Cabletron Systems Switch BRIM A6 User Manual

BRIM-A6  
USER’S GUIDE  
 
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  
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.  
VCCI NOTICE  
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 Information Technology Equipment (VCCI) 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 radios and TV receivers, etc.  
Read the instructions for correct handling.  
ii  
BRIM-A6 User’s Guide  
 
Notice  
CABLETRON SYSTEMS, INC. PROGRAM LICENSE AGREEMENT  
IMPORTANT: Before utilizing 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.  
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.  
3.  
OTHER RESTRICTIONS. You may not reverse engineer, decompile, or disassemble the  
Program.  
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.  
EXCLUSION OF WARRANTY AND DISCLAIMER OF LIABILITY  
1.  
EXCLUSION OF WARRANTY. Except as may be specifically provided by Cabletron in  
writing, Cabletron makes no warranty, expressed or implied, concerning the Program (including  
its documentation and media).  
CABLETRON DISCLAIMS ALL WARRANTIES, OTHER THAN THOSE SUPPLIED TO  
YOU BY CABLETRON IN WRITING, EITHER EXPRESSED OR IMPLIED, INCLUDING  
BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY 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. IN NO EVENT 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 WARRANTIES, IN SOME  
INSTANCES THE ABOVE LIMITATIONS AND EXCLUSIONS MAY NOT APPLY TO  
YOU.  
BRIM-A6 User’s Guide  
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 03867-0505.  
iv  
BRIM-A6 User’s Guide  
 
Notice  
DECLARATION OF CONFORMITY  
Application of Council Directive(s): 89/336/EEC  
73/23/EEC  
Manufacturer’s Name:  
Manufacturer’s Address:  
Cabletron Systems, Inc.  
35 Industrial Way  
PO Box 5005  
Rochester, NH 03867  
European Representative Name:  
European Representative Address:  
Mr. J. Solari  
Cabletron Systems Limited  
Nexus House, Newbury Business Park  
London Road, Newbury  
Berkshire RG13 2PZ, England  
Conformance to Directive(s)/Product Standards: EC Directive 89/336/EEC  
EC Directive 73/23/EEC  
EN55022  
EN 50082-1  
EN 60950  
Equipment Type/Environment: Networking Equipment, for use in a Commercial or Light  
Industrial Environment.  
We the undersigned, hereby declare that the equipment packaged with this notice conforms to the  
above directives.  
Manufacturer  
Legal Representative in Europe  
Mr. Richard Michaud  
Mr. J. Solari  
___________________________________  
Full Name  
___________________________________  
Full Name  
Manager of Engineering Services  
Managing Director - E.M.E.A.  
___________________________________  
___________________________________  
Title  
Title  
Rochester, NH, USA  
Newbury, Berkshire, England  
___________________________________  
___________________________________  
Location  
Location  
BRIM-A6 User’s Guide  
v
 
CONTENTS  
CHAPTER 1  
INTRODUCTION  
1.1 Using This Manual....................................................................... 1-1  
1.2 Document Conventions ............................................................... 1-2  
1.3 BRIM-A6 Overview...................................................................... 1-3  
1.4 BRIM-A6 Features....................................................................... 1-3  
1.5 BRIM-A6 Specifications............................................................... 1-4  
1.6 Related Manuals.......................................................................... 1-4  
1.7 Getting Help................................................................................. 1-5  
CHAPTER 2  
INSTALLATION  
2.1 Unpacking the BRIM.................................................................... 2-1  
2.2 Installing APIMs........................................................................... 2-2  
2.3 Installing BRIMs........................................................................... 2-3  
2.3.1 Installing a BRIM in a MIM.............................................. 2-3  
2.3.2 Installing a BRIM in a Hub .............................................. 2-5  
CHAPTER 3  
LOCAL MANAGEMENT  
3.1 Local Management Keyboard Conventions................................. 3-2  
3.2 Using LIM to create PVCs ........................................................... 3-3  
3.2.1 ATM Connection Tables Screen Fields .......................... 3-4  
3.2.2 ATM Connection Tables Screen Commands ................. 3-5  
3.2.3 Using ATM Connection Tables Screen Commands ....... 3-5  
3.2.4 Adding PVCs to the Connection Tables Screen............. 3-6  
3.2.5 Deleting PVCs from the Connection Tables Screen....... 3-6  
3.3 Using LM to Create PVCs ........................................................... 3-7  
3.3.1 BRIM-A6 Setup Screen Fields........................................ 3-8  
3.3.2 BRIM-A6 Setup Screen Commands............................... 3-9  
3.3.3 Using BRIM-A6 Setup Screen Commands................... 3-10  
3.3.4 Accessing the BRIM-A6 Add/Delete Entry Screen ....... 3-10  
3.3.5 BRIM-A6 Add/Delete Entry Screen Fields.................... 3-11  
3.3.6 BRIM-A6 Add/Delete Entry Screen Commands ........... 3-12  
3.3.7 Adding a PVC ............................................................... 3-12  
3.3.8 Modifying a PVC........................................................... 3-13  
3.3.9 Deleting a PVC ............................................................. 3-14  
CHAPTER 4  
LANVIEW LEDs  
4.1 BRIM-A6 LEDs ............................................................................ 4-1  
4.2 APIM LEDs.................................................................................. 4-2  
BRIM-A6 User’s Guide  
vii  
 
Contents  
APPENDIX A APIM SPECIFICATIONS  
A.1 APIM-11 Specifications............................................................... A-1  
A.2 APIM-21 Specifications............................................................... A-1  
A.3 APIM-22 Specifications............................................................... A-2  
A.4 APIM-29 Specifications............................................................... A-2  
A.5 APIM-67 Specifications............................................................... A-3  
APPENDIX B ATM OVERVIEW  
B.1 ATM Basics................................................................................. B-1  
B.2 The ATM Cell.............................................................................. B-2  
B.3 The ATM Network....................................................................... B-4  
B.3.1 Virtual Channels and Virtual Paths................................. B-4  
B.3.2 Permanent and Switched Virtual Channels .................... B-5  
B.4 ATM Protocol .............................................................................. B-5  
viii  
BRIM-A6 User’s Guide  
 
