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SG24-4817-00

IBM ATM Workgroup Solutions:

Implementing the 8285 ATM Switch

December 1996

This soft copy for use by IBM employees only.

IBML

International Technical Support Organization

SG24-4817-00

 

 

 

IBM ATM Workgroup Solutions:

Implementing the 8285 ATM Switch

December 1996

This soft copy for use by IBM employees only.

This soft copy for use by IBM employees only.

Take Note!

Before using this information and the product it supports, be sure to read the general information in Appendix F, ªSpecial Noticesº on page277.

First Edition (December 1996)

This edition applies to the ATM Workgroup Switch with microcode level 1.4.

Comments may be addressed to:

IBM Corporation, International Technical Support Organization

Dept. HZ8 Building 678

P.O. Box 12195

Research Triangle Park, NC 27709-2195

When you send information to IBM, you grant IBM a non-exclusive right to use or distribute the information in any way it believes appropriate without incurring any obligation to you.

Copyright International Business Machines Corporation 1996. All rights reserved.

Note to U.S. Government Users Ð Documentation related to restricted rights Ð Use, duplication or disclosure is subject to restrictions set forth in GSA ADP Schedule Contract with IBM Corp.

This soft copy for use by IBM employees only.

Contents

Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

vii

Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ix

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

xi

How This Redbook Is Organized . . . . . . . . . . . . . . . . . . . . . . . . . . .

xi

The Team That Wrote This Redbook . . . . . . . . . . . . . . . . . . . . . . . . .

xii

Comments Welcome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

xiii

Chapter 1. Introduction to ATM Networks . . . . . . . . . . . . . . . . . . . . . .

1

1.1ATM Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.1.1ATM Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.1.2ATM Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.1.3ATM Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.1.4ATM Data Flows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Chapter 2. Introduction to the IBM 8285 Nways ATM Workgroup Switch . . . 9

2.18285 Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.2Base Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.2.1Internal Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.2.28285 Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2.2.3155 Mbps ATM I/O Card . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2.3Expansion Unit (FC 5502) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2.3.1Internal Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2.3.2Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2.4Installable Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Chapter 3. Functional Overview of the IBM 8285 . . . . . . . . . . . . . . . . . 17

3.1IBM 8285 Architecture Overview . . . . . . . . . . . . . . . . . . . . . . . . . 17

3.2Switching Fabric . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

3.2.1Switching in the IBM 8285 . . . . . . . . . . . . . . . . . . . . . . . . . . 22

3.2.2Switching Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

3.3Control Point Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

3.3.1Control Point Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

3.3.2Control Point V1.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

3.3.3Control Point V1.3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

3.3.4Control Point V1.4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

3.4

ATM Backplane / Expansion Unit Connection . . . . . . . . . . . . . . . . .

33

3.5

LAN Emulation Server Functions . . . . . . . . . . . . . . . . . . . . . . . . .

33

Chapter 4. IBM 8285 ATM Modules . . . . . . . . . . . . . . . . . . . . . . . . .

35

4.1

Modules Currently Available for the 8285 ATM Subsystem . . . . . . . . .

35

4.2

Some Common Elements among the 8285 Modules . . . . . . . . . . . . .

36

4.2.1Maximum Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

4.2.2Variable VPC/VCC Value Ranges . . . . . . . . . . . . . . . . . . . . . . 36

4.3 ATM 12-Port 25 Mbps UTP Concentrator Module . . . . . . . . . . . . . . . 38

4.3.1Sample Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

4.4ATM 2-Port 155 Mbps Flexible Media Module and ATM 3-Port 155 Mbps

LAN Concentration Module . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . .

42

4.4.1

Differences between the 2- and 3-Port ATM Modules

. . . . . . . . . .

43

4.4.2

ATM 155 Mbps Media Module Traffic Management

. . . . . . . . . . .

43

Copyright IBM Corp. 1996

iii

This soft copy for use by IBM employees only.

4.4.3Sample Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

4.5ATM 4-Port 100 Mbps MIC Fiber Module and the ATM 4-Port 100 Mbps

SC Fiber Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

4.5.1Sample Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

4.6Video Distribution Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

4.6.1MPEG Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

4.6.2

Configuring the Video Distribution Module . . . . . . . . . . .

. . . . .

52

4.6.3

Sample Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . .

54

4.7 ATM 4-Port TR/Ethernet Bridge Module . . . . . . . . . . . . . . .

. . . . .

57

4.7.2

Sample Configurations Using ATM TR/Ethernet Bridge Module

. . .

58

4.7.3

ATM TR/Ethernet Bridge Module and LAN Emulation

. . . .

. . . . .

61

4.7.4

Association between IP and MAC Address . . . . . . . . . . .

. . . . .

62

4.7.5

ATM TR/Ethernet Bridge Module Configuration Utility Program

. . .

62

4.7.6

Running and Stored Configuration Parameters . . . . . . . .

. . . . .

66

4.8 ATM WAN Module . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . .

67

4.8.1

A02 WAN ATM Physical Interface Supported . . . . . . . . . .

. . . . .

67

4.8.2VPD Installation Considerations . . . . . . . . . . . . . . . . . . . . . . 68

4.8.3Sample Scenario . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

4.9LAN Switching Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

4.9.1Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

4.9.2Sample Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

Chapter 5. 8285 ATM Network Specifications

. . . . . . . . . . . . . . . . . . . 81

5.1ATM Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

5.1.1Supported VPI and VCI Range . . . . . . . . . . . . . . . . . . . . . . . 81

5.1.2

Supported Virtual Connection Types . . . . .

. . . . . . . . . . . . . . .

82

5.1.3

Maximum Number of Connections Supported

. . . . . . . . . . . . . .

82

5.1.4How PVCs Are Supported . . . . . . . . . . . . . . . . . . . . . . . . . . 83

5.1.5How to Configure PVCs . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

5.1.6How PVPs Are Supported . . . . . . . . . . . . . . . . . . . . . . . . . . 85

5.1.7How to Define PVPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

5.1.8

How a VPI/VCI Is Allocated to SVCs . . . . . . . . .

. . . . . . . . . . .

86

5.1.9

How Point-to-Multipoint Connections Are Supported

. . . . . . . . . .

87

5.1.10

8285 LAN Emulation Specifications . . . . . . . . .

. . . . . . . . . . .

88

5.2Traffic Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

5.2.1Service Classes Supported by the IBM 8285 ATM Workgroup . . . . . 90

Chapter 6. IBM 8285 Planning and Installing . . . . . . . . . . . . . . . . . . . . 91

6.1Physical Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

6.1.1Packaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

6.1.2Physical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

6.1.3ATM Ports and Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

6.1.4Planning for Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

6.2Logical Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

6.2.1Capacity Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

6.2.2Standards Compliances . . . . . . . . . . . . . . . . . . . . . . . . . . 103

6.3Install . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

6.3.1Physical Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

6.3.28285 Console . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

6.3.3 ATM Concentration Module Basic Configuration Process Steps . . 109 6.4 Microcode/Picocode Considerations . . . . . . . . . . . . . . . . . . . . . 110

6.4.1Reasons for Upgrading Microcode . . . . . . . . . . . . . . . . . . . . 110

6.4.2Acquiring the Latest Microcode . . . . . . . . . . . . . . . . . . . . . . 111

6.4.3Upgrading the Microcode . . . . . . . . . . . . . . . . . . . . . . . . . 115

ivATM Workgroup Solutions: Implementing the 8285 ATM Switch

This soft copy for use by IBM employees only.

Chapter 7. IBM 8285 Configuration . . . . . . . . . . . . . . . . . . . . . . . . . 123

7.1Configuring Classical IP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

7.1.1Classical IP Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . 123

7.1.2Configuring a Simple CIP Network . . . . . . . . . . . . . . . . . . . . 123

7.1.3Troubleshooting Your CIP Network . . . . . . . . . . . . . . . . . . . . 126

7.1.4

Configuring a Local Multi-Switch Network for CIP . . . . . . . . . . .

128

7.2

Configuring LAN Emulation . . . . . . . . . . . . . . . . . . . . . . . . . . .

131

7.2.1

8285 LAN Emulation Functions Overview . . . . . . . . . . . . . . . .

131

7.2.2

LAN Emulation Parameters . . . . . . . . . . . . . . . . . . . . . . . .

131

7.2.3

Configuring a Simple LANE Network . . . . . . . . . . . . . . . . . . .

135

7.2.4

Troubleshooting Your LANE Network . . . . . . . . . . . . . . . . . .

139

Chapter 8. IBM 8285 Management . . . . . . . . . . . . . . . . . . . . . . . . .

145

8.1

Management Information Bases (MIBs) . . . . . . . . . . . . . . . . . . .

145

8.2

IBM Nways Campus Manager ATM Overview . . . . . . . . . . . . . . . .

148

8.3

IBM Nways Campus Manager ATM for AIX . . . . . . . . . . . . . . . . .

149

8.3.1Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149

8.3.2Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154

8.3.3Using Nways Campus Manager ATM for AIX with IBM 8285 . . . . . 156

8.3.4 IBM 8285 Node Related Information . . . . . . . . . . . . . . . . . . . 159

8.4Nways Manager for Windows . . . . . . . . . . . . . . . . . . . . . . . . . . 167

8.4.1Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

8.4.2Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170

8.4.3

Using Nways Manager for Windows with IBM 8285 . . . . . . . . . .

