3COM 6416SW User Manual

ONcore ATM Switch/Control Module

Installation and User's Guide

Document Number: 17-00616-3

Printed March 1996

Model Number: 6416SW

3Com Corporation

118 Turnpike Road

Southborough, MA 01772-1886

U.S.A.

[phone]

FAX: [phone]

Federal Communication 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 the user will be required to correct the interference at his own
expense.

Canadian Emission Requirements

Cet appareil numérique respecte les limites de bruits radioélectriques
applicables aux appareils numériques de class A prescrites dans la norme
sur le materiel brouilleur: "Appareils Numériques", NMB-003 édictée par le
ministre des Communications.

This digital apparatus does not exceed the Class A limits for radio noise
emissions from digital apparatus set out in the Interference-causing
equipment standard entitled "Digital Apparatus", ICES-003 of the
Department of Communications.

VDE Class B Compliance

Hiermit wird bescheinigt, class der (6416SW) in Uebereinstimmung mit den
Bestimmungen der Vfg 243/1991 funkentstoert ist.

Der Deutschen Bundespost wurde das Inverkehrbringen dieses Geraetes
angezeigt und die berechtigung zur Ueberpruefung der Serie auf
Einhaltung der bestimmungen eingeraeumt.

Einhaltung mit betreffenden Bestimmugen kommt darauf an, dass
geschirmte Ausfuehrungen gebraucht werden. Fuer die Beschaffung
richtiger Ausfuehrungen ist der Betreiber verantwortlich.

ii ONcore ATM Switch/Control Module: Installation and User's Guide

This is to certify that the (6416SW) 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 reponsible for procuring the appropriate cables.

VCCI Class 1 Compliance

This equipment is in the 1st Class category (information equipment to be
used in commercial and/or industrial areas) and conforms to the standards
set by the Voluntary Control Council For Interference by Data Processing
Equipment and Electronic Office Machines aimed at preventing radio
interference in commercial and/or industrial areas.

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

Read the instructions for correct handling.

iii

Fiber Cable Classification

Use this equipment only with fiber cable classified by Underwriters
Laboratories as to fire and smoke characteristics in accordance with
section 770-2(b) and Section 725-2(b) of the National Electrical Code.

UK General Approval Statement

The ONline System Concentrator and the ONcore Switching Hub are
manufactured to the International Safety Standard EN 60950 and as such
are approved in the UK under the General Approval number
NS/G/12345/J/100003 for indirect connection to the public
telecommunication 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 Statement

1995, 1996 by 3Com Corporation. All rights reserved. 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 trademarks by the companies that manufacture the
products. It is not our intent to claim these names or trademarks as our
own.

ONdemand and TriChannel are trademarks, and 3Com, CELLplex, and
ONcore registered trademarks, of 3Com Corporation.

iv ONcore ATM Switch/Control Module: Installation and User's Guide

The following terms are trademarks or service marks of the IBM
Corporation in the United States or other countries: AIX, AIXwindows, IBM,
NetView for AIX, Nways and RISC System 6000.

XNS is a trademark and Ethernet is a registered trademark of Xerox
Corporation.

v

vi ONcore ATM Switch/Control Module: Installation and User's Guide

Contents

Chapter 1. Introduction to ATM ..................... 1-1

3Com ONcore ATM Subsystem ...................... 1-2

ATM Backplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

ATM Switch/Control Module ....................... 1-6

ATM Subsystem Traffic Management ................ 1-11

ATM Subsystem Chassis Management ............... 1-12

Benefits of Using ATM in the ONcore Hub ............. 1-14

LAN Emulation Client (LEC) ....................... 1-15

Chapter 2. Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Before You Start ............................... 2-1

