3Com 5112M-TPLS User Manual
®
ONline 10BASE-T Security
Module Installation and
Operation Guide
Document Number 17-00392-3
Printed February 1996
Model Number: 5112M-TPLS
3Com Co rporation
118 Turnpike Road
Southborough, MA 01772-1886
U.S.A.
(508) 460-8900
FAX (508) 460-8950
Federal Communications Commission Notice
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 generates, uses, and can
radiate radio frequency energy and, if not installed and used in
accordance with the instruction manual, may cause harmful
interference to radio communications. Operation of this equipment
in a residential area is likely to cause harmful interference, in which
case you must correct the interference at your own expense.
Canadian Emissions Requirements
Cet appareil numérique respecte les limites de bruits
radioélectriques applicables aux appareils numériques de Classe A
prescrites dans la norme sur la matériel brouilleur: "Appareils
Numériques", NMB-003 édictée par le Ministère des
Communications.
This digital apparatus does not exceed the Class A limits for radio
noise emissions from digital apparatus as set out in the
interference-causing equipment standard entitled "Digital
Apparatus", ICES-003 of the Departm en t of Communications.
VDE Class B Compliance
Hiermit wird bescheinigt, dass der 5112M-TPLS in
Üebereinstimmung mit den Bestimmungen der Vfg 243/1991
funkentstöert ist.
Der Deutschen Bundespost wurde das Inverkehrbringen dieses
Geraetes angezeigt und die Berechtigung zur Üeberprüefung der
Serie auf Einhaltung der Bestimmungen eingeräeumt.
Einhaltung mit betreffenden Bestimmugen kommt darauf an, dass
geschirmte Ausfuehrungen gebraucht werden. Fuer die
Beschaffung richtiger Ausfuehrungen ist der Betreiber
verantwortlich.
This is to certify that the 5112M-TPLS is shielded against radio
interference in accordance with the provisions of Vfg 243/1991.
The German Postal Services have been advised that this equipment
is being placed on the market and that they have been given the
right to inspect the series for compliance with regulations.
Compliance with applicable regulations depends on the use of
shielded cables. The user is responsible for procuring the
appropriate cables.
EN55022/CISPR22 Compliance
This equipment conforms to the Class A emissions limits for a
digital device as defined by EN55022 (CISPR22).
VCCI Class 1 Compliance
This equipment is in the 1st Class category (information equipment
to be used in commercial or industrial areas) and conforms to the
standards set by the Voluntary Control Council for Interference by
Information Technology Equipment aimed at preventing radio
interference in commercial or industrial areas.
Consequently, when the equipment is used in a residential area or
in an adjacent area, radio interference may be caused to radio and
TV receivers, and so on.
Read the instructions for correc t handling .
UK General Approval Statement
The ONcore Switching Hub, ONline System Concentrator, and
ONsemble StackSystem Hub are manufactured to the International
Safety Standard EN 60950 and are approved in the UK under the
General Approval Number NS/G/12345/J/100003 for indirect
connection to the public telecomm unication network.
Disclaimer
The information in this document is subject to change without
notice and should not be construed as a commitment by 3Com
Corporation. 3Com Corporation assumes no responsibility for any
errors that may appear in this document.
Copyright State me nt
©
1996, by 3Com Corporation. Printed in U.S.A. All rights reserved.
3Com is a registered trademark of 3Com Corporation. ONcore is a
registered trademark of 3Com Corporation. The information
contained herein is the exclusive and confidential property of
3Com Corporation. No part of this manual may be disclosed or
reproduced in whole or in part without permission from 3Com
Corporation.
Trademarks
Because of the nature of this material, numerous hardware and
software products are mentioned by name. In most, if not all
cases, these product names are claimed as tradem arks by th e
companies that manufacture the products. It is not our intent to
claim these names or trademarks as our own.
Artel, Chipcom, Ethermodem, Galactica, ONcore, ORnet,
StarBridge, and TriChannel are registered trademarks of 3Com
Corporation.