170

Appendix A.

8285 ATM Control Point Commands . . . . . . . . . . . . . . . .

171

A.1

Command Line Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . .

171

A.1.1

How to Access the Command Line Interface . . . . . . . . . . . . . .

171

A.1.2

Access Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

173

A.1.3

How to Change Administrator and User Password . . . . . . . . . .

173

A.1.4

Resetting the Password to Factory Default . . . . . . . . . . . . . . .

174

A.1.5

How to Change Terminal Settings . . . . . . . . . . . . . . . . . . . .

174

A.2

IBM 8285 ATM Command List . . . . . . . . . . . . . . . . . . . . . . . . .

176

Appendix B. Pinouts for Ports and Cables . . . . . . . . . . . . . . . . . . . .

179

B.1

Pinouts for ATM25 and Other Common Network Connectors . . . . . .

179

B.2

Other Cabling Considerations . . . . . . . . . . . . . . . . . . . . . . . . .

179

B.2.1

Converter Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

180

B.2.2

Crossover Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

180

Appendix C. Part Numbers for Key Components . . . . . . . . . . . . . . . .

181

Appendix D. Hints and Tips for the ATM 4-Port TR/Ethernet Bridge Module

183

Appendix E.

IBM ATM Campus Switch Private MIBs . . . . . . . . . . . . .

195

Appendix F. Special Notices . . . . . . . . . . . . . . . . . . . . . . . . . . . .

277

Appendix G. Related Publications . . . . . . . . . . . . . . . . . . . . . . . . .

279

G.1

International Technical Support Organization Publications . . . . . . . .

279

G.2

Redbooks on CD-ROMs . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

279

G.3

Other Publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

279

How To Get ITSO Redbooks . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

281

How IBM Employees Can Get ITSO Redbooks . . . . . . . . . . . . . . . . . .

281

Contents v

This soft copy for use by IBM employees only.

How Customers Can Get ITSO Redbooks . . . . . . . . . . . . . . . . . . . . .

282

IBM Redbook Order Form . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

283

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

285

List of Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

291

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

295

vi ATM Workgroup Solutions: Implementing the 8285 ATM Switch

This soft copy for use by IBM employees only.

Figures

1.ATM Addressing Format Cell . . . . . . . . . . . . . . . . . . . . . . . . . . 2

2.ATM UNI/NNI Format Data Cells . . . . . . . . . . . . . . . . . . . . . . . . 3

3.ATM Call Establishment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

4.ATM Classical IP using ARP Server . . . . . . . . . . . . . . . . . . . . . . 6

5. Front Panel of the IBM 8285 Nways ATM Workgroup Switch Base Unit . 11

6.Front Panel of the IBM 8285 Nways ATM Workgroup Switch Expansion

 

Unit . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . .

14

7.

Inserting a Module in the Expansion Unit

. . . . . . . . . . . . . . . . . . .

15

8.

Attaching the Expansion Interface Cable

. . . . . . . . . . . . . . . . . . .

16

9.Hardware Architecture of the IBM 8285 Nways ATM Workgroup Switch

Base Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

10.Hardware Architecture of the IBM 8285 Nways ATM Workgroup Switch

 

Base and Expansion Unit . . . . . . . . . . . . . . . . . . . . . . . . .

. . .

21

11.

Internal Cell Format of the IBM 8285 Nways ATM Workgroup Switch

. .

24

12.

ATM 12-Port 25 Mbps UTP Concentrator Module Workgroup . . . .

. . .

39

13.

8285 Low-Cost Configuration Implementation . . . . . . . . . . . . .

. . .

40

14.8285 with ATM 12-Port 25 Mbps UTP Concentrator Modules as an

Access Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

15.ATM 2-Port 155 Mbps Flexible Media Module High-Performance

Workgroup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

16.ATM 3-Port 155 Mbps LAN Concentration Module with Redundant

Backbone Links . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . .

45

17. ATM 100 Mbps MIC/SC Fiber Module Workgroup Configuration

. . . . .

46

18.ATM 100 Mbps MIC/SC Fiber Module with Redundant ATM Backbone

 

Links

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . .

47

19.

Typical MEPG-2 Picture Sequence Showing Picture Types

. . . . . . . .

51

20.

Video Distribution Module Workgroup Configuration . . .

. . . . . . . . .

54

21.

Video Distribution Module for Campus Video Distribution

. . . . . . . . .

55

22.Video Distribution Module with ATM WAN for Enterprise Video

Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

23.Local LAN to ATM Server Bridging . . . . . . . . . . . . . . . . . . . . . . 59

24.

Local LAN Bridging and ATM Server Access . . . . .

. . . . . . . . . . .

60

25.

Campus LAN Interconnect and ATM Server Access .

. . . . . . . . . . .

61

26.

ATM TR/Ethernet Bridge Module Configuration Window

. . . . . . . . . .

63

27.The ATM TR/Ethernet Bridge Module Service Port Connection . . . . . . 64

28.Windows Displayed by the ATM TR/Ethernet Bridge Module

 

Configurator . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . .

65

29.

A Typical ATM WAN Module Configuration . . . . . . . . . . .

. . . . . . .

70

30.

Relieving Token-Ring Congestion with LAN Switching Module

. . . . . .

77

31.

Relieving Ethernet Congestion with LAN Switching Module .

. . . . . . .

79

32.Sample PVC Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

33.Sample PVP Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

34.LAN Information Frame Location . . . . . . . . . . . . . . . . . . . . . . . . 89

35.

Complex ATM Network Using ATM 8285 . . . .

. . . . . . . . . . . . . .

103

36.

Logon Screen of the IBM

8285 Console . . . . .

. . . . . . . . . . . . . .

107

37.

Sample Screen to Check

the Physical Installation

. . . . . . . . . . . .

108

38.Simple CIP Network - Physical View . . . . . . . . . . . . . . . . . . . . . 124

39.Simple CIP Network - Logical View . . . . . . . . . . . . . . . . . . . . . 124

40.Multi-Switch CIP Network - Physical View

41.Multi-Switch CIP Network - Logical View

42.A Simple LANE Network - Physical View

. . . . . . . . . . . . . . . . .

128

. . . . . . . . . . . . . . . . . .

129

. . . . . . . . . . . . . . . . . .

136

Copyright IBM Corp. 1996

vii

This soft copy for use by IBM employees only.

43. A Simple LANE Network - Logical View . . . . . . . . . . . . . .

44.The Console Screen of a Simple LANE Network Configuration

45.The Sample Console Screen to Check the Physical Connection

46.The Sample Console Screen to Check the LANE Registration

47.The Sample Console Screen to Check the LANE Registration

. . . . .

136

. . . . .

138

. . . .

140

. . . . .

141

. . . . .

142

48.NetView for AIX Root Submap . . . . . . . . . . . . . . . . . . . . . . . . 157

49.ATM Campus Submap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158

50.ATM Campus Submap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159

51.IBM 8285 ATM Node View - Star . . . . . . . . . . . . . . . . . . . . . . . 160

52.IBM 8285 Node Profile Panel . . . . . . . . . . . . . . . . . . . . . . . . . 161

53.IBM 8285 Node Configuration Panel . . . . . . . . . . . . . . . . . . . . . 162

54.IBM 8285 Device View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163

55.IBM 8285 Node Call Logging Panel . . . . . . . . . . . . . . . . . . . . . 166

56. IBM 8285 Node LAN Emulation Panel . . . . . . . . . . . . . . . . . . . . 166

57.ELAN View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

58.Changing Administrator Password . . . . . . . . . . . . . . . . . . . . . . 173

59.Changing User Password . . . . . . . . . . . . . . . . . . . . . . . . . . . 174

60.Changing the Terminal Baud Rate . . . . . . . . . . . . . . . . . . . . . . 174

61.Changing the Terminal Data Bits . . . . . . . . . . . . . . . . . . . . . . . 174

62.Changing the Terminal Parity . . . . . . . . . . . . . . . . . . . . . . . . . 175

63.Changing the Terminal Stop Bits . . . . . . . . . . . . . . . . . . . . . . . 175

64.Changing the Terminal Prompt . . . . . . . . . . . . . . . . . . . . . . . . 175

65. Disabling the Terminal Auto Hangup . . . . . . . . . . . . . . . . . . . . 175

66.Changing the Terminal Timeout . . . . . . . . . . . . . . . . . . . . . . . 176

67.Saving the Terminal Settings . . . . . . . . . . . . . . . . . . . . . . . . . 176

68.Showing the Terminal Settings . . . . . . . . . . . . . . . . . . . . . . . . 176

69. Output from Show Terminal Command . . . . . . . . . . . . . . . . . . . 176

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Tables

1.Control Point Levels Summary of the IBM 8285 Nways ATM Workgroup

Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

2.ATM Buses Implemented in the IBM 8285 Nways ATM Workgroup

 

Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . .

33

3.

ATM 155 Mbps Media Module Supported I/O Cards . . . . . . . . .

