Cabletron Systems IRM User manual

INTELLIGENT REPEATER MODULE
(IRM)
INSTALLATION GUIDE
CABLETRON SYSTEMS, P.O. Box 5005, Rocheter, NH 03867-5005

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 ORRELATED 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 July 1991 by:
Cabletron Systems, Inc.
P.O. Box 5005, Rochester, NH 03867-5005
All Rights Reserved
Printed in the United States of America
Order number: 9030033-03 July 91
LANVIEW is a registered trademark of Cabletron Systems, Inc.
SPECTRUM, Remote LANVIEW/Windows, IRM, IRM/LM, MMAC-8, MMAC-8FNB ,
MMAC-5FNB, MMAC-3, MMAC-3FNB, PSM, PSM-R, MMAC-5PSM, THN-MIM , and
LAN-MD are trademarks of Cabletron Systems, Inc.

NOTICE
ii
FCC NOTICE
This device complies with Part 15 of 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.
WARNING : This equipment uses and generates and can radiate radio frequency energy and if not
installed properly and used in accordance with the instruction manual, may cause interference to radio
communications. It has been tested and found to comply with the limits for a Class A digital device
pursuant to Part 15 of FCC Rules, which are designed to provide reasonable protection against such
interference in a commercial environment. Operation of this equipment in a residential area is likely
to cause interference in which case the user at his own expense will be required to take whatever steps
may be necessary 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
branch circuits.
If necessary, the user should consult the dealer or an experienced radio/television technician for
additional suggestions. The user may33 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.

iii
CONTENTS
CHAPTER 1 INTRODUCTION
1.1 USING THIS MANUAL........................................................................1-1
1.2 GETTING HELP ....................................................................................1-2
1.3 THE INTELLIGENT REPEATER MODULE (IRM) ...........................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 Thin-Net Requirements....................................................2-1
2.2 OPERATING SPECIFICATION ...........................................................2-2
CHAPTER 3 INSTALLING THE IRM
3.1 UNPACKING THE IRM........................................................................3-1
3.2 SETTING THE IRM JUMPERS ..........................................................3-1
3.2.1 Setting the Battery Enable/Disable Jumper .....................3-1
3.2.2 Setting the Default Setting Jumper (JP4).........................3-3
3.2.3 Setting the THN-MIM Jumper (JP2)...............................3-3
3.3 INSTALLING THE IRM........................................................................3-4
3.4 CONNECTING THE IRM TO THE NETWORK .................................3-5
3.4.1 Connecting to the Network Via the AUI Port..................3-5
3.4.2 Connecting to the Network Via the BNC 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.............................................................4-3

CONTENTS
iv

1-1
CHAPTER 1
INTRODUCTION
Welcome to the Cabletron Systems Intelligent Repeater Module
(IRM™) Installation Guide
. We have designed this manual to serve as a
simple installation and reference guide for the IRM, and to explain the
capabilities and special features of the IRM. The IRM provides an IEEE
802.3 Repeater with 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 and its capabilities.
1.1 USINGTHIS MANUAL
Chapter 1, Introduction , discusses the capabilities of Cabletron Systems'
IRM. The chapter includes an explanation of the IRM's repeater
functionality and a discussion of the IRM's Management capabilities. The
chapter concludes with a list of related manuals.
Chapter 2,
Installation Requirements/Specifications , contains a list of
network requirements that must be met before you install the IRM. The
specifications for the IRM are also included in this chapter.
Chapter 3,
Installing the IRM , contains instructions for installing the
IRM into the MMAC. The chapter also includes instructions for
connecting the IRM to the network.
Chapter 4,
Testing and Troubleshooting , provides procedures for testing
and troubleshooting the installation of the IRM. 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.

