Cabletron Systems TDRMIM-42A, TDRMIM-22A User Manual

TDRMIM-22A/42A

TM

TOKEN RING DUAL REPEATER MIM

USER’S GUIDE

SW1

OFF ON

Switchblock SW1

TDRMIM Quick Reference Card

Front

Panel

Side View of the TDRMIM

12345678

1
2
3
4
5
6
7
8

FNB Ring 1 Speed Default:
[Leave OFF]
[Unused]
[Unused]

Ring Ports 1 Ring In
Ring Ports 1 Ring Out

Keying

Fiber Optic

Ring Ports 2 Ring In

Sequence

Ring Ports 2 Ring Out

Motherboard

Daughterboard

ON = 16 Mbps; OFF = 4 Mbps

ON = 802.5
OFF = ctron

Switchblock SW1 with Factory Default Settings

TRANSMIT +

RECEIVE ­RECEIVE +

TRANSMIT -

RJ45 Lobe Port Pinouts

8
7
6
5
4
3
2
1

QR-1

ALL LED SIGNALS

ERR
ERR

BYP
BYP

MGMT

MGMT

16 MB
16 MB

IN USE

IN USE

IN USE

G

R

G

G

Y

G

Normal operation
Hardware error condition, or reset in process
Module Bypass—No ports inserted in FNB rings
FNB interfaces active
Management control in effect

(hardware default switches overridden)
Hardware defaults in effect
16 Mbps ring speed in effect
4 Mbps ring speed in effect
Ring active

Ring active but bypassed from FNB
Ring inactive (no lobes connected)

12

12

12

12

12

PEN
PEN

LNK

LNK

G

R

G

R

G

G

Port enabled and transmitting
Port linked but disabled by management
Port in standby state
Speed Fault on linked port
Port disabled and not linked

Ring Port set enabled
Ring Port set disabled
Ring Port set linked
Ring Port set disabled, or autowrapped, or

not linked

LEGEND:

= GREEN

G

= RED = off

R

QR-2

= YELLOW

Y

G

R

= Blinking GREEN

= Blinking RED

NOTICE

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 July, 1995 by:
Cabletron Systems, Inc.
P.O. Box 5005, Rochester, NH 03866-0505

All Rights Reserved.

1

Printed in the United States of America.

Order Number 9031428 July, 1995.

FNB, MMAC, TRXMIM, TRBMIM, TDRMIM, TRMIM, TRMM-2,
4

are trademarks of Cabletron Systems, Inc.

Flexible Network Bus, Multi Media Access Center, SPECTRUM, LANVIEW

and

Remote LANVIEW

IBM

is a registered trademark of International Business Machines Corporation.

DEC

and

VT100

CompuServe

are trademarks of Digital Equipment Corporation.

is a registered trademark of CompuServe, Inc.

are registered trademarks of Cabletron Systems, Inc.

and

TRMM-

,

Printed on Recycled Paper

i

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: This equipment has been tested and found to comply with the limits for a
Class A digital device, pursuant to Part 15 of the FCC rules. These limits are
designed to provide reasonable protection against harmful interference when the
equipment is operated in a commercial environment. This equipment uses,
generates, and can radiate radio frequency energy and if not installed in
accordance with the operator’s manual, may cause harmful interference to radio
communications. Operation of this equipment in a residential area is likely to
cause interference in which case the user will be required to correct the interference
at his own expense.

WARNING: Changes or modifications made to this device which are not expressly
approved by the party responsible for compliance could void the user’s authority
to operate the equipment.

DOC NOTICE

2

3

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.

CABLETRON SYSTEMS, INC. PROGRAM LICENSE AGREEMENT

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

4

ii

NOTICE

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.

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.

You may not reverse engineer, decompile, or

EXCLUSION OF WARRANTY AND DISCLAIMER OF LIABILITY

1. EXCLUSION OF WARRANTY.

Cabletron in writing, Cabletron makes no warranty, expressed or implied,
concerning the Program (including Its documentation and media).

Except as may be specifically provided by

5

6

CABLETRON DISCLAIMS ALL WARRANTIES, OTHER THAN THOSE
SUPPLIED TO YOU 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.

2. NO LIABILITY FOR CONSEQUENTIAL DAMAGES

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 LIMITATIONS AND
EXCLUSIONS MAY NOT APPLY TO YOU.