. . .

42

4.

Video Distribution Module Comparison of MPEG-2 and Motion-JPEG

. .

52

5.

VC Values by Port for VDM Module (VP=0) . . . . . . . . . . . . . .

. . .

53

6.ATM Physical Interface Support . . . . . . . . . . . . . . . . . . . . . . . . 67

7.

A02 WAN I/O Card VPD Part Numbers . . . . . . . . . . . . .

. . . . . . .

69

8.

A Comparison of 8285

Token-Ring LAN Switch Modules . . .

. . . . . . .

75

9.

A Comparison of 8285

Ethernet LAN Switch Modules . . . .

. . . . . . .

75

10.

Bandwidth Improvement with Token-Ring LAN Switch Module

. . . . . .

78

11.Bandwidth Improvement with Ethernet LAN Switch Module . . . . . . . . 79

12. Supported Connection Type by the A-CPSW Module . . . . . . . . . . . . 82

13.LANE Information Field Lengths . . . . . . . . . . . . . . . . . . . . . . . . 89

14.Types of Traffic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

15. Traffic Management Functions Support . . . . . . . . . . . . . . . . . . . . 90

16.Environmental Specifications of the IBM 8285 Nways ATM Workgroup

Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

17.Mechanical Specifications of the IBM 8285 Nways ATM Workgroup

 

Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . .

93

18.

Power Supply Specifications of the 8285 . . . . . . . . . . . . . .

. . . . .

93

19.

Power Supply Specifications of Future 8285 Models . . . . . . .

. . . . .

93

20.

Power Budget of the 8285 Expansion Chassis . . . . . . . . . . .

. . . . .

94

21.

Connection Capacity of IBM 8285 Nways ATM Workgroup Switch

. . . .

98

22.Transmit Delay (Latency per Port) . . . . . . . . . . . . . . . . . . . . . . . 98

23.

Bandwidth Capacity of the IBM 8285 Nways ATM Workgroup Switch

. .

99

24.

LES/BUS Capacity of the IBM 8285 Nways ATM Workgroup Switch

. .

100

25.TRS Capacity of the IBM 8285 Nways ATM Workgroup Switch and IBM

 

8260 Nways Multiprotocol Switching Hub . . . . . . . . . . . . . . . . . .

101

26.

References and Process Quick Guide . . . . . . . . . . . . . . . . . . . .

109

27.

Filenames for System Upgrade Microcode (Release 1.0-1.2) . . . . . .

114

28.

Filenames for System Upgrade Microcode (Release 1.3-1.4) . . . . . .

114

29.

Filenames for Module Upgrade Microcode (Release 1.4) . . . . . . . .

114

30.

Download Errors and Suggested Fixes . . . . . . . . . . . . . . . . . . .

119

31.Swap Errors and Suggested Fixes . . . . . . . . . . . . . . . . . . . . . . 120

32.Necessary Parameters for 8285 #1 . . . . . . . . . . . . . . . . . . . . . 124

33.Necessary Parameters for 8285 #2 . . . . . . . . . . . . . . . . . . . . . 129

34.IX Status Messages and Causes . . . . . . . . . . . . . . . . . . . . . . . 130

35.Address Assignment Rule for the IBM 8285 Nways ATM Workgroup

Switch LAN Emulation Components . . . . . . . . . . . . . . . . . . . . . 132

36.Necessary Parameters for 8285#1 . . . . . . . . . . . . . . . . . . . . . . 137

37.

8285 Configurations SET Commands Quick Reference List . . . . . . .

172

38.

IBM 8285 Nways ATM Workgroup Switch ATM Command List . . . . .

177

39.

RJ-45 Pin Assignments by Network Type . . . . . . . . . . . . . . . . . .

179

40.

Pin Assignments for Converter Cable (P/N 10H3904) . . . . . . . . . . .

180

41.

Pin Assignments for Switch-to-Switch Crossover Cable . . . . . . . . .

180

42.Spare Parts and Accessories . . . . . . . . . . . . . . . . . . . . . . . . . 181

Copyright IBM Corp. 1996

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x ATM Workgroup Solutions: Implementing the 8285 ATM Switch

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Preface

This redbook provides a detailed overview of the IBM 8285 Nways ATM Workgroup Switch, from both functional and operational viewpoints. It provides everything you need to know to plan, implement, debug, manage, and maintain an ATM network using the 8285 switch. It includes scripted and tested configuration scenarios to simplify and expedite the initial implementation, and debugging and tuning guidelines to optimize the ATM network. In addition, it covers the very latest modules and features of the 8285/8260 family of ATM switches, including the ATM WAN Module, and the Video Distribution Module.

This book is intended for all networking personnel involved in planning, implementing, and/or maintaining an ATM network based on the IBM 8285 Nways ATM Workgroup Switch. A working knowledge of ATM is helpful but not necessary.

How This Redbook Is Organized

This redbook contains 296 pages. It is organized as follows:

Chapter 1, ªIntroduction to ATM Networksº

This chapter provides an overview of ATM, LAN Emulation, and Classical IP networks. This information provides a basis for understanding many of the operational aspects of the IBM 8285 Nways ATM Workgroup Switch.

Chapter 2, ªIntroduction to the IBM 8285 Nways ATM Workgroup Switchº

This chapter provides an overview of the major features of the IBM 8285 Base Unit and the IBM 8285 Expansion Chassis. This information will familiarize the reader with the overall layout and design of the 8285 switch

Chapter 3, ªFunctional Overview of the IBM 8285º

This chapter provides a detailed view of the functions of the 8285 switch and how it performs them. Included are details about the internal architecture, switching mechanisms (including an in-depth technical description of the switching process), control point codes, and the capabilities of the integrated Forum-Compliant LAN Emulation server.

Chapter 4, ªIBM 8285 ATM Modulesº

This chapter provides an overview of the many modules that can be installed with the 8285 switch. These modules provide performance and flexibility, and enable the 8285 switch to be used in a wide variety of network configurations.

Chapter 5, ª8285 ATM Network Specificationsº

This chapter provides an overview of the ATM capabilities specific to the 8285 switch. The overview includes discussions of which ATM features are supported, what the maximum system capabilities are, and how these capabilities might be implemented.

Chapter 6, ªIBM 8285 Planning and Installingº

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This chapter provides an overview of the 8285 installation process. This includes physical and logical planning information, as well as details about the 8285 microcode and how to upgrade it.

Chapter 7, ªIBM 8285 Configurationº

This chapter provides information on how to configure and troubleshoot a network of 8285 switches. Both Classical IP ATM networks and LAN Emulation ATM networks are discussed. Actual console samples are included, where appropriate, to facilitate understanding.

Chapter 8, ªIBM 8285 Managementº

This chapter provides a discussion of how to manage an 8285 network using either an ASCII console or an SNMP-based network management platform. Various operational aspects are discussed as well.

Appendix A, ª8285 ATM Control Point Commandsº

This appendix provides an overview of the 8285 console, its functions, and its supported commands.

Appendix B, ªPinouts for Ports and Cablesº

This appendix provides pin-out diagrams for the ATM25 RJ-45 ports.

Appendix C, ªPart Numbers for Key Componentsº

This appendix contains a list of components and part numbers.

Appendix D, ªHints and Tips for the ATM 4-Port TR/Ethernet Bridge Moduleº

This appendix contains information concerning the latest release of code for the ATM 4-Port TR/Ethernet Bridge Module.

Appendix E, ªIBM ATM Campus Switch Private MIBsº

This appendix contains the latest version of the IBM campus ATM switch private MIB.

The Team That Wrote This Redbook

This redbook was produced by a team of specialists from around the world working for the Systems Management and Networking ITSO Center, Raleigh.

This project was designed and managed by Georges Tardy, LAN Campus Specialist at the Systems Management and Networking ITSO Center, Raleigh, working in La Gaude, France. He joined IBM in 1965, and was previously a hardware development engineer of campus hub products at La Gaude Laboratory, France.

The authors of this document are:

Marc Fleuette is a Senior Networking Technical Specialist from the IBM North American Sales and Services organization. He has been with IBM for nine years, in both marketing and technical positions, including two years as Technical Internetworking Marketing Specialist. He currently provides pre-sales technical support for IBM′s family of campus internetworking products, including hubs, routers, and switches, for both ATM and traditional LANs. He has a B.S. in Industrial Engineering and a B.A. in History/English, both from Lehigh University in Bethlehem, PA, USA.

xii ATM Workgroup Solutions: Implementing the 8285 ATM Switch

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Tadashi Murayama is an Advisory Networking I/T Specialist in IBM Japan. He has been with IBM Japan for 11 years in the Field Support Organization and has been in charge of the networking products, such as the CCU/NCP and the LAN products. He holds a degree in LL.B. from Gakusyuin University in Tokyo, Japan. His areas of expertise include traditional SNA networking, legacy LAN protocols (token-ring, Ethernet, FDDI), and campus ATM protocols and related products.

Thanks to the following people for their invaluable contributions to this project:

Aroldo Yuji Yai

Systems Management and Networking ITSO Center, Raleigh.