CHAPTER 1  
INTRODUCTION  
Welcome to the Cabletron Systems BRIM-A6 User’s Guide. This  
manual provides the following information:  
Describes BRIM-A6 features  
Explains how to install the BRIM-A6 in a Cabletron Systems Media  
Interface Module (MIM) or standalone hub  
Outlines specifications for the Cabletron Systems Asynchronous  
Transfer Mode (ATM) Bridge/Router Interface Module (BRIM)  
The BRIM-A6 provides additional connectivity/functionality to various  
Cabletron Systems MIMs and standalone hubs.You should have a general  
working knowledge of ATM networks and the ATM User-Network  
Interface Specification, as proposed in the ATM Forum, prior to installing  
the BRIM-A6. If you need a basic overview of ATM, refer to Appendix B,  
ATM Overview.  
1.1 USING THIS MANUAL  
Read through this manual completely to familiarize yourself with its  
content and to gain an understanding of the features and capabilities of  
the BRIM-A6. The following list provides an overview of each section of  
this manual:  
Chapter 1, Introduction, outlines the contents of this manual, describes  
BRIM-A6 features and concludes with a list of related manuals.  
Chapter 2, Installation, describes how to install ATM Port Interface  
Modules (APIMs) into the BRIM-A6. This chapter also explains how to  
install a BRIM-A6 into a MIM or a standalone hub.  
Chapter 3, Local Management, describes how to create Permanent  
Virtual Connection using Cabletron Systems Local Interface Management  
(LIM) or Cabletron Systems Local Management (LM).  
Chapter 4, LANVIEW LEDS, describes how to use the BRIM-A6 LEDs  
to monitor BRIM performance and status.  
BRIM-A6 User’s Guide  
Page 1-1  
 
Chapter 1: Introduction  
Appendix A, APIM Specifications, describes specifications and features  
for each of the APIMs available for the BRIM-A6.  
Appendix B, ATM Overview, provides a basic overview of ATM  
technology.  
1.2 DOCUMENT CONVENTIONS  
The following conventions are used throughout this document:  
Note symbol. Calls the reader’s attention to any item of  
information that may be of special importance.  
NOTE  
Tip symbol. Conveys helpful hints concerning procedures or  
TIP  
actions.  
Caution symbol. Contains information essential to avoid  
damage to the equipment.  
!
CAUTION  
Warning symbol. Warns against an action that could result in  
equipment damage, personal injury or death.  
Page 1-2  
BRIM-A6 User’s Guide  
 
BRIM-A6 Overview  
1.3 BRIM-A6 OVERVIEW  
The BRIM-A6 extends the functionality of your MIM or standalone hub  
to include remote bridging/routing capability. It allows remote  
connectivity using ATM technology.  
The BRIM-A6 is equipped with one slot that supports a Cabletron  
Systems APIM for ATM connectivity. Cabletron Systems provides a  
variety of APIMs that let you select the configuration of your choice.  
The BRIM-A6 supports two types of Virtual Channels: Permanent Virtual  
Channels (PVCs), and Switched Virtual Channels (SVCs). It also  
supports the ATM Forum’s User-Network-Interface (UNI) for SVC  
signaling, and FORE Systems’ Simple Protocol for ATM Network  
Signaling (SPANS). Because of this support, the BRIM-A6 is not only  
standards based, but takes advantage of FORE’s ATM signaling  
enhancements while providing guaranteed interoperability with existing  
FORE ATM networks.  
1.4 BRIM-A6 FEATURES  
ATM Port Interface Modules (APIMs)  
The BRIM-A6 uses Cabletron Systems APIMs for ATM connectivity.You  
can easily install APIMs into the BRIM for the interface of your choice.  
APIMs support multiple types of physical layer cable types and are fully  
compliant with the ATM Forum’s “UTOPIA” specification.  
MIB Support  
For additional information on how to extract and compile individual  
MIBs, refer to the Release Notes, or contact Cabletron Systems Technical  
Support (see Section 1.7, Getting Help).  
LANVIEW Diagnostic LEDs  
Cabletron Systems provides a visual diagnostic and monitoring system  
called LANVIEW with the BRIM-A6. LANVIEW LEDs help you  
quickly identify bridge and link status.  
BRIM-A6 User’s Guide  
Page 1-3  
 
Chapter 1: Introduction  
1.5 BRIM-A6 SPECIFICATIONS  
This section describes environment specifications and safety requirements  
for the BRIM-A6. Cabletron Systems reserves the right to change these  
specifications at any time without notice.  
Environment  
Operating Temperature:  
Storage Temperature:  
Operating Humidity:  
5°C to 40°C (41°F to 104°F)  
-30°C to 90°C (-22°F to 194°F)  
5% to 95% (non-condensing)  
Safety  
This unit meets the safety requirements of UL1950, CSA C22.2 No. 950,  
and EN60950.  
EMI  
This unit meets the EMI requirements of FCC Part 15 Class A, EN55022  
Class A and VCCI Class I.  
EMC  
This unit meets the EMC requirements of EN 50082-1 including: IEC  
801-2 (ESD), IEC 801-3 (Radiated Susceptibility), and IEC 801-4  
(EFT/B).  
1.6 RELATED MANUALS  
Use the following manuals to supplement the procedures and other  
technical data provided in this manual. This manual references procedures  
in these manuals, where appropriate, but does not repeat them.  
Cabletron Systems EMM-E6 Users Guide  
Cabletron Systems ESXMIM Installation Guide  
Cabletron Systems MicroMMAC Users Guide  
Cabletron Systems NBR-620/420/220 Installation Guide and  
NBR-620/420/220 Local Management Guide  
Page 1-4  
BRIM-A6 User’s Guide  
 
Getting Help  
1.7 GETTING HELP  
If you need additional support related to the BRIM-A6, or if you have any  
questions, comments, or suggestions concerning this manual, contact  
Cabletron Systems Technical Support:  
By phone  
(603) 332-9400  
Monday-Friday; 8 A.M. – 8 P.M. Eastern Time  
GO CTRON from any ! prompt  
ctron.com (134.141.197.25)  
anonymous  
By CompuServe  
By Internet mail  
By FTP  
Login  
Password  
your email address  
BRIM-A6 User’s Guide  
Page 1-5  
 