. IN NO EVENT

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 03866

7

iv

CONTENTS

CHAPTER 1 Introduction

1.1 Using This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

1.2 About the TDRMIM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

1.2.1 Ring In/Ring Out Ports . . . . . . . . . . . . . . . . . . . . . .1-3

1.2.2 Lobe Ports. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4

1.2.3 Cluster Switching . . . . . . . . . . . . . . . . . . . . . . . . . .1-5

1.2.4 Automatic Configuration at Power-Up. . . . . . . . . . 1-7

1.2.5 Support for Passive MAU Workgroups . . . . . . . . . 1-8

1.2.6 Interaction with Other MIMs in the MMAC . . . . .1-8

1.2.7 LANVIEW LEDs . . . . . . . . . . . . . . . . . . . . . . . . .1-10

1.2.8 Network Management. . . . . . . . . . . . . . . . . . . . . . 1-10

1.3 Supplemental Information . . . . . . . . . . . . . . . . . . . . . . . . 1-10

1.3.1 Related Manuals . . . . . . . . . . . . . . . . . . . . . . . . . .1-10

1.3.2 Recommended Reading . . . . . . . . . . . . . . . . . . . . 1-10

1.3.3 Getting Help . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-11

CHAPTER 2 Requirements and Specifications

2.1 General Cabling Considerations. . . . . . . . . . . . . . . . . . . . . 2-1

2.1.1 Maximum Number of Stations on a Ring. . . . . . . .2-1

2.1.2 Crosstalk and Noise . . . . . . . . . . . . . . . . . . . . . . . .2-1

2.1.3 Installation Recommendations . . . . . . . . . . . . . . . .2-2

2.1.4 Network Performance Requirements . . . . . . . . . . . 2-2

2.2 UTP Cabling Specifications . . . . . . . . . . . . . . . . . . . . . . . . 2-3

2.2.1 UTP Cable Categories. . . . . . . . . . . . . . . . . . . . . . .2-3

2.2.2 UTP Cable Lengths to Stations. . . . . . . . . . . . . . . .2-5

2.3 STP Cabling Specifications . . . . . . . . . . . . . . . . . . . . . . . .2-5

2.3.1 STP Cable Categories. . . . . . . . . . . . . . . . . . . . . . . 2-5

2.3.2 STP Cable Lengths to Stations . . . . . . . . . . . . . . . . 2-6

2.4 Fiber Optic Cable Specifications . . . . . . . . . . . . . . . . . . . . 2-7

2.5 TDRMIM Operating Specifications . . . . . . . . . . . . . . . . . . 2-8

2.5.1 Switchblock SW1 . . . . . . . . . . . . . . . . . . . . . . . . . .2-8

2.5.2 Media Filters. . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-10

2.5.3 Connector Types. . . . . . . . . . . . . . . . . . . . . . . . . .2-10

2.5.4 Ring Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11

v

CONTENTS

2.5.5 LANVIEW LEDs . . . . . . . . . . . . . . . . . . . . . . . . .2-12

2.6 Other Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-12

2.6.1 Hardware Specifications. . . . . . . . . . . . . . . . . . . .2-12

2.6.2 Environmental Requirements . . . . . . . . . . . . . . . .2-12

2.6.3 Safety Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-12

2.6.4 Service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-13

CHAPTER 3 Installation

3.1 General Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3.2 Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1

3.2.1 Unpacking the TDRMIM . . . . . . . . . . . . . . . . . . . . 3-2

3.2.2 Setting Configuration Switches . . . . . . . . . . . . . . .3-2

3.2.3 Installing the TDRMIM into an MMAC . . . . . . . . 3-2

3.2.4 Boot-Up Check . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3

3.2.5 Connecting Twisted Pair Cabling. . . . . . . . . . . . . .3-4

3.2.6 Connecting Ring In/Ring Out Cables. . . . . . . . . . . 3-7

3.2.7 Pre-Operational Testing . . . . . . . . . . . . . . . . . . . . .3-7

CHAPTER 4 Testing and Troubleshooting

4.1 Installation Checkout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4.2 LANVIEW LED Signals . . . . . . . . . . . . . . . . . . . . . . . . . .4-2

APPENDIX A Introduction to Port Switching

A.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

A.2 The Flexible Network Bus (FNB). . . . . . . . . . . . . . . . . . . A-1

A.3 Without Port Switching. . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

A.4 With Port Switching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2

A.5 Configuration Specifications . . . . . . . . . . . . . . . . . . . . . . A-5

vi

CHAPTER 1

Introduction

Welcome to the

Media Interface Module User’s Guide

Token Ring Dual Port Repeater/Concentrator Switching

. This manual is a reference for the
installation and troubleshooting of Cabletron Systems’ TDRMIM-22A and
TDRMIM-42A modules, represented in Figure 1-1.