Ange Aznar

IBM La Gaude

Our grateful acknowledgement for their contribution to this work by the following IBM La Gaude Product Engineering people:

Benoit Panier

Michel Leblais

Pierre-Olivier Martin

Olivier Caillau

Bernard Putois

Jacques Baroghel

Eric Montagnon

Comments Welcome

We want our redbooks to be as helpful as possible. Should you have any comments about this or other redbooks, please send us a note at the following address:

redbook@vnet.ibm.com

Your comments are important to us!

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Chapter 1. Introduction to ATM Networks

This book is designed to help you to get the most effective use of the IBM 8285 Nways ATM Workgroup Switch as you implement an ATM network. Before going into further details about the 8285, however, it might be useful to review the basics of ATM networking, addressing, and data flows.

1.1 ATM Fundamentals

Asynchronous Transfer Mode (ATM) is a high-performance network technology that is rapidly becoming the standard for high-speed LAN and WAN networks, both public and private. It combines the flexibility and resiliency of

connection-less protocols, such as TCP/IP, with the efficiency and manageability of session-oriented protocols, such as SNA. This is because ATM uses small, fixed-size packets called cells which are transported across the network

hop-by-hop along a pre-determined virtual path that can be quickly changed to avoid congestion or failures. Both of these concepts are discussed below.

1.1.1 ATM Cells

ATM uses the concept of cells as its basic delivery vehicle. These cells are similar to the packets (or frames) used in traditional networks, except for two distinguishing features:

1.Fixed Cell Size

All ATM cells are 53-bytes long, of which 48 bytes are payload, and 5 bytes are header information. This payload-size provides the best combination of efficiency (favoring large payloads for data) and latency (favoring small payloads for time-sensitive applications such as voice and video).

The header contains all the information necessary for the cell to enter the network, to be carried to its next (intermediate) destination, and to identify simple errors (single-bit) that might occur.

The most important thing about the fixed cell size, however, is that it enables cells to be switched simply and efficiently, in hardware, without costly (in time and money) large buffers.

2.Minimal Routing Information

ATM cells are connection-oriented, which means that they are not responsible for identifying a destination or determining the best route. In fact, the only routing information necessary is the current hop information (which the next switch uses in its forwarding decision). And, since all cells for a given session follow the same path, no provision is necessary for

out-of-sequence arrival. Thus, unlike traditional LAN packets, sequencing numbers are not required, and addressing at the MAC and network layers is eliminated (for native ATM applications). The result is more data, less overhead, and simpler hardware-based switching

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1.1.2 ATM Connections

ATM, being session-oriented, requires that a path through the network be determined and maintained for the duration of the session. This path is comprised of virtual channel links (switch-to-switch connections), which are linked together to form a virtual channel connection (VCC) (end-to-end connection), which are aggregated into virtual paths (VP). Just like a virtual channel (VC), a virtual path can be a virtual path link (switch-to-switch connection) or a virtual path connection (VPC) (end-to-end connection). More importantly, a virtual path can be switched to a new route (to avoid congestion or a failure) without affecting or individually processing the VCs it contains.

Connections through the network can be either fixed and pre-determined, or can be defined dynamically through a signalling protocol. A pre-determined path, defined by the network operator, is called a permanent virtual connection (PVC), while a dynamically determined temporary path is called a switched virtual connection (SVC). In either case, a connection will be implemented only if there is adequate capacity in the network to meet the requisite end-to-end bandwidth and Quality of Service (QoS) parameters, or if an existing connection can be preempted to make it possible to meet bandwidth and QoS requirements.

1.1.3 ATM Addressing

Figure 1. ATM Addressing Format Cell

An ATM address consists of two parts: a 13-byte network prefix and a 7-byte terminal identifier (consisting of a 6-byte end station identifier (ESI), and a 1-byte selector field). Further information on specific requirements for ATM addressing can be found in IBM 8285 Nways ATM Workgroup Switch: Installation and Users Guide and in ISO-8348 (CCITT X.213). Of specific relevance to us, are the following addressing restrictions:

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1.The network prefix must be unique and consistent within a given ATM network. It is defined at each switch in the network and consists of an

11-byte network address and a 2-byte area identifier, which is further divided in to a 1-byte ATM Cluster Number(ACN), and a 1-byte Hub Number (HN). This results in a hierarchical network topology of:

a.An ATM network comprised of

b.ATM sub-networks (or clusters) comprised of c. ATM hubs

In any given ATM network, all switches will have an ATM address with the same first 11 bytes. In any given ATM cluster, all switches will have an address with the same first 12 bytes, and every switch will have a unique 13-byte network prefix.

This hierarchical organization allows for very efficient topology calculation and distribution, since updates can be localized to a given cluster, or, where appropriate, to devices connected to an adjacent cluster or network.

2.The network prefix must begin with either 39 (corresponding to IEEE 802

(LAN) Format), 45 (corresponding to ITU-T (E.164) Format), or 47 (corresponding to OSI Format). Generally speaking, it doesn′t matter which

format you choose, however, specific bytes have specific significance in each format, and, consequently, care should be taken in choosing a format, especially if your ATM network will be connected to other ATM networks.

1.1.4ATM Data Flows

Figure 2. ATM UNI/NNI Format Data Cells

Chapter 1. Introduction to ATM Networks 3

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Because ATM allows for dynamic registration of resources, signalling processes have been established to provide for initial registration, connection setup, and connection teardown, whether the connection is native ATM, ATM

Forum-Compliant LAN Emulation, or Classical IP (CIP).

1.1.4.1 Basic ATM Signalling

Figure 3. ATM Call Establishment

For an endstation to communicate in a switched environment such as ATM, it must register with the network, request a connection when necessary, and clear the connection when through. For native ATM endstations, this is done by the following:

Initial Registration: When an endstation wishes to enter the network, it must first register its full ATM address with its associated switch. This signalling process is described in ATM UNI Specification 3.0 (based on ITU-T Q.93B recommendations), or more recently, in ATM UNI Specification 3.1 (based on ITU-T Q.2931 recommendations) and is performed when the endstation is activated. During this process, the workstation receives its 13-byte network prefix from the switch, appends its own local address (ESI plus selector), and registers its complete ATM address with the switch.

Connection Setup: When an endstation wishes to communicate with another endstation, it must first establish a connection to it. It does this by issuing a SETUP request to the ATM network.

If the requested address is local, the switch acknowledges the request by issuing a CALL PROCEEDING response to the requesting endstation and forwarding the SETUP request to the requested endstation, which acknowledges receipt with a CALL PROCEEDING response.

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If the requested endstation is not local, the switch will forward the request to the correct switch based on routing information compiled and maintained by the 8285 ATM Control Point′s Topology and Routing Services (TRS) subsystem. The path will be selected based on the widest path (not the shortest) available between the end-points. This path information is appended to the setup request and is used by intermediate switches to determine the next hop through the network. There can be no more than 15 hops in any given path.

If the requested workstation is able to accept the incoming connection, it issues a CONNECT response to the network, which forwards it back to the requesting workstation, where it is acknowledged by issuing a CONNECT ACK response to the network which forwards it to the destination endstation to complete the call set-up process.

Connection Tear-Down: When an endstation wishes to end a connection, it issues a DISCONNECT request to the network. The network acknowledges the request by returning a RELEASE response (instructing the requesting endstation to drop all resources associated with the call), and by forwarding the DISCONNECT on to the destination workstation, which acknowledges the request by returning a RELEASE command to the network. The process is completed when the requesting endstation returns a RELEASE COMPLETE to the network, which forwards it to the destination endstation, indicating that the call has been dropped and the associated resources freed up.

1.1.4.2 ATM Forum-Compliant LAN Emulation (LANE)

LAN emulation simplifies a migration from a traditional LAN environment to an ATM switched environment by superimposing LAN interfaces on top of the underlying ATM transport and by supporting traditional LAN addressing (at the media access control (MAC) layer) as well as broadcast and multicast capabilities. This means that LAN-based applications run unchanged, yet now have access to to the network and to network-attached resources at scalable speeds from 25 Mbps to 155 Mbps and beyond.

The signalling process used by LANE is analogous to that for basic ATM signalling, except that instead of a control point providing directory services, there is now a LAN Emulation Server (LES) which provides directory services at the MAC layer (which provides MAC address to ATM address mapping) for LAN Emulation Clients (LECs). The 8285 ATM Control Point has two LES entities, which together can handle 128 clients, distributed between two Ethernet or token-ring ELANs. Either of the 8285 ATM Control Point′s two LECs can use these internal LESs or can be configured to use an external LES, such as the IBM Multiprotocol Switched Services Server, providing for greater flexibility, for larger ELANs, and for inter-ELAN routing and bridging.

Emulating a traditional LAN environment requires the ability to allow for broadcast traffic (common in a connectionless environment), while handling it in a fashion optimized for a connection-oriented environment. This function is addressed by the Broadcast/Unknown address Server (BUS), which attempts, with the LES, to convert MAC broadcast traffic to a specific ATM destination address. The 8285 ATM Control Point integrates this BUS function with the internal LES function. Either of the 8285 ATM Control Point′s two LE clients can also be configured to use an external BUS, such as the IBM Multiprotocol Switched Services Server, providing for very sophisticated broadcast management, especially in IP and IPX environments.