Unpacking the Module ............................ 2-2

Installing the 6416SW Module ....................... 2-3

Verifying Normal 6416SW Operation ................... 2-7

Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

Meaning of the LEDs .......................... 2-10

ATM Reset Button ............................ 2-12

RS-232 Console Port .......................... 2-13

RS-232 Auxiliary Port .......................... 2-14

Chapter 3. ATM Addressing . . . . . . . . . . . . . . . . . . . . . . . 3-1

ATM Campus Networks ........................... 3-1

Network Components . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

Network Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6

Defining the ATM Address of the 6416SW ................ 3-7

Setting-Up ATM Trunk Connections .................... 3-8

Using Static Routes ............................ 3-9

Trunks Within a Single Cluster/Subnetwork .............. 3-9

Trunks Between Subnetworks ..................... 3-10

Example: Configuring a Connection Between User Devices ... 3-11

Using Permanent Virtual Connections .................. 3-13

Chapter 4. Setting-Up and Using a Configuration Console .... 4-1

Contents vii

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Before You Start ............................... 4-3

Entering 6416SW Commands ...................... 4-3

Keyboard Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Getting Help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

Command Completion . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

Setting Up a Configuration Console in Normal (ASCII) Mode ..... 4-7

Setting Up a Configuration Console in SLIP Mode ........... 4-8

Returning to Normal Mode ........................ 4-9

SLIP Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10

TELNET Sessions Via a Remote Switch ................ 4-12

Minimum Local Configuration ..................... 4-12

Logon Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13

Reconfiguring 6416SW Configuration Console Settings ........ 4-15

Saving Reconfigured Configuration Console Settings ....... 4-15

Automatic Modem Hangup ....................... 4-16

Chapter 5. Configuring the ATM Switch/Control Module ...... 5-1

Configuration Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

Setting 6416SW Passwords ......................... 5-6

Administrator Password . . . . . . . . . . . . . . . . . . . . . . . . . 5-6

User Passwords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8

Setting the Internal Clock .......................... 5-9

Setting Local 6416SW Parameters .................... 5-10

Switch Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10

Service Contact Information ...................... 5-11

Console Prompt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11

Console Timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12

Setting the ATM Address of the 6416SW ................ 5-13

Connecting ATM media Modules ..................... 5-14

Enabling ATM Ports and Interfaces ................... 5-15

Disabling an ATM Port ......................... 5-15

Setting Up Trunks (Logical Links) .................... 5-16

Static Routes for Other Subnetworks ................. 5-16

Setting SNMP Parameters ........................ 5-17

IP Address and Subnetwork Mask (IP only) ............. 5-18

LAN Emulation Client (LE only) .................... 5-19

viii ONcore ATM Switch/Control Module: Installation and User's Guide

Default Gateway (IP & LE) ....................... 5-21

ARP Server (IP only) .......................... 5-21

Community Table (IP & LE) ...................... 5-22

Alerts (IP & LE) ............................. 5-22

Setting the LECS ATM Address ..................... 5-23

Saving Configuration Settings and Logging Off ............ 5-25

Working With Configuration Settings ................... 5-28

Reverting Configuration Changes ................... 5-28

Displaying Configuration Settings ................... 5-29

Modifying Configuration Settings ................... 5-32

Isolating and Reconnecting ATM Media Modules ........... 5-33

Fault Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-33

Chapter 6. Network and Switch Management ............ 6-1

Managing the ATM Subsystem ....................... 6-1

SNMP Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2

Accessing MIB Files ........................... 6-3

Security Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4

Uploading and Downloading Operations ................. 6-5

Inband Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6

Out-of-band Operations . . . . . . . . . . . . . . . . . . . . . . . . . 6-9