Chipcom OpenHub, G-Man, LANsentry, MultiProbe, ONdemand,
ONline, ONsemble, PowerRing, SL2000, SL3000, SL4000,
StackJack, StackSystem, and SwitchCentral are trademarks of
3Com Corporation.
ii ONline 10BASE-T Security Module Installation and Operation Guide
The Chipcom Multichannel Architecture Communications System is
registered under U.S. Patent Number 5,301,303.
XNS is a trademark and Ethernet is a registered trademark of Xerox
Corporation.
DEC, DECnet, the Digital logo, DELNI, POLYCENTER, VAX, VT100,
and VT220 are trademarks of Digital Equipment Corporation.
UNIX is a registered trademark in the U.S.A. and other countries
licensed exclusively through X/Open Company, Ltd.
IBM is a registered trademark of International Business Machines.
3ComFacts, Ask 3Com, CardFacts, NetFacts, and CardBoard are
service marks of 3Com Corporation.
3Com, LANplex, BoundaryRouting, LanScanner, LinkBuilder,
NETBuilder, NETBuilderII, ParallelTasking, ViewBuilder, EtherDisk,
Etherl\Link, EtherLink Plus, EtherLink II, TokenLink, TokenLink Plus,
and TokenDisk are registered trademarks of 3Com Corporation.
3ComLaser Library, 3TECH, CacheCard, FDDILink, FMS, NetProbe,
SmartAgent, Star-Tek, and Transcend are trademarks of 3Com
Corporation.
CompuServe is a registered trademark of CompuServe, Inc.
3Com registered trademarks are registered in the United States,
and may or may not be registered in other countries. Other brand
and product names may be registered trademarks or trademarks of
their respective holders.
Restricted Rights
Use, duplication, or disclosure b y the G overnm ent is subject to
restrictions as set forth in subparagraph (c)(1) (ii) of the Rights in
Technical Data and Computer Software clause at
DFARS 252.227-7013.
Printed on recycle d paper.
ONline 10BASE-T Security Module Installation and Operation Guide iii
iv ONline 10BASE-T Security Module Installation and Operation Guide
Contents
How to Use This Guide
Audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii
Structure of This Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiv
Docume nt Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv
Related Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvi
3Com Doc uments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xvii
Reference Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xvii
Chapter 1 — Introduction
The ONline 10BA SE-T Secu rity Module . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1
Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2
Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2
ONline Manageme nt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3
Chapter 2 — Designing and Expanding the Network
Understand ing the General Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2
Basic Network Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2
LAN Equivalence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-6
Fibe r Backbone, T wisted P air To-T he-Desk . . . . . . . . . . . . . . . . . . . . . . . . . .2- 7
Fibe r Backbone, T wisted P air To-T he-Desk E xample . . . . . . . . . . . . .2-8
Twisted Pair B ackbone, Twisted Pair To-The-D esk . . . . . . . . . . . . . . . . . . .2-10
Patch Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-11
Redundant Links . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-12
ONline 10BASE-T Security Module Installation and Operation Guide v
Chapter 3 — Installing and Operating the Module
Precautionary Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2
Quick Installation Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2
Unpacking Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4
Setting the Dip Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-5
Inst alling t he Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-8
Inst alling t he Cable Tie-Wra p Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3- 8
Inst alling t he Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-11
Configuring the Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-13
Port Enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-14
Networ k Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-14
Port Redundancy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-14
Link Integrity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-15
Modul e Securit y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-15
Autopartition Threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-16
Savi ng Module Co nfigur ations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-16
Reverting Module Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-16
Showing Module Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-17
Monitoring the Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-18
LED and Network Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-21
Chapter 4 — Configuring Security Features
Quick Reference for Configuring Security . . . . . . . . . . . . . . . . . . . . . . . . . .4-2
Configuring Security Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-4
Eavesdropping Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-4
Intrusion Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-5
Defining Port Secur ity Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-6
Defining Port Action on Intrusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-7
Configuring Autole arning Mask . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-8
Enabling Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-8
Configuring Autole arning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-9
Defining a MAC Ad dress Manu ally . . . . . . . . . . . . . . . . . . . . . . . . . . .4-11
Downloading the Autolearning Database . . . . . . . . . . . . . . . . . . . . . .4-12
Configuring Security Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-13