The TDRMIM is an active cluster-switching twisted pair concentrator with
dual multimode fiber Ring In/Out repeater ports for Token Ring
expansions. The IEEE 802.5 compliant and IBM compatible TDRMIM is
designed for installation into any Cabletron Systems Multi Media Access
Center (MMAC) equipped with a Flexible Network Bus (FNB).

TDRMIM-22A

1
x

2
x

3
x

4
x

5
x

6
x

SN

RING 1 16Mb
RING 2 16Mb
RING 3 16Mb
RING 4 16Mb

AUX 1 16Mb
AUX 2 16Mb

1
2
3
4
5
6

7
8
9
10
11
12

R

I
N
G

P
O
R
T
S

1

BYP

LNK PEN

RI

LNK PEN

RO

ERR
MGMT
IN USE
IN USE
IN USE
IN USE
IN USE
IN USE

TX

RX

TX

RX

TDRMIM-42A

1
x

2
x

3
x

4
x

5
x

6
x

SN

RING 1 16Mb
RING 2 16Mb
RING 3 16Mb
RING 4 16Mb

AUX 1 16Mb
AUX 2 16Mb

1
2
3
4
5
6

7
8
9
10
11
12

R

I
N
G

P
O
R
T
S

1

BYP

LNK PEN

RI

LNK PEN

RO

ERR
MGMT
IN USE
IN USE
IN USE
IN USE
IN USE
IN USE

TX

RX

TX

RX

Figure 1-1. TDRMIM -22A and TDRMIM-42A

7
x

8
x

9
x

10

x

11

x

12

x

DUAL FIBER REPEATER

LNK PEN

RI

R

I
N
G

P
O
R
T
S

LNK PEN

2

RO

UTP TOKEN RING

TX

RX

TX

RX

7
x

8
x

9
x

10

x

11

x

12

x

DUAL FIBER REPEATER

LNK PEN

RI

R

I
N
G

P
O
R
T
S

LNK PEN

2

RO

STP TOKEN RING

TX

RX

TX

RX

Page 1-1

Using This Manual

1.1 Using This Manual

Prior to installing and operating the TDRMIM, read through this manual
completely. If you are not familiar with port switching and four-ring FNB
applications, read Appendix A,
manual assumes users to have a working knowledge of Token Ring (IEEE

802.5) networks.

Introduction to Port Switching

. This

Chapter 1,

Introduction

, describes how to use this document, provides an
overview of the features and capabilities of the TDRMIM, and concludes
with a list of related manuals.

Chapter 2,

Requirements and Specifications

, lists the network
requirements that must be met before installation, and provides detailed
specifications for the TDRMIM.

Chapter 3,

Installation

, contains instructions for installing the TDRMIM

into an MMAC and attaching Token Ring station cabling.

Chapter 4,

Testing and Troubleshooting

, describes diagnostic checks to
assist in the correction of post-installation problems, and provides
detailed descriptions of LANVIEW LEDs, Cabletron Systems’ visual
diagnostic and status monitoring system.

Appendix A,

Introduction to Four-Ring FNB Functionality,

discusses the

concepts of port switching and port assignment.

1.2 About the TDRMIM

The TDRMIM expands MMAC connectivity through two sets of
multimode fiber optic Ring In and Ring Out ports and twelve active lobe
ports. Designed for use with the TRMM-2 and TRMM-4 Token Ring
Management Modules, it provides MMAC users with the ability to extend
FNB backplane rings through other devices to form collapsed backbone
configurations, and increases connectivity in the hub by 12 lobe ports. The
TDRMIM also offers the following features:

• Complete compatibility with all Token Ring MIMs

• Cluster switching

• Automatic speed fault protection

• Full back-up path redundancy protection from ring out cable faults

• Full signal retiming on Ring In and Ring Out ports

• Active lobe ports for twisted pair connections

Page 1-2

About the TDRMIM

IN USE

RING 2 16Mb

• Cable fault Autowrap on fiber optic trunk ports

• Multi Ring Out connectivity for passive MAU workgroups

• LANVIEW LEDs for “at-a-glance” diagnostic monitoring

1.2.1 Ring In/Ring Out Ports

The dual multimode fiber Ring Port sets (Ring Ports 1 and Ring Ports 2)
support two fully redundant ring extensions to other hubs up to 2 Km
away from the MMAC. As shown in Figure 1-2, each Ring Port set consists
of four ST connectors—a pair of Transmit and Receive ports for Ring In
and another pair for Ring Out.