Chapter 7. Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . 7-1

Phase 1: Installation and Power Problems ................ 7-2

Prerequisites for ATM Troubleshooting ................. 7-3

Diagnosing Problems from the ATM Media LEDs .......... 7-4

Diagnosing Problems from the 6416SW LEDs ............ 7-6

Diagnosing Problems with the Power Supply ............. 7-9

Phase 2: Problems During ATM Configuration ............ 7-10

Diagnosing Problems Concerning the 6416SW Console ...... 7-11

Diagnosing Problems with ATM Modules .............. 7-14

Diagnosing Problems with ATM Ports ................ 7-15

Phase 3: Problems on ATM Media Ports Without ATM Traffic ... 7-19

Diagnosing Problems with ATM Ports Attached to ATM Devices . 7-20

Checking ATM Address Registration ................. 7-22

Diagnosing Problems in the Hardware Configuration ........ 7-23

Phase 4: Problems with Normal ATM Operation ........... 7-24

Contents ix

ONcore Cannot PING the ARP Servers and Vice-versa ...... 7-25

ONcore Hub Cannot PING an ARP Client .............. 7-27

ONcore LEC Cannot PING another Client and Vice-versa .... 7-28

ARP Client Cannot PING the ARP Server .............. 7-29

Two Devices Using IP Over a PVC Cannot Ping Each Other ... 7-30

ONcore LEC Cannot Initialize to the LES/BUS ........... 7-31

Administrative Problems (Netview/SNMP/Telnet) .......... 7-34

Communication Problems in an IBM LAN Emulation Environment 7-39

Other Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-44

ATM Connection Problems ....................... 7-47

Using 6416SW Trap Messages ...................... 7-50

Contacting Your 3Com Service Representative ............ 7-51

Troubleshooting Phase 1 and Phase 2 Problems .......... 7-51

Troubleshooting Phase 3 Problems .................. 7-52

Troubleshooting Phase 4 Problems .................. 7-53

Appendix A. Technical Specifications . . . . . . . . . . . . . . . . . A-1

General Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2

Environmental Specifications . . . . . . . . . . . . . . . . . . . . . . . . A-2

Mechanical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . A-2

Appendix B. RS-232 Cable and Modem Requirements ....... B-1

Attaching a Console, Modem, or Server .................. B-1

RS-232 Cable Requirements ........................ B-2

RS-232 Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2

9-Pin/9-Pin Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-3

9-Pin/25-Pin Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-4

Null-Modem Interposer . . . . . . . . . . . . . . . . . . . . . . . . . . B-5

Modem Attachment . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-6

Modem Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-7

Modem Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-7

Appendix C. Error and Information Codes .............. C-1

Q.2931 Error Codes for Clear Causes ................... C-2

Maintenance Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-5

IBM LAN Emulation Server Error Codes ................. C-6

x ONcore ATM Switch/Control Module: Installation and User's Guide

Appendix D. Configuring AIX for Download and Upload

Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1

Appendix E. ONcore ATM Address Formats ............. E-1

Network Prefix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-3

End System Part ............................. E-5

Appendix F. Technical Support . . . . . . . . . . . . . . . . . . . . . F-1

Online Technical Support .......................... F-2

E-mail Technical Support ......................... F-2

World Wide Web Site ........................... F-2

Support from Your Network Supplier .................... F-3

Support from 3Com ............................. F-4

Returning Products for Repair ....................... F-5

Accessing the 3Com MIB and atswitch.mib ................ F-6

3Com Technical Publications ........................ F-6

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . X-1

Contents xi

xii ONcore ATM Switch/Control Module: Installation and User's Guide

Figures

1-1. ATM Backplane in the 17-slot 3Com ONcore Hub ...... 1-3

1-2. Wiring Star Topology in ATM Backplane (17-slot model) ... 1-4

2-1. Installing the 6416SW Module in an ONcore Hub ....... 2-3

2-2. ONcore Module Ejectors ..................... 2-4

2-3. Attaching a Terminal to the 6416SW RS-232 Console Port . 2-6

2-4. Front Panel of 6416SW Module ................. 2-9

3-1. Components of an ATM Campus Network ........... 3-2

3-2. ATM Address Hierarchy ...................... 3-3

3-3. ATM Logical Links Used to Connect ATM Clusters ...... 3-8

3-4. Using Static Route Mappings to Connect User Devices