Saving Security Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-14
Reverting Security Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-14
Showing Security Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-14
vi ONline 10BASE-T Security Module Installation and Operation Guide
Showing Port Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-15
Showing Security Aut olearn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-17
Showing Security Intruder List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-18
Clearing Security Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-19
Clearing the MAC Address Table . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-19
Clearing the Autolearning Database . . . . . . . . . . . . . . . . . . . . . . . . . .4-20
Clearing the Security Intruder List . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-20
Using 3Com MIB Security Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-21
EMM Secu rity SNMP Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-21
Using the Security Module SNMP Variables . . . . . . . . . . . . . . . . . . . . .4-22
Chapter 5 — Troubleshooting
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1
Troubleshooting Using the Status LEDs . . . . . . . . . . . . . . . . . . . . . . . . .5-2
Troubleshooting Using the Activity LEDs . . . . . . . . . . . . . . . . . . . . . . . .5-4
Technical Assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-5
Appendix A — Specifications
Elec trical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A- 1
Environment al Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
Mechanical Specificatio ns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
General Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
50-P in Connec tor and Cab le . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A -3
Twisted Pair C onnect ors and Cabl es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A -6
Twisted Pair C onnect ors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-7
Twisted Pair C ables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-8
ONline 10BASE-T Security Module Installation and Operation Guide vii
Appendix B — Technical Support
On-line Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-1
Email Technical Sup por t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-2
World Wide Web Sit e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-2
Support from Your Network Supplier . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-2
Support from 3Com . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-3
Returning Products for Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-4
Accessing the 3 Com MIB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-4
3Com Tec hnica l Publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-5
Index
viii O Nline 10BASE-T Security Module Installation and Operation Guide
Figures
Figure 1-1. ONline 10BASE-T Security Module Application . . . . . . . . . .1-3
Figure 2-1. Sample Configuration Distance Calculation . . . . . . . . . . . . .2-9
Figure 2-2. Unshielded Twisted Pair Network . . . . . . . . . . . . . . . . . . .2-11
Figure 2-3. Redundant Twisted Pa ir Configu ration . . . . . . . . . . . . . . .2-12
Figure 3-1. Security Module Dip Switch SW1 Location . . . . . . . . . . . . .3-5
Figure 3-2. Attaching the Tie-Wrap Bracket to the Module . . . . . . . . . .3-9
Figure 3-3. Attaching Cables With 90° Connectors . . . . . . . . . . . . . . .3-10
Figure 3-4. Installing an ONline 10BASE-T Security Module . . . . . . . . .3-11
Figure 3-5. ONline 10BASE-T Security Module Cable Connection . . . .3-12
Figure 3-6. Security Module Faceplate . . . . . . . . . . . . . . . . . . . . . . . .3-19
Figure 4-1. Example of Eavesdropping Security . . . . . . . . . . . . . . . . . . .4-5
Figure 4-2. Example of Intrusion Detection . . . . . . . . . . . . . . . . . . . . . .4-6
Figure A-1. 50-Pin Cable Male and Female Connectors . . . . . . . . . . . . A-4
Figure A-2. RJ-45 Connector Pinouts . . . . . . . . . . . . . . . . . . . . . . . . . . A-7
ONline 10BASE-T Security Module Installation and Operation Guide ix
x ONline 10BASE-T Security Module I ns tallation and Operat ion Guide
Tables
Table 2-1. Seven Basic Network Rules . . . . . . . . . . . . . . . . . . . . . . . . .2-3
Table 2-2. LAN Product Equiva lent Distances . . . . . . . . . . . . . . . . . . . .2-6
Table 2-3. Maximum Lin k Distance on Twisted Pair . . . . . . . . . . . . . .2-10
Table 3-1. Procedures for Completing Insta llation . . . . . . . . . . . . . . . .3-2
Table 3-2. DIP Switch S W1 N etwork Se lection Settings . . . . . . . . . . . .3-6
Table 3-3. DIP Switch S W1 Security and Link In tegrity Setti ngs. . . . . . .3-7
Table 3-4. Interpretation of the Security Module LEDs . . . . . . . . . . . .3-20
Table 3-5. Network Check Codes. . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2 1
Table 4-1. Quick Reference for Configuring the Security
Modul e. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-2
Table 5-1. Troubleshooting Using the Port Status LEDs. . . . . . . . . . . . .5-2
Table 5-2. Troubleshooting Using the Activity LEDs . . . . . . . . . . . . . . .5-4
Table A-1. 50-Pin Cable Pinouts and Port Assignments . . . . . . . . . . . . A-5
ONline 10BASE-T Security Module Installation and Operation Guide xi
This guide tells you how to install and operate the 3Com ONline™
10BASE-T Security Module (referred throughout this guide as the Security
Module) for the ONline System Concentrator. A configuration section is
provided to help you plan your network configuration. This guide also
includes information on moni toring the module us ing an ONline network
mana gemen t mod ule . An a pp endi x ex pla ins ca blin g gu idel in es a nd op tion s
for this module.