 
CHAPTER 2  
INSTALLATION  
This chapter contains instructions for unpacking the BRIM, installing  
APIMs, and installing the BRIM into Cabletron Systems devices that  
support BRIM technology.  
To install the BRIM and APIMs, you need the following tools:  
1 disposable grounding wrist strap (provided with any MIM or hub)  
1 Phillips-head screwdriver.  
The BRIM-A6 and the host MIM or hub are sensitive to static  
discharges. Use a grounding strap and observe all static  
precautions during this procedure. Failure to do so could result  
in damage to the BRIM-A6 or the host MIM or hub.  
!
CAUTION  
2.1 UNPACKING THE BRIM  
Unpack the BRIM as follows:  
1. Remove the shipping box material covering the BRIM.  
2. Carefully remove the module from the shipping box. Leave the  
module in its non-conductive bag until you are ready to install.  
3. Attach the disposable grounding strap to your wrist (refer to the  
instructions on the disposable grounding strap package).  
4. After removing the module from its non-conductive bag, visually  
inspect the device. If you notice any signs of damage, contact  
Cabletron Systems Technical Support immediately.  
BRIM-A6 User’s Guide  
Page 2-1  
 
Chapter 2: Installation  
2.2 INSTALLING APIMS  
To install an APIM into the BRIM-A6:  
1. Attach the disposable grounding strap to your wrist (refer to the  
instructions on the disposable grounding strap package).  
2. Remove the two faceplate screws from the BRIM. See Figure 2-1.  
3. Remove the three screws from the BRIM standoffs. See Figure 2-1.  
4. Insert the APIM connector into the BRIM connector. See Figure 2-1.  
APIM SCREWS  
APIM CONNECTOR  
STS  
LNK  
APIM  
STANDOFF  
BRIM  
CONNECTOR  
BRIM-A6  
STS  
PWR  
XMT  
RCV  
FACEPLATE SCREWS  
131101  
Figure 2-1 Installing an APIM  
5. Press down firmly on the APIM until the APIM connector slides all the  
way into the BRIM connector. Ensure the APIM sits flush on the  
standoffs.  
6. Secure the APIM with the screws provided with the APIM.  
7. Reattach the faceplate to the BRIM.  
Page 2-2  
BRIM-A6 User’s Guide  
 
 
Installing BRIMs  
2.3 INSTALLING BRIMS  
Only qualified personnel should install the BRIM.  
!
CAUTION  
You can install a BRIM in any Cabletron Systems device that supports  
BRIM technology (e.g., EMM-E6, MicroMMAC). Refer to the release  
notes for the version of firmware running on the Cabletron Systems  
device to ensure that the BRIM-A6 is supported.  
The following subsections provide generic instructions for installing a  
BRIM-A6 in a MIM or in a standalone hub. Refer to your specific MIM  
or standalone hub documentation for exact BRIM slot and connector  
locations.  
2.3.1 Installing a BRIM in a MIM  
To install a BRIM-A6 in a MIM that supports BRIM technology:  
1. Power-down the MMAC hub and remove all power cords.  
Cabletron Systems recommends that you power-down the hub  
even though Cabletron MIMs have “hot swap” capabilities.  
NOTE  
2. Disconnect all cables from the MIM. Note the ports to which these  
cables attach.  
3. Attach the disposable grounding strap to your wrist (refer to the  
5. Slide out the MIM, and place it on its side with the internal  
components facing up.  
6. Remove the mounting screws and the BRIM coverplate. See  
Figure 2-2.  
7. Remove the standoff screws. See Figure 2-2.  
BRIM-A6 User’s Guide  
Page 2-3  
 
Chapter 2: Installation  
STANDOFF SCREW  
STANDOFF  
BRIM  
COVERPLATE  
FACEPLATE  
MOUNTING SCREW  
142902  
Figure 2-2 Removing the BRIM Coverplate  
STANDOFF  
SCREW  
STS  
LNK  
APIM  
PWR  
STS  
BRIM-A6  
RCV  
XMT  
STANDOFF  
BRIM  
CONNECTOR  
FACEPLATE  
MOUNTING SCREW  
131102  
Figure 2-3 Installing the BRIM  
Page 2-4  
BRIM-A6 User’s Guide  
 
   
Installing BRIMs  
8. Place the BRIM behind the MIM faceplate. See Figure 2-3.  
9. Insert the connector pins of the BRIM-A6 into the BRIM connector on  
the MIM.  
10. Press down firmly on the back of the BRIM until the pins slide all the  
way into the connector holes.  
Ensure that the standoffs on the MIM align with the standoff  
screw holes on the BRIM.  
NOTE  
11. Reinstall the mounting screws and the standoff screws.  
12. Reinstall the MIM in the MMAC.  
13. Reattach all MMAC power cords.  
14. Reattach the network cabling to the MIM.  
15. Refer to Chapter 3 for instructions on configuring the BRIM-A6 using  
Local Management.  
2.3.2 Installing a BRIM in a Hub  
To install a BRIM-A6 into a standalone hub that supports BRIM  
technology:  
1. Power down the hub and remove the power cord.  
2. Disconnect all cables from the hub. Note the ports to which these  
cables attach.  
Ensure that you remove the power cord and ONLY the screws  
required to remove the chassis cover. Failure to comply could  
result in an electric shock hazard.  
3. Attach the disposable grounding strap to your wrist (refer to the  
instructions outlined on the disposable grounding strap package).  
4. Remove the hub chassis cover (refer to your specific hub  
documentation for instructions on removing the hub chassis cover).  
BRIM-A6 User’s Guide  
Page 2-5  
 
Chapter 2: Installation  
5. Remove the faceplate mounting screws and the BRIM coverplate.  
See Figure 2-2.  
6. Remove the standoff screws. See Figure 2-2.  
7. Place the BRIM behind the hub faceplate. See Figure 2-3.  
8. Insert the connector pins of the BRIM-A6 into the BRIM connector on  
the hub.  
9. Press down firmly on the back of the BRIM-A6 until the pins slide all  
the way into the connector holes.  
Ensure that the standoffs on the hub align with the standoff  
screw holes on the BRIM.  
NOTE  
10. Reinstall the faceplate mounting screws and the standoff screws.  
Ensure that the chassis cover is in place before reconnecting  
the power cord.  
11. Reattach the chassis cover to the hub, reconnect the power cord, and  
reconnect the hub to your network.  
12. Refer to Chapter 3 for instructions on configuring the BRIM-A6 using  
Local Management.  
Page 2-6  
BRIM-A6 User’s Guide  
 