Across Subnetworks . . . . . . . . . . . . . . . . . . . . . . . 3-12

4-1. Working in Remote 6416SW Sessions ............ 4-14

6-1. Upgrade Operations for ATM Microcode ............ 6-5

B-1. RS-232 Connector . . . . . . . . . . . . . . . . . . . . . . . . . B-2

B-2. Console Attachment: 9-pin to 9-pin RS-232 Cable ...... B-3

B-3. Console Attachment: 9-pin to 25-pin RS-232 Cable ...... B-4

B-4. Pin Assignment: RS-232 Interposer ............... B-5

B-5. Pin Assignment: RS-232 Modem Cable ............ B-6

B-6. Example: IBM 7855-10 Modem Configuration ......... B-8

E-1. NSAP Address Formats Supported in the ONcore ATM

Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-2

Figures xiii

xiv ONcore ATM Switch/Control Module: Installation and User's Guide

Tables

1-1. ATM Connections Supported in ONcore Hubs ......... 1-7

1-2. Maximum PING and TELNET Message Lengths ...... 1-15

2-1. Meaning of the 6416SW LEDs ................. 2-10

2-2. RS-232 Console Port Pin Assignments (DB9) ........ 2-13

2-3. RS-232 Auxiliary Port Pin Assignments ............ 2-14

5-1. 6416SW Configuration Commands ............... 5-4

7-1. 6416SW Trap Messages .................... 7-50

B-1. EIA 232 Connector-Pin Signal Assignments .......... B-2

C-1. Q.2931 Error Codes for Clear Causes in ONcore-based ATM

Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-2

C-2. Maintenance Codes and Meanings ............... C-5

C-3. IBM LAN Emulation Server Error Codes ............ C-6

Tables xv

xvi ONcore ATM Switch/Control Module: Installation and User's Guide

How to Use This Guide

This guide presents information on how to install and configure the 3Com
ONcore ATM Switch/Control Module (Model Number 6414SW) in the
3Com ONcore Switching Hub. It describes how to diagnose and solve
problems associated with the operation of the 6416SW module, and
describes some of the principles of asynchronous transfer mode (ATM)
technology on which the 6416SW module is based.

This guide also describes how to install and configure a management
console for the 6416SW module. The ATM commands that you enter at
the console to manage the ATM subsystem in the ONcore hub are
described in the

ATM Command Reference Guide

ONcore Switching Hub, CELLplex 4000 Workgroup Switch

, Document Number: 17-00866.

,

Who Should Use this Guide

This guide is intended for the following people at your site:

ATM network administrator
ATM network operator

Hardware installer.

How to Use this Guide

This guide contains seven chapters and six appendixes:

Chapter 1, “Introduction to ATM” gives an overview of the main
functions of the 6416SW module.

Chapter 2, “Installation” describes how to install the 6416SW module in
the ONcore hub. It also describes how to connect a console to the
6416SW module in order to perform configuration tasks.

How to Use This Guide xvii

Chapter 3, “ATM Addressing” describes the components of an ATM
Campus network, guidelines for defining ATM addresses for the 6416SW,
how to set up trunk connections within and between networks, and how to
use Permanent Virtual Connections (PVCs). It also describes how to
connect a console to the 6416SW module in order to perform configuration
tasks.

Chapter 4, “Setting-Up and Using a Configuration Console” describes
how to set up and configure the 6416SW management console, set an
ATM address, and configure facilities for SNMP management and remote
login.

Chapter 5, “Configuring the ATM Switch/Control Module” describes
how to configure the 6416SW module after installing it in the ONcore hub.

Chapter 6, “Network and Switch Management” provides guidelines for
managing and maintaining the ATM Switch/Control.

Chapter 7, “Troubleshooting” describes how to diagnose and solve
problems associated with the installation and operation of the 6416SW
module, 6416SW console, and ATM subsystem in the ONcore hub.

Appendix A, “Technical Specifications” describes the technical
specifications for the 6416SW module.

Appendix B, “RS-232 Cable and Modem Requirements” describes the
RS-232 cable requirements and pin assignments for connecting a console
or modem to the 6416SW module's RS-232 Console port. It also describes
how to configure a modem connection.

Appendix C, “Error and Information Codes” describes the return codes
displayed for the Q.2931 protocol and Maintenance mode.

Appendix D, “Configuring AIX for Download and Upload Operations”

describes how to configure a server running AIX* for TFTP file transfers
with ATM ONcore hubs.

xviii ONcore ATM Switch/Control Module: Installation and User's Guide

Appendix E, “ONcore ATM Address Formats” describes the ATM
addressing formats.