Audience
This guide is intended for the following people at your site:
How to Use This Guide
❑ Network manager or administrator
❑ Hard ware installer
ONline 10BASE-T Security Module Installation and Operat ion Guide xiii
Structure of This Guide
This guide contains the following chapters:
Chapter 1, Introducti on – Introduces the principal features of the
Security Module.
Chapter 2, Designing and Expanding the Network – Explains
examples of possible network configurations using the ONline System
Concentrator and the Security Module.
Chapt er 3, I n stall ing and Operating the Mod u le – Provides illustrated
procedures for installing the Security Module into the ONline System
Concentrator. Also shows front panel LEDs and the DIP switch on the
module.
Chapter 4, Configuring Security Features – Describes the security
features and provides the management commands to configure these
features. Also provided are the commands to show and clear security
configurations.
Chapter 5, Troubleshooting – Provides help in isolating and correcting
problems that may arise during the installation process and during norma l
operation.
Appendi x A, Spec ificat ions – Provides electrical, environmental, and
mechanical specifications for the Security Module, plus information on the
module's 50-pin Telco connector, RJ-45 connectors, and Twisted Pair cables.
Appendix B, Technical Support – Lists the vario us methods for
contacting the 3Com technical support organization and for accessing
other product support se rvices.
Index
xiv ONline 10BASE-T Security Module Installation and Operation Guide
Document Conve ntions
The following document conventions are used in this manual:
Convention Indicates Example
Courier text User input In the Agent Information Form,
enter MIS in the New Contact
field.
System output After pressing the A pply
button, the sy stem displays
the message
Transmi tt in g da ta .
Bold command
string
Italic text in braces User-substituted
Capitalized text in
plain brackets
Italics Text emphasis,
Path names Before you begin, read the
identifiers
Keyboard entry
by the user
docu me nt title s
readme.txt file located in
/usr/snm/agents.
Use t he following comma nd to
show port detail s:
SHOW PORT {
Type your password and press
[ENTER].
Ensure that you press the Apply
button after you add the new
search parameters.
slot
.all} VERBOSE
ONline 10BASE-T Security Module Installation and Operation Guide xv
Convention Indicates Example
Note: A Note. The
Caution: A Caution. A
Warning: A Warning. A
Related Docu me nts
This section provides information on supporting documentation, including:
❑ 3Com Documents
information is
important
condition may
damage
software or
hardware
condition may
threaten
personal safety
Note: Use STP lobe
cables for yo ur s yste m.
Caution: Do not put
your installation
diskettes on a
magnetic surface.
This may damage the
diskettes.
Warning: We ar eye
protec tion when
performing these
maintenance
procedures.
❑ Reference Do cuments
xvi ONline 10BASE-T Security Module Installation and Operation Guide
3Com Documents
The following documents provide ad ditional information on 3Com
products:
17-Slot ONline System Concentrator Installation and Operation
Guide – Explains how to install, operate, and manage the 3Com ONline
17-Slot Syste m Concentra tor (Models 5017C-LS and 5017 C with load
sharing).