Chapter 1. Introduction to ATM Networks 5

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To avoid having to configure the LES′s address at each endstation, LANE provides for a Lan Emulation Configuration Server (LECS), which LECs can query for their proper LES address. This enables backup LESs to be configured, since should the primary LES fail, the LECS merely has to direct connections to a backup LES without having to change any configuration in the workstation. Although the 8285 ATM Control Point does not contain an LECS, either or both of the internal LECs can be configured to use an external LECS, such as that provided by the IBM Multiprotocol Switched Services Server.

This section was intended only as an overview of LANE. For a more detailed description of these functions, please see IBM 8260 As a Campus ATM Switch, SG24-5003 and ATM Campus Introduction, Planning, and Troubleshooting Overview, GA27-4089.

1.1.4.3 Classical IP (CIP)

Figure 4. ATM Classical IP using ARP Server

Classical IP (RFC 1577) is a protocol-specific VLAN (PVLAN) technology that has been widely adopted in the Internet working community. It provides for layer 3 routing of IP datagrams over an ATM network. In many ways, it is analogous to LANE. For instance, all endstations must register with an address resolution server (called a LES in LANE, but an Address Resolution Protocol (ARP) Server in CIP). Once the endstation is registered with the address resolution server, it is, by definition, part of a virtual broadcast domain (an ELAN in LANE terminology, but a VLAN in CIP, known as a Logical IP Subnet (LIS)). The 8285 ATM Control Point has a single CIP client entity.

Here are the CIP data flows:

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CIP Address Registration: Because in CIP there is no function analogous to the LECS in LANE, each endstation must be configured with the ATM address of its ARP server. The ARP client establishes a connection to the ARP server, and notifies it of its IP address and its ATM address. The ARP server adds these to its ARP table, so that it can respond properly to other ARP requests.

CIP Address Resolution: When a CIP client wishes to establish IP communication with another IP device, it issues an ARP to the ARP server to determine the ATM address of the other device. If the ARP server has an entry that matches the IP address of the requested device, it returns the ATM address of that device to the requesting endstation, which caches it in its own ARP table. If however, the ARP server doesn′t have the IP address in its ARP table, it returns an ARP_FAILURE to the requesting client. The client now forwards the unresolvable address to its default gateway for further handling. If the gateway can resolve the address, it returns its IP and ATM addresses to the client to be cached. If the gateway cannot resolve the address, it returns an ARP_FAILURE to the client and the address resolution process terminates.

CIP Data Forwarding: When a device wishes to forward data to another CIP device, it must first check to see if it knows the other device′s ATM address (that is, its ARP table contains an entry for the desired destination device). If so, it merely establishes a direct connection with the other device, and forwards data to it. If not, it must first resolve the address (see ªCIP Address Resolutionº above), then setup a connection, and then forward data directly.

A more complete discussion of Classical IP can be found in IBM 8260 As a Campus ATM Switch, SG24-5003 and ATM Campus Introduction, Planning, and Troubleshooting Overview, GA27-4089.

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Chapter 2. Introduction to the IBM 8285 Nways ATM Workgroup Switch

The IBM 8285 Nways ATM Workgroup Switch (hereafter called the 8285 switch) is an ATM switch for the workgroup environment that provides a low-cost ATM solution as either a stand-alone switch or as an access node to the rest of the enterprise. Using your existing wiring it provides up to 25 Mbps of bandwidth to users. The 8285 switch can connect users to any ATM network at speeds up to 155 Mbps, and even has forum-compliant LAN emulation built-in to make implementation easier.

In addition, the IBM 8285 Nways ATM Workgroup Switch is expandable, using the optional 8285 expansion chassis which enables it to take advantage of most of the many ATM modules available for the IBM 8260 Nways Multiprotocol Switching Hub. This provides you with ability to:

Create even larger workgroups

Service more high-speed devices (such as servers)

Provide more bandwidth in to your ATM backbone network

Connect existing token-ring or Ethernet users directly to the ATM backbone

Connect to remote sites using public ATM services at speeds from 34 Mbps up to 155 Mbps

Distribute video information across your ATM network and make it accessible using standard TV monitors

The following sections provide an overview of the 8285 switch.

2.1 8285 Components

The 8285 switch is comprised of the following components:

Standard:

Base Unit:

-12 ATM 25.6 Mbps ports

-I/O slot for optional uplink (see below)

Optional:

155 Mbps ATM I/O Card which can be installed in the IBM 8285 Base Unit:

-Multi-mode Fiber (MMF)

-Single-mode Fiber (SMF)

Expansion Unit

Installable 8285/8260 ATM Modules

Copyright IBM Corp. 1996

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Note

Although there are two models of the 8285 switch, the 8285-00B and the 8285-00P, they are identical except that the latter includes 12 workstation adapters, providing a total solution at a special bundled price.

2.2 Base Unit

The base unit is comprised of the following:

Internal Features:

An ATM cell switching function

A switch control function, called the 8285 ATM Control Point

Front Panel Features:

Ports:

-12 ATM ports that support ATM 25.6 Mbps operation over standard copper wiring

-A slot for an optional high-speed uplink to provide 155 Mbps access to either a server or to an ATM backbone

LEDs:

-System Status

-Port Status

Connectors:

-A connector to connect the optional expansion unit

-A connector to connect a standard ASCII console

2.2.1Internal Features

The IBM 8285 Base Unit contains a planar which controls the 8285 switch and its external interfaces.

2.2.1.1 ATM Cell Switching in the IBM 8285 Base Unit

The ATM switching mechanism installed in the base only switches ATM cells between ports in the base unit. This is accomplished by basically taking what would normally be the backplane output and connecting it directly to what would normally be the backplane input.

When an IBM 8285 Expansion Chassis is connected to the IBM 8285 Base Unit, however, this connection is disabled, and the traffic from the IBM 8285 Base Unit uses the switch-on-a-chip that is incorporated in the IBM 8285 Expansion Chassis.

2.2.1.2 8285 ATM Control Point

The 8285 ATM Control Point is integrated in the base unit and provides the following functions:

Manages the functions of the IBM 8285 Base Unit as well as the optional 8285 Expansion Chassis and its inserted modules.

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Controls the ATM cell switching between appropriate ports and performs the functions associated with the establishment and management of ATM circuits.

Provides a management interface (via an SNMP manager or an ASCII/TELNET terminal) for monitoring, configuration, and microcode distribution.

Provides an Forum-Compliant LAN Emulation implementation which supports:

Integrated LAN Emulation Server (LES)/Broadcast and Unknown Server (BUS)

There are two instances of the LES/BUS in the 8285 ATM Control Point, allowing up to two Emulated LANs (ELANs), either token-ring or Ethernet, to be configure.

Integrated LAN Emulation Client (LEC)

There are two instances of the LEC configurable in the 8285 ATM Control Point, allowing the 8285 ATM Control Point to be accessible from up to two ELANs, either token-ring or Ethernet.

LAN Emulation Configuration Server (LECS)

Although the LECS function is not integrated in to the 8285 ATM Control Point, support is provided for using an external LECS by using its

well-known address, or by getting its ATM address through the ILMI protocol.

2.2.28285 Front Panel

Figure 5 shows the front panel of the IBM 8285 base unit.

Figure 5. Front Panel of the IBM 8285 Nways ATM Workgroup Switch Base Unit

As found in the Figure 5, there are ports, LEDs, connectors and a button that the user can access from the front panel.

Chapter 2. Introduction to the IBM 8285 Nways ATM Workgroup Switch 11

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2.2.2.1 Ports

The IBM 8285 Base Unit has the following ATM ports:

12 ATM25 Ports

Fully compliant with the ATM Forum Physical Interface Specification for 25.6 Mbps over Twisted Pair Cable

Use standard RJ-45 connectors

Support standard twisted pair cabling, either shielded or unshielded

1 ATM155 Port (Optional):

This port is further described in 2.2.3, ª155 Mbps ATM I/O Cardº on page 13.

2.2.2.2 LEDs

The front panel has LEDs for two purposes:

1.Port LEDs:

Port Enable

Output Activity

2.Switch Status LEDs:

Power

OK

Fault

2.2.2.3 Connectors

The front panel has four connectors:

Power Input

The power input connector matches the country-specific power cord that is shipped with the base unit. The power supply itself is an auto-sensing universal power supply.

Console Port

The console port is a standard RS-232 25-pin D-shell male interface for connecting either an ASCII console or a modem in order to perform the initial configuration.

Expansion Connector

The expansion connector is a 68-pin female connector used to attach the IBM 8285 Expansion Chassis using an expansion interface cable shipped with the IBM 8285 Expansion Chassis shipping group.

Advanced Diagnostics Connector

The advanced diagnostics connector is a 9-pin connector used only by authorized service personnel for advanced diagnostics. This connector is not needed in any case to install and configure the 8285 switch.

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2.2.2.4 Reset Button

The reset button resets both the IBM 8285 Base Unit and the optional IBM 8285 Expansion Chassis with its inserted modules.