7
8
9
10
11
12

R
I
N

G
P

O
R

T
S

1

LNK PEN

RI

LNK PEN

RO

LNK PEN

IN USE
IN USE
IN USE
IN USE

TX

RX

TX

RX

1 Ring Ports set = 4 cable connections

Transmit

Ring In

Receive

Transmit

ST Connectors

Ring Out

Receive

Ring Ports 1

1
x

2
x

3
x

4
x

5
x

6
x

7
x

RING 3 16Mb
RING 4 16Mb

AUX 1 16Mb
AUX 2 16Mb

1
2
3
4
5
6

Figure 1-2. One Ring Port Set

With these Ring Ports, two otherwise isolated Token Rings may be joined
via two cable sets—one Ring In and one Ring Out. This is known as a fully
redundant connection because, as both cable sets contain a Transmit line
and a Receive line, either cable set is capable of maintaining the connection
without the other. Under normal operating conditions, only half of each
cable set is active—the Transmit line on the Ring Out set and the Receive
line on the Ring In set. If either cable set fails, the other maintains the ring
connection by automatically activating the second line in its
Receive/Transmit pair to provide a backup path.

Refer to Section 1.2.3,
assignments.

Cluster Switching

, for details about FNB Ring

Page 1-3

About the TDRMIM

Repeater Circuitry

The Ring Port sets provide circuitry that completely retimes and repeats
all received signals before transmitting them to the next point on the ring.
This enhances signal integrity and makes adjusted ring length (ARL)
computations unnecessary: maximum trunk cable distances are extended
to 2 Km.

Ring Speed Fault Protection

TDRMIMs provide ring speed fault protection on each Ring Port to protect
against beaconing conditions caused by ring speed mismatches between
the host hub’s ring and the ring on the externally connected hub. If there
is a mismatch between the ring speeds of the incoming signal and the
destination ring, the TDRMIM keeps the Ring Port looped back on itself to
protect the hub from the conflict. When the speed mismatch condition is
eliminated, the port comes out of loopback mode.

1.2.2 Lobe Ports

1

2

Each TDRMIM is equipped with 12 lobe ports—female RJ45 modular
connector jacks—for TCU (Trunk Coupling Unit) or Multi Ring Out
connections. TDRMIM-22A supports UTP cabling (Unshielded Twisted
Pair) and TDRMIM-42A supports STP (Shielded Twisted Pair). The RJ45
connectors used in the TDRMIM-42A (for STP cabling) provide a
grounded connection for the cabling shield.

Refer to Section 1.2.3,

Cluster Switching

, for details about port-to-FNB

Ring assignments.

TCU and Multi Ring Out Configurations

BY default, each lobe port on the TDRMIM operates as a TCU to support
the insertion of a Token Ring station into a ring; however the Local
Management (LM) application on a management module (such as
TRMM-4) may be used to reconfigure any of these TCU ports to function
as Multi Ring Out ports to support the connection of passive network
devices. See Section 1.2.5,

Support for Passive MAU Workgroups

.

1

Active Circuitry

Each lobe port provides circuitry which filters, equalizes, and amplifies all
received signals before transmitting them to the next point on the ring. The

Page 1-4

2

About the TDRMIM

82

result is enhanced signal integrity and extended maximum lobe cable
distances. For length specifications for UTP and STP lobe cables, see
Section 2.2.2,

Lengths to Stations

UTP Cable Lengths to Stations

.

and Section 2.3.2,

STP Cable

Ring Speed Fault Protection

TDRMIMs provide Ring Speed Fault Protection on each lobe port to
protect against beaconing conditions caused by stations inserting at the
wrong ring speed. If there is a mismatch between the ring speeds of the
incoming signal and the destination ring, the TDRMIM keeps the lobe port
looped back on itself to keep the misconfigured station from disrupting
the ring. When the mismatch condition is eliminated, the port comes out
of loopback mode.

1.2.3 Cluster Switching

The ports of the TDRMIM are permanently grouped into two Clusters:
Cluster 1 comprises lobe ports 1-6 and Ring Ports 1, Cluster 2 comprises
lobe ports 7-12 and Ring Ports 2 (see Figure 1-3). These Clusters switch as
collective units; rather than taking port assignments on a port-by-port
basis, TDRMIMs take assignments on a per-Cluster basis and switch their
corresponding ports collectively. The TDRMIM is therefore called a
cluster-switching MIM.