6-Slot ONline System Concentrator Installation and Operation
Guide – Explains how to install, operate, and manage the 3Com ONline
6-Slot System Concentrator.
ONline Ethernet Management Module Installation and Operation Guide –
Describes h ow to install the ONline Ethernet Network Management
Module in the ONline System Concentrato r and explains the LEDs on the
module faceplate. This guide also provides instructions for connecting a
terminal to the module and describes the management commands
necessary to perform management tasks on the concentrator and on
remote devices.
ONline Management Commands Guide – Provides an a lphabetized
reference resource describing all ONline ma nagement commands.
For a complete list of 3Com documents, contact your 3Com representative.
Reference Documents
The following documents supply related background information:
Case, J., Fedor, M., Scoffstall, M., and J. Davin, The Simple Network
Management Protocol, RFC 1157, University of Tennessee at Knoxville,
Performan ce Systems International and the MIT Laboratory for Computer
Science, May 1990.
Rose, M., and K. McCloghrie, Structure and Identification of
Management Information for TCP/IP-based Internets, RFC 1155,
Performance Systems International and Hughes LAN Systems, Ma y 1990.
ONline 10BASE-T Security Module Installation and Operation Guide xvii
Introduction
1
This chapter describes the principle features of the ONline 10BASE-T
Security Module.
The ONline 10BASE-T Security Module
The ONline 10BASE-T Security Module is a 12-port IEEE 802.3 repeater
module that complies with the 10BASE-T standard. The module is designed
for use with the 3Com ONline System Concentrators using unshielded
twisted pair wiring. The Security Module provides the following features
and benefits:
❑ Provides jamming security for 12 10BASE-T ports
❑ Provides security from unauthorized transmissio ns
❑ Uses the 3Com ONgua rd™ technology to secure the network from
eavesdropping and i ntrusions
❑ Suppo rts up to 150 meter link distances on 22 gauge wire and up to
125 meters on 24 ga uge wire (the meter distance on 26 gauge wire
varies by cable type)
❑ Complies fully with the 10BASE-T signaling standard
Introduction 1 - 1
❑ Features 'hot swap' capability so that you can install or remove the
module without having to power d own the conc entrator
In addition, the Security Module allows you to disable Link Integrity, which
allows the module to be connected to equipment that does not conform to
the 10BASE-T standard.
Before installing the Security Module into the ONline System Concentrator,
read the ONline System Concentrator Installation and Operation Guide.
Theory of Operation
The Security Module incorporates repeaters and twisted pair transceivers in
its hardware:
– Repeaters restore phase and frequency. Repeated signals
synchronize to the system clock and enter on the ONline
concentrator's TriChannel™ backplane. Outgoing signals
from the TriChannel backplane are sent directly to
transceive rs to be transmitted to twisted pair link
segments.
– Transceivers receive and restore amplit ude to incom ing
signals.
Application
Attach the Security Module to a pa tch or punchdown block using bundled
25-pair or 12-leg hydra cables. This provides connections for the 12 twisted
pair ports, as shown in Figure 1-1.
1 - 2 ONline 1 0B ASE-T Security Module I ns tallation and Operat ion Guide
Figure 1-1. ONline 10BASE-T Security Module Application
ONline Management
A master ONline Ethernet Management Module (EMM) at Version 4.0 is
capable of managing the Security Module, including the Autolearning
feature.
A master ONline Token Ring Management Module (TR MM) at Version 3.0
is capable of managing the Security Module with the exception of the
Auto learning Feat ure. You must manually add MAC addresses to a port
MAC address table in order for a TRMM to manage the security features of
the Security Module. Refer to Chapter 4 for a description of the commands
to add MAC addresses to a po rt MAC address tab le.
Introduction 1 - 3
2
Designing and Expanding t he Network
This chapter contains configuration information that will help you to design
your netw ork. Install all equ ipment using only approved cables for proper
operation. Refer to Appendix A, Twisted Pair Connectors a nd Cables, for
information on twisted pair connector and cable requirements.