For more information about the LEDs, the connectors, and the reset button, refer to the IBM 8285 Nways ATM Workgroup Switch: Installation and Users Guide, SA33-0381.

2.2.3 155 Mbps ATM I/O Card

The 155 Mbps ATM I/O Card is an optional card installable in the 155 Mbps Feature I/O Card Slot of the base unit. There are two types of 155 Mbps ATM I/O Cards available, Multimode Fiber (FC 5500) and Single-Mode Fiber (FC 5501). It becomes the 13th port of base unit and can be linked to an ATM station or to another ATM switch that supports ATM 155, such as another 8285 switch or an 8260 hub.

2.2.3.1 Connectors

Both I/O cards have SC connectors.

2.2.3.2 LEDs

The 155 Mbps ATM I/O Card has the following LEDs:

Status

Output Activity

Error

2.3 Expansion Unit (FC 5502)

The 8285 Expansion Chassis provides three slots to receive IBM 8260/8285 ATM modules, extending the 8285 switch′s functions and capacities.

The IBM 8285 Expansion Chassis consists of the following:

Internal Features:

An ATM backplane that is similar to the one used in the 8260 hub.

A planar containing a switch-on-a-chip, which connects the base unit ATM ports to each other and to other ATM modules in the IBM 8285 Expansion Chassis.

External Features:

Slots

Connectors

LEDs

A rack-mountable chassis with an integrated, auto-sensing universal power supply

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2.3.1 Internal Features

The IBM 8285 Expansion Chassis has two primary internal features.

2.3.1.1 ATM Backplane

The IBM 8285 Expansion Chassis contains an ATM backplane that is effectively a three-slot version of the 8260 hub′s ATM backplane. That is to say, it is a completely passive backplane with female connectors. It is capable of supporting most 8260 hub ATM modules.

Note

However, there are some differences between the ATM backplanes of the IBM 8285 and IBM 8260. Specifically, the IBM 8260 ATM Control Point and Switch Module cannot be used in the IBM 8285 Expansion Chassis. For more information, refer to Chapter 3, ªFunctional Overview of the IBM 8285º on page 17.

2.3.1.2 ATM Planar

The IBM 8285 Expansion Chassis contains a planar which has a switch-on-a-chip switching module. When connected to the IBM 8285 Base Unit with the expansion interface cable, the switch-on-a-chip performs all the port-to-port cell switching:

Between ports in the IBM 8285 Base Unit

Between ports in the IBM 8285 Base Unit and ATM modules in the IBM 8285 Expansion Chassis

Between ports on ATM modules in the IBM 8285 Expansion Chassis

2.3.2 Front Panel

Figure 6 shows the front panel of the IBM 8285 expansion unit.

Figure 6. Front Panel of the IBM 8285 Nways ATM Workgroup Switch Expansion Unit

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As shown in the Figure 6, there are slots, LEDs, and connectors that the user can access from the front panel.

2.3.2.1 Slots

The expansion unit has three slots that can support most of the IBM 8260 ATM modules. The modules that are supported in the IBM 8285 Expansion Chassis are listed in Chapter 4.

Figure 7 shows how the modules are inserted in the IBM 8285 Expansion

Chassis.

Figure 7. Inserting a Module in the Expansion Unit

2.3.2.2 LEDs

The expansion unit has the following switch status LEDs:

Power

OK

Fault

2.3.2.3 Connectors

The expansion unit front panel has two connectors:

Power Input

Base Connector

The base unit connector is a 68-pin female connector just like expansion unit connector of the base unit. It is connected to the IBM 8285 Base Unit by the expansion interface cable which is shipped with the expansion unit.

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Figure 8. Attaching the Expansion Interface Cable

For more information about the LEDs and the connectors, refer to the IBM 8285 Nways ATM Workgroup Switch: Installation and Users Guide, SA33-0381.

2.4 Installable Modules

All ATM modules designed for the IBM 8260 Nways Multiprotocol Switching Hub can be used in the IBM 8285 Expansion Chassis. Refer to 4.1, ªModules Currently Available for the 8285 ATM Subsystemº on page 35 for the list of modules that are officially supported with the 8285 switch.

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Chapter 3. Functional Overview of the IBM 8285

This chapter contains the following sections describing the functional overview of the IBM 8285:

IBM 8285 Architecture Overview

Switching Fabric

Control Point Codes

ATM Backplane / Expansion Unit Connection

LAN Emulation Server Functions

3.1IBM 8285 Architecture Overview

This section discusses the architecture of the IBM 8285.

Figure 9 on page 18 shows the hardware architecture of the IBM 8285 Base Unit.

Copyright IBM Corp. 1996

17

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Figure 9. Hardware Architecture of the IBM 8285 Nways ATM Workgroup Switch Base Unit

As shown above, the IBM 8285 Base Unit contains the following functional components:

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Management and Control Components:

Control Point components:

-Processing Components

Flash memory, to store the microcode

8M byte DRAM, for operational code and tables

Motorola M68040 processor, to execute the microcode

-Management Components:

M360 processor, to handle the console interface (the same as the IBM 8260)

Data Handling Components:

CAP/CAD components to process cells, both inbound and outbound

Specific Front End (SFE) components to handle the physical interfaces, inbound and outbound, for all ATM ports, including:

-ATM 25 Mbps ports

-ATM 155 Mbps port. While this SFE is physically located on the optional 155 Mbps ATM I/O Card, it can be treated as functionally part of the base unit.

-ATM control-point port.

3.1.1.1 8285 ATM Control Point

The 8285 ATM Control Point has a processor and flash memory. The flash memory holds the boot strap code and also the operational code. The control point performs the following functions:

Signalling entities

Resource management

Address mapping

Topology and route selection

Node management and inband or out-of-band console interface

Integrated LES/BUS

The control point manages the rest of the ATM subsystem by sending control cells via an internal port connected to the 25 Mbps HS.SFE.

3.1.1.2 CAP, CAD and SFE

The CAP, CAD and SFE are internal components implemented on the IBM 8285 Base Unit, as well as in each of the ATM modules. Their functions are as follows:

CAP/CAD Components:

CAP (Common ATM Processor)

The CAP handles the cell routing, queuing, scheduling, and traffic management. It determines what the routing header for the internal cell should be and gives the information to the CAD to build the cell.

CAD (Common ATM Datamover)

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The CAD function prepares the cell for transmission to the switch. The CAD builds the internal cell in its RAM according to instructions given by the CAP.

As described in 3.1, ªIBM 8285 Architecture Overviewº on page17, the IBM 8285 base unit is treated as a single module and all ports in the base unit share two sets of CAP/CAD, one set to handle the inbound cells, called CAP_up and CAD_up, and the other set to handle the outbound cells, called CAP_down and CAD_down.

SFE (Specific Front End)

The SFE handles the ATM front-end concentration and dispatch. Its main role is to deliver the cell from any ATM interface to the CAD.

There are three sets of SFE components in the base unit: an inbound/outbound pair for the ATM25 ports, called HS.SFE_up/HS.SFE_down, an inbound/outbound pair for the ATM155 port, called SFE_up/SFE_down, and a single, bidirectional SFE used by the control point, called the CP SFE.

In addition, each ATM module also uses CAP, CAD, and SFE components, but in two sets: an inbound set (CAP_Up, CAD_Up, and SFE_Up), and an outbound set (CAP_Down, CAD_Down, and SFE_Down). Note that this slightly different from the 8285 switch which has the additional CP SFE, and which connects CAD_up directly to CAD_down when operating without an expansion unit.

Figure 10 on page 21 shows the hardware architecture of the IBM 8285 Base Unit when connected to the IBM 8285 Expansion Chassis.

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Figure 10. Hardware Architecture of the IBM 8285 Nways ATM Workgroup Switch Base and Expansion Unit

When the IBM 8285 expansion unit is installed, its switch chip, called a switch-on-a-chip, becomes the primary cell switch for the 8285 system. The

CAD_up and CAD_down devices in the base unit and in any ATM modules link directly to this switch. Another way of saying this is that the link between the base unit′s CAD_up and CAD_down is disabled, and all cells (even port-to-port) within the base unit or within an individual ATM module, are switched through the switch-on-a-chip.

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Additional Information

The switch-on-a-chip is a scalable, non-blocking, shared buffer switching module that was developed at the IBM Research Laboratory in Zurich, Switzerland. This is the same switch that is used in other IBM ATM switches, such as the IBM 8260 Nways Multiprotocol Switching Hub and the IBM Nways 2220 Broadband Network Switch.

The architecture of the expansion unit is similar to that of the IBM 8260:

Each module contains CAP/CAD components to interface to the ATM backplane.

The ATM backplane is fully passive and uses female connectors to improve availability.

The ATM backplane is point-to-point wired to connect each module directly to the switch-on-a-chip.

Note

This means that the IBM 8260 ATM CPSW Module is not supported in the

IBM 8285 Expansion Chassis, which also means that any

CPSW-exclusives, such as switch redundancy, are not supported.

However, the architecture is different in several key ways:

The control point is in a separate module (the base unit) from the switch.