CHAPTER 3  
LOCAL MANAGEMENT  
This chapter explains how to configure Permanent Virtual Connections  
(PVCs) using one of the following local management applications:  
Cabletron Systems Local Interface Management (LIM)  
Cabletron Systems Local Management (LM)  
The method used to configure PVCs depends on the firmware  
NOTES  
image of the host MIM or standalone hub. Refer to the section  
that applies to the local management application on your host  
MIM or standalone hub.  
To set up and access a local management application, refer to  
the host MIM or standalone hub user’s guide for instructions.  
Complete the following instructions before configuring the BRIM-A6  
using a local management application.  
An APIM must be installed in the BRIM-A6.  
The BRIM-A6 must be installed in the host MIM or standalone hub.  
The device must be up and running.  
A management terminal must be configured and properly connected to  
the host MIM or standalone hub in which the BRIM-A6 resides.  
Refer to Appendix B, ATM Overview for additional information  
concerning PVCs and ATM technology.  
NOTE  
BRIM-A6 User’s Guide  
Page 3-1  
 
Chapter 3: Local Management  
3.1 LOCAL MANAGEMENT KEYBOARD CONVENTIONS  
All key names appear in this manual as capital letters. For example, the  
Enter key appears as ENTER and the Backspace Key appears as  
BACKSPACE. Table 3-1 explains the keyboard conventions used in this  
manual as well as the key functions.  
Table 3-1 Keyboard Conventions  
Key  
Function  
ENTER Key and RETURN Key  
These are selection keys that perform  
the same LIM or LM function. For  
example, “Press ENTER” means that  
you can press either ENTER or  
RETURN, unless this manual  
specifically instructs you otherwise.  
SPACE bar and BACKSPACE Key  
These keys cycle through selections  
in some LIM and LM fields. Use the  
SPACE bar to cycle forward through  
selections and use BACKSPACE to  
cycle backward through selections.  
Arrow Keys  
These are navigation keys. Use the  
UP-ARROW, DOWN-ARRROW,  
LEFT-ARROW, and RIGHT-ARROW  
keys to move the screen cursor. For  
example, “Use the arrow keys”  
means to press whichever arrow key  
moves the cursor to the desired field  
on the screen.  
Page 3-2  
BRIM-A6 User’s Guide  
 
 
Using LIM to create PVCs  
3.2 USING LIM TO CREATE PVCs  
LIM consists of the ATM Connection Tables screen. This screen displays  
both Permanent Virtual Connections (PVCs) and Switched Virtual  
Connections (SVCs). SVCs are dynamic connections that are created and  
deleted as required by applications, equipment, and ATM facilities. SVCs  
can not be deleted from the ATM Connection Tables screen.  
To access the ATM Connection Tables screen, perform the following  
steps:  
1. Use the arrow keys to select BRIM 1 Extended Features from the  
Feature Selection screen.  
2. Press ENTER. The ATM Connection Tables screen, Figure 3-1  
appears.  
ATM Connection Tables  
Total Channels: 4  
Edit Static Entry:  
VPI:  
VCI:  
Mode: ADD  
Connection Table  
Index  
VPI  
0
VCI  
14  
15  
4
Type  
MAC ADDRESS  
1
2
3
4
0
2
3
10  
SAVE  
CLEAR VCCS  
NEXT  
PREVIOUS  
RETURN  
131104  
Figure 3-1 The ATM Connection Tables Screen  
BRIM-A6 User’s Guide  
Page 3-3  
 
 
Chapter 3: Local Management  
3.2.1 ATM Connection Tables Screen Fields  
The following list explains each of the ATM Connection Tables screen  
fields.  
Total Channels  
This field displays the number of active PVCs and SVCs connected to the  
BRIM-A6.  
Edit Static Entry  
The Edit Static Entry section consists of the Virtual Path Identifier (VPI),  
Virtual Channel Identifier (VCI), and Mode fields. These fields let you  
add or delete VPIs and VCIs from the Connection Table. The following  
list describes each of the Edit Static Entry Fields:  
VPI: This field lets you add (or delete) VPIs to the Connection Table.  
You can assign numbers 0-3 for VPIs.  
VCI: This field lets you add (or delete) VCIs to the Connection Table.  
You can assign numbers 0-1023 for VCIs.  
Mode: This field lets you select the edit mode. Select ADD to create  
PVCs on the Connection Table or DELETE to remove PVCs from the  
Connection Table.  
Connection Table  
The Connection Table displays the status of each PVC and SVC. The  
following list describes each of the Connection Table fields:  
Index: Displays the channel number of each PVC and SVC.  
VPI: Displays the VPI number of each PVC and SVC.  
VCI: Displays the VCI number of each PVC and SVC.  
Type: This field will be supported when the ATM Forum LAN  
Emulation is available.  
MAC ADDRESS: This field will be supported when the ATM Forum  
LAN Emulation is available.  
Page 3-4  
BRIM-A6 User’s Guide  
 
Using LIM to create PVCs  
3.2.2 ATM Connection Tables Screen Commands  
The following commands appear at the bottom of the ATM Connection  
Tables screen commands:  
Save  
This command lets you save all changes to the Connection Tables screen.  
Clear VCCs  
The Clear Virtual Channel Connection (VCC) command lets you clear all  
PVCs from the Connection Tables screen. This command does not let you  
clear SVCs from the Connection Tables screen because SVCs are  
dynamic connections that are created and deleted as required by  
applications, equipment, and ATM facilities.  
Connection 1 (VPI-0, VCI-14) and Connection 2 (VPI-0,  
VCI-15) are used by Fore Systems SPAN signalling and can  
NOTE  
not be deleted from the Connection Tables screen.  
Next/Previous  
This command lets you scroll to the next screen or back to the previous  
screen. If the ATM Connection Tables screen has over 6 channels, it  
automatically continues onto a new screen.  
Return  
This command lets you exit from the ATM Connections Tables screen.  
3.2.3 Using ATM Connection Tables Screen Commands  
To use ATM Connection Tables screen commands, perform the following  
steps:  
1. Use the arrow keys to highlight an ATM Connection Table screen  
command.  
2. Press ENTER, LIM executes the selected command.  
BRIM-A6 User’s Guide  
Page 3-5  
 