INTRODUCTION
1-2
1.2 GETTING HELP
If you need additional support related to the Cabletron Systems IRM, 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)
The Cabletron Systems Intelligent Repeater Module (IRM) (Fig. 1-1) is
the heart of the Cabletron Systems Multi Media Access Center. The IRM
incorporates an IEEE 803.3 repeater to allow maximum data paths
between devices connected MMAC.
The IRM can be controlled and monitored by a variety of Cabletron
System Network Management packages. These include Cabletron
Systems Remote LANVIEW/Windows™ and Cabletron Systems
SPECTRUM™. Additionally, the IRM can be controlled and monitored
by IRM/LM™ - Local Management for the IRM via a terminal connected
locally.
The IRM incorporates three IEEE 802.3 compliant ports that connect to
external network segments: twoAUI ports and one BNC port. The AUI
ports allow 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. The BNC port can be
used to connect a Thin-Net Segment to the IRM.
A standard 9 pin RS232 console port that allows you to access IRM/LM
and a Reset Switch to initialize the IRM's processor are also built into the
IRM's front panel.
The IRM also incorporates Cabletron Systems' LANVIEW Status
Monitoring and Diagnostics Systems. 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 advise you whether the module
is receiving power, whether an error has been detected with the IRM,
whether the IRM is receiving packets from any segment

INTRODUCTION
1-3
Figure 1-1 Intelligent Repeater Module (IRM)
IRM
SN
R
C
K
FAIL CLN
1
M
A
U
3
2
3P
O
K
C
O
N
S
O
L
E
A
U
I
2
A
U
I
1
RESET
Reset Switch
15 Pin DB-15
AUI Ports
9 Pin RS232 Port
BNC Port
LANVIEW LEDs

INTRODUCTION
1-4
connected to the MMAC, or whether the module is detecting a collision
from the network.
1.4 REPEATER FUNCTIONALITY
The IRM'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
retimes data packets and regenerates the preamble of each data packet that
enters the MMAC.
In addition, the IRM's repeater functionality assures that any 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
ms, the IRM 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 can be controlled and managed by a variety
of network management packages. These include:
• Cabletron Systems' SPECTRUM
• Cabletron Systems' Remote LANVIEW/Windows
• Cabletron Systems' IRM/LM (Local Management)
The IRM's network management capabilities provide the necessary
management tools for the IRM to operate at its full capacity.Your ability
to set up parameters within these network management capabilities
ensures optimal performance of the IRM, and, hence, the network.
SNMP compliant management capabilities are also available for the IRM
monitoring by Third Party SNMP compliant Network Management
Packages.

INTRODUCTION
1-5
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.

INTRODUCTION
1-6

2-1
CHAPTER 2
NETWORK REQUIREMENTS/SPECIFICATIONS
Before you attempt to install Cabletron Systems' IRM, 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.
Failure to follow these guidelines will result in unsatisfactory network
performance.
2.1 NETWORK REQUIREMENTS
When connecting network segments to the IRM, you must follow the
network guidelines listed below:
2.1.1 AUI Port Requirements
When connecting a network segment to the IRM, via a transceiver and an
AUI Cable, the following requirements must be met:
• Transceiver - The transceiver to which the IRM will be connected
must meet Ethernet Version 2, or IEEE 802.3 standards.
• AUI Cable - The AUI cable connecting the IRM to the transceiver on
the network must be IEEE 802.3 type cables and must not exceed 50
meters in length.
2.1.2 Thin-Net Requirements
When connecting a Thin-Net Segment to the IRM's BNC port, the
following requirements must be met:
• Cable Type - 50 ohm RG-58A/U type coaxial cable must be used
when making up a thin-net cable segment.

NETWORK REQUIREMENTS/SPECIFICATIONS
2-2
• Length - The thin-net segment must be no longer than 185 meters.
•
Terminations -A50 ohm terminator must beconnectedtothe farends
of each thin-net segment. The BNC port on the IRM is not internally
terminated.
•
Connections - A maximum of 29 tee-connectors may be used
throughout the length of cable segment for host connections. If an
excessive number of barrel connectors are used within the cable
segment, such as finished wall plates with BNC feed-throughs, then a
reduced number of host connections may be required. For special
network design, contact Cabletron Systems’Technical Support.
•
Grounding - For safety, only one end of a thin-net segment should be
connected to earth ground. Connection to earth ground at more than
one point on the segment may allow for the occurrence of dangerous
ground currents.
The IRM's BNC port is not connected to earth ground.
2.2 OPERATING SPECIFICATIONS
The operating specifications for Cabletron Systems' IRM 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 maximum of
64 bits required.
Output: 64 bits min (last 2 bits are 1,1).