The control point shares a set of CAP/CAD components with the ATM ports.

3.2Switching Fabric

As described above, there are two switching mechanisms used in the IBM 8285, depending on whether the base unit is operating with or without an expansion unit. The following sections describe in detail the switching mechanism in each case.

3.2.1 Switching in the IBM 8285

This section describes the switching mechanism in the IBM 8285.

Before going into further details about the switching function of the 8285 switch, it is necessary to understand the internal frame format it uses. This format is described below.

3.2.1.1 Internal Cell Format

The 8285 switch uses the same internal frame format, a 64-byte extension of the standard 53-byte ATM cell, as the 8260 hub. This cell is constructed by the following process:

The ATM cell received from a port by the SFE.

The SFE calculates a header error check value and compares it to the HEC that arrived in the cell′s header.

If no error is detected (the calculated and transmitted HEC values match), the SFE strips the HEC from the cell′s header and sends the resulting 52-byte

ATM cell to the CAP/CAD.

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The CAP/CAD adds a 2-byte internal header (called a routing header (RH)), and 1-byte trailer.

The RH contains the information necessary to route the internal cell. Basically, the switching information is contained in the Source Blade (SB) and Target Blade (TB) fields, which correspond to ports on the

switch-on-a-chip, and which the switch uses in order forward the cell to the correct blade(s). The switch itself does not use destination port or VPC/VCC number when switching the cell. However, at the module level, the CAP/CAD would forward the cell to the appropriate port(s) based on the target port (TP) contained in the format field of the RH.

Note: In this context, blade refers to the set of components that share a common CAP/CAD. This is normally a module, such as an ATM media module or the ATM Control Point and Switch module of the IBM 8260. However, by this definition, the IBM 8285 Base Unit can be considered a blade or module as well, since its ports share a common CAP/CAD.

Figure 11 on page 24 shows the internal cell format used in the IBM 8285. Note the internal cell format will be changed in future releases but the concept should remain similar and able to be referenced.

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1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3

 

 

0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

 

 

 

TB

 

TBE

LCBAul SB

LCBAuh

 

RH (8 byte)

 

 

 

 

NBA

 

F1

 

F2

 

 

 

GFC

 

VPI

 

 

VCI

 

PT

CL ATM Header

(4 byte: without HEC)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ATM payload (48 byte)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Future Use

TB:

Target Blade

TBE:

Target Blade Extension

LCBAul:

Leaf Control Block Address up(inbound) lower port

LCBAuh:

Leaf Control Block Address up(inbound) higher port

NBA:

Next Buffer Address

F1:

Format Field 1st

F2:

Format Field 2nd

GFC:

Generic Flow Control

VPI:

Virtual Path Identifier

VCI:

Virtual Channel Identifier

PT:

Payload Type

CL:

Cell Loss Priority

HEC:

Header Error Control

Figure 11. Internal Cell Format of the IBM 8285 Nways ATM Workgroup Switch

3.2.1.2 Switching without the Switch Chip

When no expansion chassis is connected, the IBM 8285 Base Unit implements a direct connection between CAD_up and CAD_down. This means that inbound cells would undergo the following process:

1.The SFE_up strips the HEC from valid cells and forwards the cell to the CAD_up.

2.The CAD_up prepares the internal cell and forwards it directly to the CAD_down.

3.The CAD_down uses the RH information to determine which ports to forward the cell to, strips the internal header, and forwards the 52-byte cell to the SFE_down.

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4.The SFE_down performs the appropriate label-swapping, calculates a new HEC, and forwards the 53-byte cell across the physical interface.

Blade number 0 is assigned to the blade for the base unit.

Note

The blade number is used for the internal switching and is different from physical slot number.

3.2.1.3 Switching the Switch Chip

When the IBM 8285 Expansion Chassis, with its switch-on-a-chip, is connected, the connection between the base unit′s CAD_up and CAD_down is disabled, and all traffic flows through the switch-on-a-chip. This means that Step 2 above becomes the following:

2A. The CAD_up prepares the internal cell and forwards it across the expansion interface cable to the switch-on-a-chip.

2B. The switch-on-a-chip decides which blade(s) to forward the cell to and forwards it to the CAD_down of the target blade(s) for further handling.

3.2.2Switching Scenarios

The following describes the process of how cells are switched from one port to another port in the IBM 8285. To understand this process it is best to follow a cell as it enters one port and exits another and to see what actually happens as it goes through the various components. Please refer to 3.2.1.1, ªInternal Cell Formatº on page 22, as the following discussion assumes that you are already familiar with the internal cell format.

Point-to-Point Routing

The following describes what happens to a cell in a point-to-point connection:

1.Receive the cell.

a.CAD_Up prepares in advance, for every port, the address of the next cell assembly buffer. This is the location where the internal cell will be built in CAD_Store.

b.An ATM cell is received by SFE_Up. Here the HEC of the ATM header gets checked. If it is a bad cell, it is discarded, otherwise the HEC is stripped and the remaining 52 bytes are delivered to CAD_Up.

c.The connection from SFE_Up to CAD_Up is 32-bits wide so the cell is transferred in 13 4-byte blocks. There are port lines between SFE_Up and CAD_Up which indicate what port the cell came from. Using these port lines, the 4-byte block transfers can be mixed from different ports. For example, deliver a 4-byte block from Port 1, then deliver a 4-byte block from Port 2, then deliver a 4-byte block from Port 1 and so on. This ensures that no time is wasted in delivering data from a port that has no cells.

d.When the first 4-byte block of a cell gets transferred, one of the control lines is raised to indicate the beginning of a cell.

e.The SFE forwards each 4-byte block of the cell to CAD_Up, which stores it in CAD_Store using the address of the next cell assembly buffer prepared previously. However, CAD_Up skips the first 8 bytes, which are reserved for the routing header, before it stores the first

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4-byte block. A 4-bit register pointing to the lower address of where the next 4-byte block should go is updated and is used as a displacement pointer from the cell buffer address.

f.CAD_Up writes source port (SP) in RH. When the cell is completely assembled in the CAD_Store, CAD_Up puts the cell buffer address in a general queue, to allow for cell assembly ending almost at same time (one cycle of SFE_Up/CAD_Up interface). Each cell will then be dequeued on a first-in/first-out basis from the general queue, and CAD_Up sends a copy of the first 4-byte block and the source port (SP) to CAP_Up. CAD_Up prepares the address of the next assembly cell buffer for this port. The address is determined from the port number, which indicates a register pointing to where these 4-bytes should be placed. This register is also updated.

2.Prepare the routing header (RH).

a.The first 4-byte block of a cell is the first 4 bytes of the ATM cell header which contains the VPI/VCI. When CAP_Up receives the first 4-byte block with SP it now has all the information it needs to identify a particular connection: SP, VPI and VCI. From these three values, CAP_Up determines the inbound leaf control block address (LCBAup), which is the pointer to the leaf control block (LCB) for this connection.

b.The LCB contains the target blade (TB). TB, LCBAup and source blade (SB), and RB/NRB connection parameter are given to CAD_Up to be written to the header of the internal cell in CAD_Store.

CAP_Up knows the address of the beginning of this cell, so that the address is also given to CAD_Up to ensure that the information is written in the correct place in CAD_Store. In the case of an unknown SP/VP/VC, the cell is released by CAP_Up by sending to CAD_Up the cell buffer address, which can be used for another data movement.

CAP_Up also performs smart discard on NRB AAL5 frame flows, which purges cells on an AAL5 frame basis in the case of NRB node congestion.

3.Place the cell in the queue.

The cell is put by CAD_Up into the appropriate output queue (with the RB/NRB indication) so that prioritization of traffic can occur. There is an RB queue and an NRB queue.

The cell is now ready to be switched.

4. Switch the cell.

This step depends on whether or not the IBM 8285 has an expansion unit. In other words, whether the switching is done by the CAP/CAD or by the switch chip. When the IBM 8285 is installed without the expansion unit, the switching is done as follows:

a.The connection between CAD_Up and CAD_Down has been enabled because the IBM 8285 does not have the switch chip.

b.The cell is switched from CAD_Up to CAD_Down immediately.

When the IBM 8285 is installed with the expansion unit, the switching is done as follows:

a.When the expansion unit installed, all connections between the switch chip and the CAP/CADs are enabled. And then, the direct

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connection between CAD_Up and CAD_Down in the base unit is disabled.

b.When the switch chip indicates to CAD_Up to give the next cell, CAD_Up gives the first cell from the appropriate queue based on its priority mechanism (RB over NRB Queue)

c.The cell is delivered to the switch chip, and the pointers of that queue are updated.

d.The switch chip switches the cell based on TB.

5.Receive the cell into the target blade.

a.CAD_Down has prepared a location in advance for the next cell.

b.CAD_Down receives the cell into CAD_Store in the general queue.

c.CAD_Down dequeues the cell and sends CAP_Down a copy of the RH, which contains the LCBAup and the source blade.