This chapter includes five sections which describe how to configure your
network using the ONline System Concentrator and the ONline 10BASE-T
Security Module. These sections include:
❑ Understanding Network Configurations
❑ Fibe r Backbone, Twisted Pair To-T he-Desk
❑ Twisted Pair Backbone, Twisted Pair To-The-Desk
❑ Patch Panels
❑ Redundant Links
Designing and Expanding the Network 2 - 1
Understanding the General Rule s
As part of your network design, it is important to consider your network
size. For instance, is the network (end-to-end) 100 meters, 1000 meters,
4000 meters, or more? What are your plans for expansion? Your answers
play a role in how you configure your network. For example, once the
network expands beyond a certain size, you need to add a bridge or other
internetworking device.
This section describes general rules for configuring an Ethernet network
using fiber as the backbone medium. It also provides rul es to ensure that
your network configuration conforms to distance limitations imposed by
Ethernet and networking equipment.
This secti on includ es:
❑ Basic Network Rules
❑ LAN Equivalence
Basic Network Rules
This section outlines the basic network rules and 3Com’s recommendations
for these rules. For more hardware-specific information on the 10-Port
module, refer to Appendix A.
2 - 2 ONline 1 0B ASE-T Security Module I ns tallation and Operat ion Guide
Table 2-1 outlines the seven basic rules to keep in mind when you construct
your network.
Table 2-1. Seven Basic Network Rules
Rule Definition Recommendations/Notes
1 If possible, use
10BASE-FB as the
backbone medium.
2 Wire the backbone in
a star topology to
isolate faults.
3 The maximum Fib er
Ethernet network
diameter is 4200
meters of fiber cable.
Use 62.5 micron cable to conform
with the IEEE 10B ASE-F and
upcoming ANSI FDDI standards.
Use ST-type connectors.
Make sure to l ay extra fiber cables.
The extra cost is small and you will
find yo u need th em as your net work
grows.
The st ar to po log y conf or ms t o FDD I
wiring as well -- just make sure to
run at least two fiber strands to
every backbon e co nnection.
The 4200 meters is the maximum
distance between any two
transceivers on the network.
The 4200 meters does not include
the transceiver cable (that is, drop or
patch cable) that connects a device
with an external transceiver.
Transceiver cables can extend up to
50 meters. Thus, total network
diameter can be as much as 4300
meters (420 0 m + 2 * 50 m)
betwee n any two nodes.
Designing and Expanding the Network 2 - 3
Table 2-1. Seven Basic Network Rules (Continued)
Rule Definition Recommendations/Notes
4 Certain LAN devices
on the network shrink
the maximum Fiber
Ethernet network
diameter to less than
4200 meters.
5 Assume that one
meter of co axial or
twisted pair is equal to
one meter of fib er
cable.
Many LAN pro du cts de la y th e si gna l
that goes through them. This is
known a s equivalent distance. Ev ery
microsecond delay reduces the
maximum link distance. In fact,
every microsecond delay shrinks the
network diameter by approximately
200 meters of fiber cable. Table 2-2
lists the Equivalent Distances for
other 3Com products.
This is a conservative rule. For
example, the actual equivalence is
about 1.1 meters of coaxial for
every meter of fiber. For simplicity,
assume one meter.
2 - 4 ONline 1 0B ASE-T Security Module I ns tallation and Operat ion Guide
Table 2-1. Seven Basic Network Rules (Continued)
Rule Definition Recommendations/Notes
6 The f iber l ink dist ances
must not exceed the
limits imposed by the
optical power budget.
7 When in doubt, use a
bridge.
In general, on 62.5 micron cable,
you can go up to 4000 meters
point-to-point using the ONcore or
ONline Fiber Mo dules. If you ha ve
poor quality cable or cross many
patch panels, you may have to
sacrifice some distance.
Some older Eth ernet fiber optic
products are less powerful than
ONcore Fiber Module optic s. So
when connecting to these products,
remember that the least powerful
device determines the maximum
point-to-point distan ce.
