. Attach the fiber labeled 2 (2) to the transmit port, labeled TX (1), on
the module.

3-8

T
X

R
X

INST ALLING THE IRM-2

1. T ransmit P ort

2. Fiber Labeled 2

1

3. Fiber Labeled 3

4. Receive Port

2

3

4

Figure 3-5 Connecting to the Fiber Optic Ports

4. At the other end of the fiber optic cable, attach the fiber labeled 1 to

the transmit port of the device.

5. Attach the fiber labeled 2 to the receive port.

6. Check that the LNK LED for the fiber port on the IRM-2 is lit

(Fig. 3-3). If the LED is not lit, perform each of the following steps
until it is:

a. Check that the power is turned on for the de vice at the other end of

the link.

b. Verify that the fiber strands are properly “crossed over” between

the IRM-2 and the fiber optic device at the other end of the fiber
optic link segment.

c. Verify that the fiber cable meets the dB loss specifications

outlined in Fiber Optic Network Requirements.

If a link still has not been established, contact Cabletron Systems’
Technical Support.

3-9

INST ALLING THE IRM-2

3-10

CHAPTER 4

TESTING AND LANVIEW

This section contains procedures to test the IRM-2 after it has been
connected to the network. Descriptions of the LANVIEW LEDs on the
IRM-2 are also provided.

4.1 INSTALLATION CHECK-OUT

After the IRM-2 is connected to the network, verify that packets can be
passed between the two Ethernet network segments via the

IRM-2. Two Ethernet node testers capable of generating valid data
packets, such as Cabletron Systems’ LAN-MDs™, are required for this
procedure.

Before you begin, test each Ethernet segment connected to the IRM-2 to
ensure that the segments meet IEEE 802.3 specification limits.

1. If you are testing a fiber optic link segment connected to the IRM-2’s

fiber optic ports, connect a LAN-MD to the device end of the link
segment, using a transceiver and an AUI cable.

If you are testing a segment connected to the IRM-2’s AUI port,
connect a LAN-MD to the segment, using a transceiver and an AUI
cable.

2. Select and run test 6 - SERVER on the LAN-MD connected in step 2.

3. Verify that the Test Status PASS LED is lit and that the Status Code

reads 000 or 001. If these two conditions are met, the
LAN-MD is now the SERVER unit and will act as a packet echoer

when used with another LAN-MD.

4. Using a transceiver and an AUI cable, connect another LAN-MD to

any other segment connected to the MMAC.

5. Select and run test 4 - NODE on the LAN-MD connected in the

previous step.

4-1

TESTING AND LANVIEW

6. Verify that this test passes. At least 100 packets should be sent and
received with no errors. Packets will be sent from this LAN-MD to the
other LAN-MD, acting as the Server, then echoed back.

When the IRM-2 has successfully completed these tests, the module is
ready for normal operation. If any failures were noted, please contact
Cabletron Systems’ Technical Support.

4.2 USING LANVIEW

The IRM-2 uses Cabletron Systems’ built-in visual diagnostic and status
monitoring system called LANVIEW (Fig. 4-1). With LANVIEW,
network troubleshooting personnel can quickly scan LANVIEW’s LEDs
to observe network status, or diagnose network problems.

ERROR (ERR) LED

When this red LED is lit, the CPU has detected a problem with the
IRM-2.

POWER (PWR) LED

When this green LED is lit, the IRM-2 is receiving power from the
MMAC.

RECEIVE (RCV) LED

When this yellow LED is flashing, the IRM-2 is repeating a data packet
received from one of the segments connected to the MMAC.

TRANSMIT (XMT) LED

When this green LED is flashing, the IRM-2 is transmitting a data packet
out to all segments connected to the MMAC.

COLLISION PRESENT (CLN) LED

When this red LED is flashing, this indicates that a collision is being
detected on one of the segments connected to the MMAC.

PORT OK (POK) LED

This green LED is lit to indicate that the Network Interface Chip
associated with the IRM-2’s internal repeater port has passed an internal
Loop Back Test and is ready for transmission.

4-2

IRM-2

SN

M
M
A
C

RCV1

ERR
PWR
RCV

XMT
CLN

POK
POK1

C

O

N
S

O

L
E

TESTING AND LANVIEW

MMAC
LANVIEW LEDs

RESET

A
U

I

LNK

T
X

R
X

ETHERNET

F

O

I

R

L

Fiber Optic Ports
LANVIEW LED

Figure 4-1 LANVIEW LEDs

4-3

TESTING AND LANVIEW

PORT OK 1 (POK1) LED

This green LED is lit to indicate that the Network Interface Chip
associated with the IRM-2’s external repeater port has passed an internal
Loop Back Test and is ready for transmission.

RECEIVE 1 (RCV1) LED

When this yellow LED is flashing, the IRM-2 is repeating a data packet
received from the segment connected to the IRM-2’s AUI or Fiber Optic
Port.

LINK (LNK) LED

When lit, this green LED indicates that a link has been established
between the receive circuitry of the IRM-2’s fiber optic port and the
transmit circuitry of the fiber optic device at the other end of the fiber
optic link segment. This LED remains lit as long as the link is maintained.

To ensure that a link is maintained, the port generates a 1 MHz idle signal
when it is not transmitting data.

4.3 USING THE RESET SWITCH

The IRM-2 incorporates a recessed Reset Switch, located above the AUI
port. See Figure 4-1. This Reset Switch will initialize the IRM-2
processor . This will not initialize the Battery backed-up RAM where your
network management parameters are stored.

To use the reset switch, use a small screw driver to press the switch in.
When this is done, the IRM-2 will initialize itself.

4-4