3

93
104
115
126

1

LNK

PEN

TX

RI

RX

LNK

PEN

LNK

PEN

Lobe Ports 1-6

Ring Ports 1

Lobe Ports 7-12

LNK

PEN

Ring Ports 2

Cluster 1

Cluster 2

X
2

X
3

X
4

X
5

X
6

X

7
X

8
X

9
X

10

X

11

X

12

X

Figure 1-3. Port Clusters of the TDRMIM

and

and

Page 1-5

About the TDRMIM

Port-Switching MIMs

As with port-switching MIMs, the cluster-switching TDRMIM requires
the support of a port-assigning management module such as the TRMM-2
or TRMM-4 to switch its connections. With this support, the Clusters may
be individually assigned to any of the four vertically stacked FNB rings
(illustrated in Figure 1-4) on the MMAC backplane.

TRMM-4

CRM2-R/T

TSXMIM

TDRMIM

TRXMIM

TRXMIM

TRXMIM

TRXMIM

FNB ring 1
FNB ring 2
FNB ring 3
FNB ring 4

Figure 1-4. FNB Expanded to Four Rings by Port Switching MIMs

To assign and change a Cluster’s FNB connection from one ring to another,
simply issue a new port assignment through the network management
interface provided by a port-assigning management module such as the
TRMM-2/TRMM-4 or through a remote management system (see Section

1.2.8,

Network Management

). The TDRMIM receives such commands

and switches the specified Cluster’s connection internally.

Either Cluster may be assigned to any of the four FNB rings. When a
Cluster is switched, all stations and ring extensions attached through the
Cluster’s lobe ports and ring ports are thereby transplanted onto the
newly assigned ring. Therefore, when preparing to switch a Cluster’s ring
assignment, take care to consider the number of stations currently inserted
on the proposed destination ring and the number inserted through the
Cluster to be switched. If the total number of stations inserted in these two
locations exceeds the maximum station limit for a single ring, do not
execute the switch. Also, make sure that the rings are operating at the
same ring speed.

NOTE

When using the TDRMIM in an MMAC managed by a TRMM-2,
which has a permanent interface with FNB ring 1, the firmware on
the TRMM-2 rejects instructions to switch either Cluster onto

Page 1-6

About the TDRMIM

FNB 1 while the TRMM-2’s STATION port interface is operating
through that Cluster. For if allowed, such a switch would create the
prohibited condition of redundant management on FNB 1.

1.2.4 Automatic Configuration at Power-Up

The management module in the TDRMIM’s host MMAC stores all
user-configured ring assignments and speed settings in its battery-backed
NVRAM (Non-Volatile Random Access Memory). Upon TDRMIM reset,
the MMAC’s resident management module reissues its stored
configurations to the TDRMIM so that all ring assignments and speed
settings established before power-down are reinstated at next power-up.

Instructions from a management module always override the TDRMIM’s
hardware defaults. However, there are two conditions under which the
TDRMIM will not receive management configuration instructions:

• no functional management module is present in the hub; or

• the TDRMIM is not recognized by the management module—either
the TDRMIM is powering up for the first time in its current hub slot,
or the latest hub configuration has been cleared from the management
module’s NVRAM.

If the TDRMIM does not receive management configuration instructions
at start-up, it uses its hardware defaults for ring speed and ring
assignment configurations.

Hardware Default Configuration

The TDRMIM’s default ring speed for FNB Ring 1 is user-configurable.
Use Switch #1 on SW1 (see Section 2.5.1,

Switchblock SW1

) to select a
default ring speed of either 4 Mbps or 16 Mbps for FNB Ring 1. All other
rings default to 16 Mbps.

The TDRMIM’s default ring assignments are factory set (are not
user-configurable): Cluster 1 defaults to FNB ring 1 and Cluster 2 defaults
to FNB ring 2. Because of these default assignments, even in the absence of
a port-assigning management module to address FNB rings 2-4, all
contiguously installed TDRMIMs connect to each other across both FNB
ring 1 and FNB ring 2. Therefore, in addition to the usual Token Ring on
FNB ring 1, TDRMIM defaults provide for a second fully viable (though
possibly unmanaged) Token Ring on FNB ring 2.

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