Chapter 3: Local Management  
3.2.4 Adding PVCs to the Connection Tables Screen  
To add PVCs to the Connection Tables screen, perform the following  
steps:  
1. Use the arrow keys to highlight the Mode field.  
2. Press ENTER to select ADD.  
3. Use the arrow keys to highlight the VPI field.  
4. Enter the VPI number you want to add and press ENTER.  
5. Use the arrow keys to highlight the VCI field.  
6. Enter the VCI number you want to add and press ENTER.  
7. Use the arrow keys to highlight the SAVE command at the bottom of  
the screen.  
8. Press ENTER. The “ADDING CHANNELS” message appears  
indicating that LIM has saved all changes to memory.  
3.2.5 Deleting PVCs from the Connection Tables Screen  
To delete PVCs from the Connection Tables screen, perform the  
following steps:  
1. Use the arrow keys to highlight the Mode field.  
2. Press ENTER to select DELETE.  
3. Use the arrow keys to highlight the PVC you want to delete.  
4. Use the arrow keys to highlight the SAVE command at the bottom of  
the screen.  
5. Press ENTER. The “DELETING CHANNELS” message appears  
indicating that LIM has saved all changes to memory.  
Page 3-6  
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Using LM to Create PVCs  
3.3 USING LM TO CREATE PVCS  
LM for the BRIM-A6 provides screens that let you add, delete or modify  
PVCs. This screen displays both Permanent Virtual Connections (PVCs)  
and Switched Virtual Connections (SVCs). SVCs are dynamic  
connections that are created and deleted as required by applications,  
equipment, and ATM facilities. SVCs can not be deleted from the LM  
screens. LM consists of the following screens:  
The BRIM-A6 Setup screen: This is a view only screen which displays  
the settings for each PVC and SVC.  
The BRIM-A6 Add/Delete Entry screen: This screen allows you to  
add, delete, and configure PVCs.  
To access BRIM-A6 LM, perform the following steps:  
1. Use the arrow keys to select the BRIM-A6 option from the Setup  
Menu screen.  
2. Press ENTER. The BRIM-A6 Setup screen, Figure 3-2, appears.  
Local Management  
Flash Image Version: XX.XX.XX  
BRIM-A6 SETUP  
ATM Port Total Current Connections: 2  
VPI  
0
VCI  
Encapsulation Type  
VC Mux Bridged 802.3  
LLC Encapsulation  
AAL Type  
Oper. Status  
Enabled  
0014  
0040  
5
0
3/4  
Disabled  
ADD/DELETE  
ENTRY  
PREVIOUS  
NEXT  
RETURN  
131105  
Figure 3-2 The BRIM-A6 Setup Screen  
BRIM-A6 User’s Guide  
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Chapter 3: Local Management  
3.3.1 BRIM-A6 Setup Screen Fields  
The BRIM-A6 Setup screen displays settings for each PVC and SVC that  
is configured to the BRIM. The following list explains each of the  
BRIM-A6 Setup screen fields:  
ATM Port Total Current Connections: X  
This field displays how many connections (PVCs and SVCs) are  
configured to the BRIM-A6.  
VPI  
This field displays the Virtual Path Identifier (VPI) of each connection.  
You assign VPIs in the BRIM-A6 Add/Delete Entry screen.  
VCI  
This field displays the Virtual Channel Identifier (VCI) of each  
connection. You assign VCIs in the BRIM-A6 Add/Delete Entry screen.  
Encapsulation Type  
This field displays the method used to encapsulate data at the ATM  
Adaptation Layer 5 (AA-L5) for each connection. The BRIM-A6  
supports the following methods of encapsulation:  
VC Mux 802.3 LANE:VC Based Multiplexed 802.3 LAN Emulation  
This method is specified by the ATM Forum LAN Emulation  
specification. This is the default encapsulation method.  
VC Mux Bridged 802.3: VC Based Multiplexing for bridged  
protocols as defined by the IETF RFC 1483.  
LLC Encapsulation: Logical Link Control for Bridged Protocols as  
defined by the IETF RFC 1483.  
AAL Type  
This field displays the ATM Adaptation Layer (AAL) type of each  
connection. The AAL divides the user information into segments suitable  
for packaging into series of ATM cells. The ATM Forum’s LAN  
Emulation specification dictates that AAL-5 be used for all LAN  
emulation traffic. The BRIM-A6 supports AAL-5 and AAL-3/4.  
Oper. Status  
This field displays the operational status of each connection. Possible  
conditions are Enabled or Disabled.  
Page 3-8  
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Using LM to Create PVCs  
3.3.2 BRIM-A6 Setup Screen Commands  
Commands appear at the bottom of the BRIM-A6 Setup screen. The  
following list explains each of the BRIM-A6 Setup screen commands:  
Previous  
This command lets you scroll to the previous screen (if the BRIM-A6  
Setup screen has over five connections, it automatically continues onto a  
new screen).  
Next  
This command lets you scroll to the next screen (if the BRIM-A6 Setup  
screen has over five connections, it automatically continues onto a new  
screen).  
Add/Delete Entry  
This command lets you access the BRIM-A6 Add/Delete Entry screen.  
Return  
This command lets you exit the BRIM-A6 Setup screen.  
BRIM-A6 User’s Guide  
Page 3-9  
 
Chapter 3: Local Management  
3.3.3 Using BRIM-A6 Setup Screen Commands  
To select BRIM-A6 Setup screen commands, perform the following steps:  
1. Use the arrow keys to highlight a BRIM-A6 Setup screen command.  
2. Press ENTER, LM executes the selected command.  
3.3.4 Accessing the BRIM-A6 Add/Delete Entry Screen  
To access the BRIM-A6 Add/Delete Entry screen from the BRIM-A6  
Setup screen, perform the following steps:  
1. Use the arrow keys to highlight the Add/Delete Entry selection at the  
bottom of the BRIM-A6 Setup screen.  
2. Press ENTER, the BRIM-A6 Add/Delete Entry screen Figure 3-3  
appears.  
Local Management  
Flash Image Version: XX.XX.XX  
BRIM-A6 ADD/DELETE ENTRY  
VPI  
VCI  
AAL Type  
Encapsulation Type  
0
0004  
[5]  
[VC Mux Bridged 802.3 ]  
ADD/MODIFY  
(DELETE)  
RETURN  
131106  
Figure 3-3 The BRIM-A6 Add/Delete Entry Screen  
Page 3-10  
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Using LM to Create PVCs  
3.3.5 BRIM-A6 Add/Delete Entry Screen Fields  
The BRIM-A6 Add/Delete Entry screen lets you add, delete, or modify  
PVCs. This screen does not let you clear SVCs from the Connection Table  
screen.  
Connection 1 (VPI-0, VCI-14) and Connection 2 (VPI-0,  
VCI-15) are used by Fore Systems SPAN signalling and can  
NOTE  
not be deleted from the Connection Table screen.  
The following list explains each of the BRIM-A6 Add/Delete Entry  
screen fields:  
VPI  
Use this field to enter the VPI of the PVC you want to add, delete or  
modify. This field allows values of 0-3.  
VCI  
Use this field to enter the VCI of the PVC you want to add, delete, or  
modify. This field allows values of 0-1023.  
AAL Type  
Use this field to select the ATM Adaptation Layer for the PVC you want  
to add, delete, or modify. Press the SPACE bar to toggle selections 5  
(AAL-5) and 3/4 (AAL-3/4). The default selection is 5.  
Encapsulation Type  
Use this field to select the data encapsulation type used over AAL-5. Press  
the SPACE bar to select VC Mux Bridged 802.3 or LLC Encapsulation.  
The default selection is VC Mux Bridged 802.3.  
BRIM-A6 User’s Guide  
Page 3-11  
 