NETWORK REQUIREMENTS/SPECIFICATIONS
2-3
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, O] data pattern).
FAULT Protection: Each segment will disconnect itself
from the other segments if 33
consecutivecollisions occur,orif 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
Fail (Error)
When lit, this LED indicates that a
problem has been detected with the
IRM (red indicator).
CLN (Collision Present) Whenlit, thisLEDindicates theIRM
is detecting a collision signal from
one of the segments connected to the
MMAC (red indicator).
Unlabeled (Yellow LED) When lit this LED indicates that the
IRM is receiving network
management packets.
Unlabeled (Green LED) When lit this LED indicates that the
IRM network management
capabilities are on line and
functional.

NETWORK REQUIREMENTS/SPECIFICATIONS
2-4
FRONT PANEL INDICATORS (Cont..)
NOTE: There is one Receive and Port OK LED for each AUI Port, Ports 1
and 2, and the BNC Port, Port 3.
RCV (Receive) Whenlit,thisLEDindicatestheIRMis
repeating a data packet received from
the segment connected to the port
(yellow indicator).
POK (Port OK ) When lit, this LED indicates that the
Network Interface Chip associated
with the port has passed an internal
Loop Back Test and is ready for
transmission (green indicator).
CONSOLE PORT
Type: Standard 9 pin RS232 Port
Pin 1 Not Used Pin 6 Not Used
2 Transmit (TXD) 7 Ready to Send (RTS)
3 Receive (RXD) 8 Clear to Send (CTS)
4 Not Used 9 Not Used
5 Logic Ref.
AUI PORT
Type: 15 position D type receptacle
Pin 1 Logic Ref. Pin 9 Collision -
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

NETWORK REQUIREMENTS/SPECIFICATIONS
2-5
BNC IN'IREFACE
Internal Transceiver: Cabletron Systems' TMS-3™
Transceiver.
Type: BNC receptacle, with gold center
contact, for use with BNC type
tee-connectors and RG-58 thin-net
cable.
ENVIRONMENTAL REQUIREMENTS
Operating Temperature: +5 ° to +40 ° C (+41 ° to +104 ° F)
Non-operating Temperature: -30
° to +90 ° C (-22 ° to +160 ° F)
Operating Humidity: 5 to 95% (non-condensing)
SAFETY
Designed in accordance with UL478, UL910, NEC 725-2(b), CSA,
IEC, TW, VDE class A. Meets FCC part 15, Class A limits.
WARNING : It is the responsibility of the person who sells the system of
which the IRM will be a part to ensure that the total system meets allowed
limits of conducted and radiated emissions.
SERVlCE
MTBF (MHBK-217): >150,093 hrs. projected
MTTR <0.5 hr.

NETWORK REQUIREMENTS/SPECIFICATIONS
2-6
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)

3-1
CHAPTER 3
INSTALLINGTHE IRM
This chapter contains instructions for installing the Cabletron Systems
IRM into a Cabletron Systems' MMAC. Additional instructions are
provided on setting the mode switches and for connecting segments to the
IRM.
3.1 UNPACKINGTHE IRM
Before you install the IRM, you should visually inspect the module.
Unpack the module as follows:
1. Remove the shipping material covering the IRM 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 SETTINGTHE IRM JUMPERS
On the IRM are five jumpers (See Figure 3-1). Three of the jumpers, JP2,
JP4, and JP5, can be changed. JP1 is for Cabletron Systems use only and
should not be changed from its default positions. JP3 is not used.
3.2.1 Setting the Battery Enable/Disable Jumper (JP5)
The Battery Enable/Disable Jumper (JP5, Fig. 3-1) allows you to enable
or disable the Battery Backed-up RAM on the IRM. When set to the
Enabled position, all parameters that you enter into the IRM

INSTALLINGTHE IRM
3-2
Figure 3-1 IRM Jumper Locations
will be saved if power should fail to the MMAC, or if the IRM is removed
from the MMAC. When set to the disabled position, all parameters
entered into the IRM will be lost after approximately 10 minutes.
To set the Battery Enable/Disable Jumper:
• To enable the Battery Backed-up RAM, place the jumper over Pins 1
and 2.
• To disable the Battery Backed-up RAM, place the jumper over Pins 2
and 3. This is the position in which the IRM is shipped.
JP5
Battery Jumper
JP4
Default Settings
Jumper JP3 Not Used
F
R
O
N
T
P
A
N
E
L
B
A
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K
P
L
A
N
E
JP2
TNH-MIM
Jumper
PIN
NUMBERS
JP1
Cabletron Systems’
Use Only
1 2 3