Appendix F, “Technical Support” describes the support services
provided by 3Com Corporation.

How to Use This Guide xix

Prerequisite Knowledge

To understand the information presented in this guide you should be
familiar with:

Features and characteristics of the 3Com ONcore Switching hub, as

described in

Guide

Principles of asynchronous transfer mode (ATM) technology
ATM Forum UNI Specifications V3.0 and V3.1.
ATM Forum LAN Emulation Specifications V1.0.

3Com ONcore Switching Hub Installation and Operation

, 17-00362.

xx ONcore ATM Switch/Control Module: Installation and User's Guide

Conventions Used in This Guide

The following text conventions are used in this guide:

Text
Convention

Bold Text emphasis Selective backpressure temporarily

Italics

Meaning Example

stops one virtual connection.
Global backpressure temporarily

stops an ATM link.
Special term This is known as a
Document titles Refer to the

ATM User-Network

hot swap

.

Interface Specification - Version 3.0

for more information.

Monospace Command syntax

(parameters and
variables)

User input
(including
carriage return)

System
messages and
screen displays

SET PORT slot.port ENABLE

To display detailed information,

enter the following command:

show port 4.2 verbose [ENTER]

Port display for ONcore ATM 155

Mbps Module:

Port Type Mode Status

---------------------------------------------

4. 2 NNI enabled UP-OKAY

How to Use This Guide xxi

Related Documents

This section provides information on supporting documentation, including:
3Com Documents
Reference Documents

3Com Documents

The following documents provide additional information on 3Com products:

ONcore Switching Hub Installation and Operation Guide

provides information on the installation, operation, and configuration of the
ONcore Switching Hub. This guide also describes the principal features of
the ONcore Fault-Tolerant Controller Module.

ONcore Distributed Management Module User's Guide

information on the ONcore Distributed Management Module's operation,
installation, and configuration. This guide also describes the software
commands associated with the Distributed Management Module.

Distributed Management Module Commands Guide

each management command by providing detailed information on the
command's format, use, and description.

ONcore Switching Hub/Cellplex 4000 Workgroup Switch ATM Command
Reference Guide

detailed information on the command's format, use, and description.

For a complete list of 3Com documents, contact your 3Com representative.

17-00866 - describes each ATM command by providing

17-00362 -

17-00370 - provides

17-00372 - describes

xxii ONcore ATM Switch/Control Module: Installation and User's Guide

Reference Documents

The following documents supply related background information:

Case, J., Fedor, M., Scoffstall, M., and J. Davin,

Management Protocol,

Performance Systems International and the MIT Laboratory for Computer
Science, May 1990.

Rose, M., and K. McCloghrie,

Information for TCP/IP-based internets,

International and Hughes LAN Systems, May 1990.

RFC 1157, University of Tennessee at Knoxville,

Structure and Identification of Management

RFC 1155, Performance Systems

The Simple Network

How to Use This Guide xxiii

Service and Support

3Com Corporation is committed to providing our customers with a full range
of support services to provide maximum network uptime.

This section describes:
Warranty Information

Software Subscription Service

Support

Warranty Information

3Com products are covered under a limited factory warranty. This
warrranty covers defects in the hardware, software, or firmware. Hardware
and firmware is covered for one year and software is covered for 45 days.

Software Subscription Service

Software Subscription Service (SSS) is available from 3Com Corporation at
additional cost. SSS provides you with all software upgrades for a one
year period for that product. For example, if you purchase version 1.0 of a
product and you purchase SSS at that time, you will be entitled to all
software releases for that product for one year. This includes all major
releases and all minor releases.

To order SSS, call 3Com Corporation in the U.S. at 800-228-6840 or
508-490-5858 and ask for the SSS Coordinator. You can also send a FAX
to the SSS coordinator at 508-460-6195. When signing up for SSS, be
prepared to provide the following information:

Ship to address
Bill to address
Product serial numbers
Current software version
Original purchase order

xxiv ONcore ATM Switch/Control Module: Installation and User's Guide

Note: You can buy SSS for less that a full year period so that all
software products have the same renewal date for your convenience.