Chapter 3: Local Management  
3.3.6 BRIM-A6 Add/Delete Entry Screen Commands  
The following commands appear at the bottom of the BRIM-A6  
Add/Delete Entry screen:  
Add/Modify  
This command lets you add or modify PVCs to the BRIM-A6 Add/Delete  
Entry screen.  
Delete  
This command lets you delete PVCs from the BRIM-A6 Add/Delete  
Entry screen. This command appears only after you add or modify an  
existing PVC.  
Return  
This command lets you exit from the BRIM-A6 Add/Delete Entry screen.  
3.3.7 Adding a PVC  
To add a PVC, perform the following steps:  
1. Use the arrow keys to highlight the VPI field and enter a VPI value  
from 0-3.  
LM automatically saves entries when you exit the field.  
NOTE  
2. Use the arrow keys to highlight the VCI field and enter a VCI value  
from 0-1023.  
3. Use the arrow keys to highlight the AAL Type field and press the  
SPACE bar until the desired AAL Type appears.  
4. Use the arrow keys to highlight the Encapsulation Type field and press  
the SPACE bar until the desired Encapsulation Type appears.  
5. Use the arrow keys to highlight the ADD/MODIFY command.  
6. Press ENTER. The “ENTRY ADDED” message appears at the top of  
the screen indicating that LM has added the PVC.  
Page 3-12  
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Using LM to Create PVCs  
3.3.8 Modifying a PVC  
To modify an existing PVC, perform the following steps:  
1. Use the arrow keys to highlight the VPI field and enter the VPI value  
you want to change.  
LM automatically saves entries when you exit the field.  
NOTE  
2. Use the arrow keys to highlight the VCI field and enter the VCI value  
you want to change.  
3. Use the arrow keys to highlight the AAL Type field and press the  
SPACE bar until the desired AAL Type appears.  
4. Use the arrow keys to highlight the Encapsulation Type field and press  
the SPACE bar until the desired Encapsulation Type appears.  
5. Use the arrow keys to select the ADD/MODIFY command.  
6. Press ENTER. The “ENTRY DELETED” then “ENTRY ADDED”  
messages appears at the top of the screen indicating that LM has  
modified the PVC.  
BRIM-A6 User’s Guide  
Page 3-13  
 
Chapter 3: Local Management  
3.3.9 Deleting a PVC  
To delete a PVC, perform the following steps:  
1. Use the arrow keys to highlight the VPI field and enter the VPI of the  
PVC you want to delete.  
LM automatically saves entries when you exit the field.  
NOTE  
2. Use the arrow keys to highlight the VCI field and enter the VCI of the  
PVC you want to delete.  
3. Use the arrow keys to highlight the AAL Type field and press the  
SPACE bar until the AAL Type of the PVC you want to delete  
appears.  
4. Use the arrow keys to highlight the Encapsulation Type field and press  
the SPACE bar until the Encapsulation Type of the PVC you want to  
delete appears.  
5. Use the arrow keys to highlight the DELETE command.  
6. Press ENTER. The “ENTRY DELETED” message appears at the top  
of the screen indicating that LM has deleted the PVC.  
Page 3-14  
BRIM-A6 User’s Guide  
 
CHAPTER 4  
LANVIEW LEDs  
This chapter describes how to use LANVIEW LEDs to monitor BRIM  
status and diagnose BRIM problems. Figure 4-1 shows the location of  
each of the BRIM-A6 LEDs as well as the APIM LEDs.  
BRIM-A6  
STS  
STS PWR  
LNK  
APIM  
XMT RCV  
131103  
Figure 4-1 The BRIM-A6  
4.1 BRIM-A6 LEDs  
Table 4-1 describes each of the BRIM-A6 LEDs.  
Table 4-1 BRIM LEDs  
LED  
Definition  
STS  
(Status)  
Green - Board OK.  
Red - Board Error.  
Yellow - Standby.  
PWR  
(Power)  
Green (on) - Power is on.  
Off - No power.  
XMT  
Green - Cells being transmitted.  
(Transmit)  
RCV  
Yellow - Cells being received.  
(Receive)  
BRIM-A6 User’s Guide  
Page 4-1  
 
   
Chapter 4: LANVIEW LEDs  
4.2 APIM LEDs  
Table 4-2 describes each of the APIM LEDs.  
Table 4-2 APIM LEDs  
LED  
Definition  
LNK  
(Link)  
Green - Have link.  
Off - No link.  
STS  
Green - APIM OK.  
(Status)  
Red - Fault with media. In most  
cases, the APIM automatically  
corrects this condition without  
interrupting operations. If the LED is  
red and remains red, contact  
Cabletron Systems Technical  
Support.  
Page 4-2  
BRIM-A6 User’s Guide  
 
 
APPENDIX A  
APIM SPECIFICATIONS  
This Appendix describes the ATM Port Interface Modules.  
A.1 APIM-11 SPECIFICATIONS  
Physical Interface:  
TAXI  
Media Type:  
Multimode Fiber  
100 Mbps  
SC  
Data Rate:  
Connector Type:  
Typical Link Distance:  
2 Kilometers  
A.2 APIM-21 SPECIFICATIONS  
Physical Interface:  
OC3  
Media Type:  
Multimode Fiber  
155 Mbps  
SC  
Data Rate:  
Connector Type:  
Typical Link Distance:  
2 Kilometers  
BRIM-A6 User’s Guide  
Page A-1  
 