If you are not certain if you have
exceeded allowable network
distances, use a bridge to extend
the network.
Designing and Expanding the Network 2 - 5
LAN Equivalence
LAN equivalen ce is the sum of both the incoming and outgoing module
port signals . Different modules, however, have different equivalent
distances. Table 2-2 lists the LAN product equivalent distances..
Table 2-2. LAN Product Equivalent Distances
LAN Produc t
ONline 10BASE-T Security Module (5112M-TPLS) 585
Incoming si gnal to TP port 420
Outgoing signal from TP port 165
ONline Ethernet 10BASE-FB Modules (5104M-FB,
5102M-FBP, 5104M-FBP)
Incoming signal to fiber port 140
Outgoing signal from fibe r por t 50
ONline Ethernet FOIRL Module (510 4M-FL) 560
Incoming signal to fiber port 330
Outgoing sign al from fibe r por t 230
ONline Ethernet 10BAS E-T Module (5108M-TP) 585
Incoming si gnal to TP port 420
Outgoing signal from TP port 165
Equivalent Fiber
Distance (meters)
190
ONline Ethernet 50-Pin Module
(5112M-TPL,
5112M-TPPL)
Incoming si gnal to TP port 420
Outgoing signal from TP port 165
2 - 6 ONline 1 0B ASE-T Security Module I ns tallation and Operat ion Guide
585
Table 2-2. LAN Product Equivalent Distances (Continued)
LAN Produc t
ONline Ethernet 24-Port Module (5124M-TPCL) 585
Incoming si gnal to TP port 420
Outgoing signal from TP port 165
ONline Ethernet Repeater Module (5102M-AUIF) 800
Incoming si gnal to AUI port 600
Outgoing signal from AUI port 200
ONline Ethernet BNC Module (5106M-BNC) 900
Incoming signal to BNC port 450
Outgoing signal from BNC port 450
ONline Ethernet Transceiver Module
(5103M-AUIM)
3Com 10BASE-FB Star Coupler (9308S-FB) 180
ORnet Star Coupler (9314S) 180
Equivalent Fiber
Distance (meters)
0
IEEE Repeater 800
Fiber Backbone, Twist ed P air To-T h e-D esk
When you configure a network with unshielded twisted pair cabling
to-the-desk and fiber for the backbone, be aware of the following:
Designing and Expanding the Network 2 - 7
❑ You must add a bridge if you exceed four full repeaters. The
four-repeater rule for Ethernet limits the number of 10BASE-T
modules between any two transceivers. When traffic goes into a port
on any repeater-based module and out the backplane, it counts as a
1/2 repeater. When the traffic goes into the module thro ugh one
port and out another port on the same or a different module, it
counts as one full repeater. Therefore, you must add a bridge if the
path from one transceiver to another exceeds the four-repeater rule.
❑ The equivalent fiber distance fo r the ONline Ethernet Fiber Modules
(se e Rule 4) is:
– 140 meters for signals that externally enter a Fiber Module
port
– 50 meters for signals that internally enter a Fiber Module
through the ONline Concentrator backplane
❑ The equivalent fiber distance for the Security Module (see Rule 4) is:
– 420 meters for signals that externally enter a Security
Module
– 165 meters for signals that internally enter a Security
Module through the ONline System Concentrator
backplane
For every pair of Security Modules that a signal goes through, deduct a
fiber equivalent distance of 585 meters (420 m + 165 m = 585 m) from the
overall alllowable network diameter. This is also true if a signal makes a
roundtrip through a single Security Module (enters the Security Mo dule
through one port and exits another port of the same Security Module). This
counts as 585 meters of fiber equivalent distance, and as a full repeater.
Fiber Backbone, Twisted Pair To-The-Desk Example
In the sample configuration shown in Figure 2-1, we determine if the
transceivers are within legal Ethernet limits. 22-gauge unshielded twisted
pair cable is used to connect 10BASE-T Transceivers to the Security Modules
in the concentrators.
2 - 8 ONline 1 0B ASE-T Security Module I ns tallation and Operat ion Guide
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