Support

3Com Corporation supports product-related questions through the
Customer Support Organization (CSO). CSO is available Monday through
Friday from 8:30 am to 8:00 pm, Eastern Time. Technical Support
Engineers are available to help diagnose and solve customer problems.
Ensure that you have your product serial number and software revision
level (if applicable) when you call CSO.

If you have a critical problem with your 3Com product and need to return it,
call the Customer Support Organization for a Return Authorization Number
at 800-228-6840 or 508-490-5858.

3Com User Group

The 3Com User Group is a network of global users working with 3Com
toward the common goal of achieving world-class networking solutions.

To join the 3Com User Group or to receive user group information, call one
of the following:

Your local 3Com office

[phone]

[phone] extension 3322

3Com Technical Publications

If you have comments or questions on 3Com Technical Publications
documents, please complete the reader comment form at the back of this
manual or contact the Technical Publications group at one of the following:

On the Internet: [e-mail]

By fax: [phone]

How to Use This Guide xxv

xxvi ONcore ATM Switch/Control Module: Installation and User's Guide

Chapter 1. Introduction to
ATM

This chapter presents an overview of the main principles and modes of operation of
asynchronous transfer mode (ATM) technology on which the 3Com ONcore ATM
Switch/Control (6416SW) module is based. It also describes how ATM is implemented
in the 3Com ONcore Switching Hub and shows how an ONcore-based ATM campus
network can be built by interconnecting ATM subsystems.

1-1

3Com ONcore ATM Subsystem

By interconnecting 3Com ONcore Switching hubs, you can build a private campus
network that uses ATM to provide:

The backbone structure, with possible extensions to the WAN
New LAN capability for attaching workstations and servers with dedicated bandwidth

and isochronous transmission.

ATM is implemented in the ONcore hub to permit existing LANs (such as Token-Ring)
to coexist with the new ATM technology.

In the 3Com ONcore hub, the ATM subsystem consists of the following components:

An ATM backplane for interconnecting active ATM modules installed in any of the

slots in the hub

A 2-slot ATM Switch/Contol Module (6416SW) module (two may be installed in

17-slot models)

ATM media (for example, 100 Mbps Concentration) modules.

1-2 ONcore ATM Switch/Control Module: Installation and User's Guide

ATM Backplane

All data transmitted between modules in the ATM subsystem passes through the ATM
backplane. Data is switched between ATM media modules in the ATM subsystem by a
6416SW module. 6416SW modules are installed in slot positions 9 and 10 in the ATM
backplane of 10-slot models, and slot positions 9 and 10 and/or 11 and 12 in the ATM
backplane of 17-slot models. These positions are shown in Figure 1-1.

Fan Area

17

ATM
Backplane

ShuntBus

Ring-Bus
Connectors

Media
Backplane

TriChannel

TriChannel
Connectors

112233445566778899101011111212131314141515161617

Power
Module

Power
Module

Power
Module

Power
Module

Controller 2
Controller 1

ac Inlets

Figure 1-1. ATM Backplane in the 17-slot 3Com ONcore Hub

Two 6416SW modules may be installed in the 17-slot models. This allows for 6416SW
redundancy (see page “ATM Switch/Control Redundancy” on page 1-13).

1-3

The major difference between the ATM backplane and other ONcore hub LAN
backplanes is that each ATM media module has a dedicated set of connections to the
6416SW module. This set of dedicated connections constitutes a wiring star topology in
which ATM media modules are at the tips of the star and the 6416SW module is at the
center. The wiring topology used in the ATM backplane is shown in Figure 1-2.

Slot Positions for

Fan Area

1 2 3 4 5 6 7 8 9 10 1112 13 14 15 16 17

6416SW Modules:
9 to 10 and 11 to 12

Slot Positions for
ATM Media Modules:
1 to 8 and 12 to 17

ATM Bus Linking
6416SW Modules

6416SW = ATM Switch/Control

Figure 1-2. Wiring Star Topology in ATM Backplane (17-slot model)

1-4 ONcore ATM Switch/Control Module: Installation and User's Guide