Appendix A: APIM Specifications  
A.3 APIM-22 SPECIFICATIONS  
Physical Interface:  
STS3  
Media Type:  
Category V Unshielded Twisted  
Pair  
Data Rate:  
155 Mbps  
RJ45  
Connector Type:  
Typical Link Distance:  
100 Meters  
The APIM-22 is considered an ATM User Device and therefore has a  
different signal pin assignment that the ATM Network Equipment as  
specified by the ATM Forum User-Network Interface (UNI)  
specification. Figure A-1 shows the pin assignments for the APIM-22.  
STS  
LNK  
1 2 3 4 5 6 7 8  
APIM-22  
5. N/A  
1. Transmit +  
2. Transmit -  
3. N/A  
6. N/A  
7. Receive +  
8. Receive -  
4. N/A  
142912  
Figure A-1 APIM-22 Pin Assignments  
A.4 APIM-29 SPECIFICATIONS  
Physical Interface:  
OC3  
Media Type:  
Single Mode Fiber  
155 Mbps  
SC  
Data Rate:  
Connector Type:  
Typical Link Distance:  
25 Kilometers  
Page A-2  
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APIM-67 Specifications  
A.5 APIM-67 SPECIFICATIONS  
Physical Interface:  
DS3  
Media Type:  
75 Ohm Coaxial Cable  
Data Rate:  
45 Mbps  
BNC  
Connector Type:  
Typical Link Distance:  
136 Meters  
The APIM-67 does not use Cell Payload Scrambling.  
Scrambling must be disabled on any DS3 device connected to  
the APIM-67.  
!
CAUTION  
The APIM-67 conforms to the electrical characteristics specified by  
ANSI T1.404-1989 Carrier-to-Customer Installation-DS3 Metallic  
Interface Specification, section 5.12 Grounding Arrangements. In  
accordance with this specification, each channel (Transmit and  
jumper settings:  
Receive channel jumper - grounded  
Transmit channel jumper - not grounded  
Figure A-2 shows the location and default setting of each jumper. Refer  
to Figure A-2 if you need to change the jumper settings to properly  
connect the APIM-67 to another DS3 device.  
RECEIVE CHANNEL JUMPER (GROUNDED)  
TRANSMIT CHANNEL JUMPER (NOT GROUNDED)  
142910  
Figure A-2 The APIM-67 Default Jumper Settings  
BRIM-A6 User’s Guide  
Page A-3  
 
 
APPENDIX B  
ATM OVERVIEW  
This Appendix covers basic Asynchronous Transfer Mode (ATM)  
network operation and concepts that are critical to ATM network design  
and installation. The ATM Forum User-Network Interface Specification  
provides greater detail on ATM access methods and should be referenced  
whenever more information is needed. The scope of this appendix is to  
provide information regarding:  
Basic ATM Concepts.  
Basic ATM technology and how it works.  
B.1 ATM BASICS  
Asynchronous Transfer Mode (ATM) defines a method of transmitting  
and switching broadband information. This method highlights the use of  
relatively small, fixed-size cells (53 bytes) of information as opposed to  
large, variable-sized packets found in other networking transmission  
methods (ranging from 64 bytes to well over 4800 bytes). In addition, this  
method is being heralded as the first solution in erasing barriers between  
local-area networks and wide-area networks – providing voice, video, and  
data transmission.  
The use of small ATM cells provides cost, speed, manufacturing, and  
technical advantages over other existing transmission methods  
(i.e., Ethernet, Token Ring, and FDDI). This appendix touches upon  
several of these advantages and, when possible, describes them in as  
much detail as the scope allows.  
BRIM-A6 User’s Guide  
Page B-1  
 
Appendix B: ATM Overview  
B.2 THE ATM CELL  
One major difference between ATM and current transmission methods is  
that instead of using variable-length packets, ATM transmits fixed-size  
cells. (See Figure B-1.)  
Header  
5 Bytes  
Data  
48 Bytes  
Figure B-1 ATM Cells  
ATM uses three types of cells – Assigned, Unassigned, and Idle. Assigned  
cells carry actual traffic. Unassigned cells are free and waiting to be  
assigned traffic. Idle cells are used to separate cells, provide receiver  
synchronization (byte alignment), and reserve bandwidth for another  
channel (i.e., occupy bandwidth between transmissions). Idle cells do not  
receive traffic.  
ATM cells total 53 bytes long and consist of two general parts: the Header  
field and the Data field. The Header field consists of 5 bytes and contains  
management/control information for the cell. The Data field contains 48  
bytes of information. Figure B-2 shows the additional components of the  
Header field.  
Page B-2  
BRIM-A6 User’s Guide  
 
 
The ATM Cell  
Header  
Data  
Generic Flow Control (GFC)  
VPI  
Virtual Path Identifier (VPI)  
VCI/VPI  
Virtual Channel Identifier (VCI)  
VCI  
Payload Type  
Header Check Sequence  
Reserved  
Figure B-2 ATM Header Field Breakdown  
The Header field is made up of several sub-fields which provide  
management/control information relating to a cell. Brief descriptions of  
each header field are as follows:  
Generic Flow Control (GFC) – provides the ability to control the  
traffic flow for different grades of service.  
Virtual Path Identifier (VPI) – identifies the virtual path to which the  
cell belongs.  
Virtual Channel Identifier (VCI) – identifies the virtual channel to  
which the cell belongs.  
Payload Type Indicator (PTI) – describes whether the information is  
user information, network information, or management information.  
Header Check Sequence (HCS) – detects bit errors; corrects single bit  
errors.  
This method of fixed-cell length has many advantages over conventional  
packet transfer technologies; one major advantage is time. Since ATM  
cells are fixed in length, and all of the header data is the same, processing  
them is dramatically simplified. This eliminates the need for buffers and  
processors that tend to slow down transmission. By contrast, other LAN  
packets vary in length, making it necessary to check each incoming  
packet to ensure that it is complete and contains no errors.  
BRIM-A6 User’s Guide  
Page B-3  
 
 
Appendix B: ATM Overview  
B.3 THE ATM NETWORK  
ATM is a connection-oriented transmission technology. This means that  
no information transfers prior to establishing connection between devices.  
When preparing information, ATM uses Virtual Channels and Virtual  
Paths as cell addresses and places this channel data into the cell header.  
When transferring information, ATM combines these Virtual Channels  
and Virtual Paths into bundles, or “pipes” before sending them out over an  
ATM physical link segment.  
B.3.1 VIRTUAL CHANNELS AND VIRTUAL PATHS  
Rather than addressing cells to a specific destination, as in a LAN, ATM  
addresses cells to Virtual Channels (VCs) and/or Virtual Paths (VPs). This  
addressing takes place in the header field of the ATM cell.  
VCs and VPs are bi-directional (i.e., they transfer information in both  
directions on a single channel or path) and are “set-up” between devices  
on the ATM network prior to transmission. Similar to WAN transmission,  
ATM technology provides the ability of sending several VCs together  
over a VP, and several VPs over an ATM link segment (Figure B-3).  
VP 1  
VC 1  
VC 2  
VC 3  
VC 1  
VP 2  
ATM Link Segment  
Figure B-3 Virtual Channels and Virtual Paths  
Page B-4  
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ATM Protocol  
B.3.2 PERMANENT AND SWITCHED VIRTUAL  
CHANNELS  
ATM networks use two different types of Virtual Channels – Permanent  
Virtual Channels (PVCs) or Switched Virtual Channels (SVCs). The  
difference between PVCs and SVCs exists in the channel set-up.  
PVCs are pre-configured by an administration function, and are usually  
established for long term use. After setting-up this channel, nothing else is  
required by the network to transfer information between the two  
established points. This type of virtual channelling is established through  
a local or remote management interface.  
SVCs use a signaling and network switching procedure to set up  
dynamically. In other words, SVCs establish “on the fly,” as needed for a  
particular service, are used to transmit on the short term, and then  
terminated. Each time a specific channel is established, a routing protocol  
comes into play providing LAN-style operation and management.  
B.4 ATM PROTOCOL  
Existing PTM transmission technologies (Ethernet, Token Ring, FDDI)  
adhere to the International Organization for Standardization (ISO) Open  
System Interconnection (OSI) model. This seven layer model provides a  
consistent hierarchy of rules for developing system connection standards.  
In essence, OSI is a framework on which protocols for particular network  
types are based. It is important to note that the OSI model is different  
from the ATM model.  
A user’s perception of how a network operates is that it provides a direct  
link to another device. In reality, the information that the user sees is  
routed through the layers represented in the following models. Each layer  
modifies the information a user is either sending or receiving, according  
to the standards or protocol established for each individual layer.  
BRIM-A6 User’s Guide  
Page B-5  
 
Appendix B: ATM Overview  
When a message is sent out by a user:  
It passes from the highest layer in the model, the Applications Layer,  
down to the lowest layer, the Physical Layer.  
The Physical Layer physically transmits the message over a particular  
media.  
It passes upward, in the reverse order, from the Physical Layer to the  
Applications Layer.  
Each layer strips off the information that was added by its counterpart  
on the transmitting end. What you inevitably end up with is the same  
thing you started out with -- the original message. See the arrow flow  
in Figure B-4.  
Both the ATM model and the OSI model are comprised of seven layers.  
Fortunately, only the first three layers in each model differ. The following  
diagram illustrates the comparison between the ATM and the OSI models.  
7
6
5
4
3
2
1
7
6
5
4
3
2
1
Application  
Application  
Presentation  
Session  
Presentation  
Session  
Transport  
Transport  
Network  
ATM Adaptation  
ATM  
Data Link  
Physical  
Physical  
ATM Model  
OSI Model  
Figure B-4 ATM Model vs. OSI Model  
All of the upper layers (that is, Transport and higher) generally follow the  
same rules. The bottom three layers of the ATM model, however, replace  
the bottom three layers of the OSI model.  
Page B-6  
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ATM Protocol  
ATM provides the function of the first three layers of the OSI model, but  
performs all the information routing (cell switching) in only the Physical  
and Data Link Layer.  
Performing the information routing functions in the Physical and Data  
Link layers essentially bypasses the Network Layer. This allows ATM to  
process cells much quicker and more efficiently than packet-based  
routing.  
Since ATM differs with the OSI model in only its bottom three layers, a  
direct comparison of each layer provides the best method for  
understanding where these changes exist.  
Layer 1: Physical Layer  
In both models, the Physical Layer defines how information is transported  
over a network. This information includes all the physical connectors,  
pinouts, voltage levels, media type, and so on, that are considered valid  
for the network.  
The major difference between each model in the Physical Layer, is in the  
type of media considered suitable for transmission. While PTM  
transmission protocols specify certain media types, ATM is not limited to  
any particular media. Due to its fixed-cell construction, ATM is only  
limited to the media type it uses. For example, if ATM is operating over  
coaxial cable, it only performs at the level that coaxial cable allows.  
Layer 2:The Data Link Layer vs.The ATM Layer  
In the OSI model, the Data Link Layer is involved with data transmission,  
error detection, and flow control. The data link layer acts as a shield for  
higher network model layers by controlling transmission and reception.  
In the ATM model, the ATM layer defines the format of the ATM cell, and  
how it is transmitted over an ATM network. In addition, this layer defines  
the negotiated quality of service (QOS) and Traffic Management. This  
information is contained within the Header field of the cell.  
BRIM-A6 User’s Guide  
Page B-7  
 
Appendix B: ATM Overview  
Layer 3:The ATM Adaptation Layer vs.The Network Layer  
Even though these two layers have the same “physical” location in their  
perspective models, they are not alike. In the OSI model, the Network  
Layer formats data to be sent out on a particular network (for example, IP,  
or IPX). In the ATM model, since the Physical and ATM Layers take care  
of all the information routing normally performed by the Networking  
Layer, the ATM Adaptation Layer (AAL) acts as the first link between the  
ATM cell and the higher layer services.  
In this role, the AAL provides the convergence sub-layer (CS) and the  
segmentation and reassemble (SAR) sub-layer. When transmitting, the CS  
prepares data from the higher layers to be converted into cells. The SAR  
then segments the CS data into several 53 byte cells. Conversely, when  
receiving ATM cells, the SAR recombines data received from the ATM  
Layer and sends it to the higher layers.  
Page B-8  
BRIM-A6 User’s Guide  
 

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