6.Place the cell in the correct output queue and prepare it for transfer to SFE_Down.

a.Using SB and LCBAup, CAP_Down determines LCBAdown. LCBAdown points to the LCB for the connection in the outbound blade. The LCB has VPI/VCI out, target port (TP), RB/NRB and Multicast indication. There is also part of the LCB in a shadow zone in CAD_Store for performance reasons.

b.LCBAdown TP, NRB/RB, and Multicast indications from the LCB are given to CAD_Down.

CAD_Down queues the cell in the corresponding target port queue (one RB and one NRB per port) with the indication received from CAP_Down and prepares it for transfer to SFE_Down.

7.Prepare and send a new ATM cell.

a.When SFE_Down asks for the next cell of a port, CAD_Down moves the contents of LCBshadow, which has VPI/VCI out and the type of swapping (SWAP_TYPE) to be performed, plus the 52-byte cell to SFE_Down.

b.SFE_Down modifies the header based on SWAP_TYPE. SWAP_TYPE indicates if only the VP needs to be swapped, if both the VP and VC need to be swapped or neither need to be swapped. The PTI field is always retrieved from the incoming header.

c.SFE generates HEC.

d.SFE presents the cell to the specific interface.

Point-to-Multipoint Routing

In a point-to-multipoint (multicast) connection, the process is very similar. Steps remain the same right up until the cell is ready to be switched. The TB field actually indicates that this cell is part of a multicast connection by having the first bit of TB set to 1. The other 7 bits form the multicast ID (MID). In a point-to-point connection, the first bit is set to 0 and the other 7 bits indicate the target blade.

1.Switch the cell.

This step depends on the IBM 8285 has a expansion unit or not. In other words, the switching is done by the CAP/CAD or the switch chip. When

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the IBM 8285 is installed without the expansion unit, the switching is done as follows:

a.The cell is switched from CAD_Up to CAD_Down immediately as well as the case of point-to-point connection. The CAP_Up does not recognize the multicast ID.

When the IBM 8285 installed with the expansion unit, the switching is done as follows:

a.The switch chip recognizes that the TB is actually a Multicast ID; thus, using the MID as a pointer, it looks at its switch multicast tree table to get 16 bits. Each bit corresponds to a blade. If the bit is on, then that blade is part of the multicast tree.

b.The switch chip switches the cell to the target blades based on the multicast tree table.

2.Receive the cell into the target blade.

This step is the same as in a point-to-point connection described earlier.

3.Place the cell in the correct output queue and prepare for transfer to SFE_Down.

a.Using SB and LCBA, CAP_Down determines LCBAdown. Since this is a multicast connection, LCBAdown actually points to a chain of LCBs. Each LCB in the chain represents the branches on the multicast tree on this blade. Each LCB in the chain has VPI/VCI out, SWAP_TYPE and target port (TP) and last multicast (Last_MC) indication. There is also a shadow of the LCB chain in CAD_Store for performance reasons.

b.The same steps as in the unicast case apply. But when the cell has been sent to SFE_Down, the CAD_Down will re-enqueue this cell in the general queue so that CAP will reprocess this cell with the next LCB in the chain. This is done till CAP_Down finds the LAST_MC indication in the LCB.

4.Prepare and send a new ATM cell.

These scenarios assume that the appropriate tables have been assembled already by the 8285 ATM Control Point and stored in the appropriate CAP/CAD. This would be done, for instance, during the call establishment process. To communicate such information to internal devices (such as CAD, CAP, an SFE), the 8285 ATM Control Point uses a special port number, F (which is unique within the switch), and special internal cells, called guided cells, which can be discriminated from the other internal cells, called swapped cells, by its format field.

3.3 Control Point Codes

There are three types of control point microcode:

Boot Code

This resides in flash memory on the control point and is the first thing that executes after a power-on or reset. It contains initialization, diagnostics and support for download out-of-band commands. This code executes straight from flash memory and is normally used to load the operational code.

Operational Code

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This code is also on the control point and is executed once the boot code has finished. There are two copies of the code stored in the flash memory. One of these copies is identified as current and is loaded into RAM during the initialization process. This code is executed from RAM. The second copy of the operational code allows new operational code to be loaded into the control point while the control point is running, and then swapped (which resets the ATM subsystem) when it is less disruptive to network operations.

FPGA Code

This code configures the various internal chips on the IBM 8285 base unit so that they perform their desired ATM functions. There are two copies of the FPGA code stored in flash memory. One of these copies is identified as current code. The current code is loaded into the internal chips of the appropriate components during the initialization process. The second copy of the FPGA code allows new FPGA code to be loaded while the IBM 8285 is operational, and then swapped (which resets the ATM subsystem) when it is less disruptive to network operations.

The following sections describe the code levels that are currently shipped, are announced, or are available in the future.

3.3.1 Control Point Levels

Table 1 lists the levels of control point code that are currently available for the 8285 switch.

Table 1. Control Point Levels Summary of the IBM 8285 Nways ATM Workgroup Switch

Control Point

Available

Highlights

Level

 

 

 

 

 

V1.0.0

March 1996

Initial release

 

 

 

V1.0.1

April 1996

Fixed some problems in initial release

 

 

 

V1.2.0

July 1996

TR LEC, EU, and 8260 modules support 1

 

 

 

V1.3.0

October 1996

New 8260 module support 2

 

 

 

V1.4.0

October 1996

Connection capacity increased, Variable VPC/VCI, ABR flow

 

 

control and PVC multipoint support 3

 

 

 

Notes:

1 Except A-CPSW, MSS Server and 8271/8272 modules

2 A3-MB155 module

3 ATM firmware upgrade kit required

These control point microcode levels (except the obsolete ones) are available on the Internet and can be downloaded via the Web or by FTP. And the code can be downloaded into the IBM 8285 either out-of-band via a SLIP-connected workstation, or inband via an FTP file transfer. For more information about how

to get and download the code, refer to 6.4, ªMicrocode/Picocode Considerationsº on page 110.

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3.3.2 Control Point V1.2

The Control Point V1.2 has been available since July 1996. It contains the operational code V1.2.0, the boot code V1.2.0 and FPGA 3. The FPGA is optional but highly recommended.

The highlights of new and enhancement functions are as follows:

Token-Ring (IEEE 802.5) LAN Emulation Client (LEC) Support

The previous levels allowed the inband monitoring of the IBM 8285 in a Classical IP environment as well as in Forum-Compliant LAN Emulation (Ethernet / IEEE 802.3). This support has been extended to Token-Ring (IEEE 802.5) Forum-Compliant LAN Emulation.

Expansion Unit and 8260 ATM Modules Support:

This level supports the IBM 8285 Expansion Unit and IBM 8260 ATM modules as follows:

ATM 4-Port 100 Mbps MIC Fiber Module

ATM 4-Port 100 Mbps SC Fiber Module

ATM 2-Port 155 Mbps Flexible Media Module

ATM 12-Port 25 Mbps UTP Concentrator Module

ATM 4-Port Ethernet/TR Bridge Module

ATM WAN Module

Note

When this level became available, it supported all IBM 8260 ATM media and bridge modules then announced. However, there are the following modules are currently announced and not supported by the IBM 8285 expansion unit:

MSS Module

8271/8272 LAN Switch Modules

MIB Enhancement (MIB 1.5)

The IBM private MIB for the IBM 8285 is enhanced corresponding to the other enhancements.

3.3.3Control Point V1.3

The Control Point V1.3 has been available since October 1996. It contains the operational code V1.3.0 and the boot code V1.3.0. No FPGA is included in this level.

The highlights of new and enhancement functions are as follows:

New 8260 ATM Modules Support

In addition to the control point level V1.2, this level supports the new IBM 8260 ATM modules as follows:

ATM 3-Port 155 Mbps LAN Concentration Module

MIB Enhancement (MIB 1.6)

The IBM private MIB for the IBM 8285 is enhanced corresponding to the other enhancements.

30 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

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3.3.4 Control Point V1.4

The Control Point V1.4 has been available since October 1996 as well as the V1.3. It contains the operational code V1.4.0, the boot code V1.4.0 and FPGA code 0B40 and 0C10. The FPGA code 0C10 is for the ATM 3-port 155 Mbps LAN Concentration module, ATM 12-port 25 Mbps UTP Concentrator module and for the 8285 Base Unit. The FPGA code 0B40 is for the others.

This level is also called as the ATM Firmware Upgrade Kit (MES 5099) and the FPGA upgrade is mandatory. The boot and operational code V1.4.0 supports several functions with new FPGA codes in addition to the functions provided by V1.3.0 of those codes. The FPGA codes for all available ATM modules are contained in the ATM Firmware Upgrade Kit.

The highlights of new and enhancement functions are as follows:

Increase of Number of Connections

For all ATM media modules currently announced, the number of bidirectional connections is increased from 992 to 4,064 per ATM blade. However, the maximum number of connections per an IBM 8285 is 2,048 due to the limitation of its control point.

Variable Range of VPI/VCI Values Support

The ITU-T define the ATM cell format and the virtual path identifier (VPI) and virtual channel identifier (VCI) have 8 bits (VPI value comprised between 0 and 256) and 16 bits (VCI value comprised between 0 and 65536). However, in actual campus network, the full address range should not be used and the UNI specification allows you to restrict the number of active VPI and VCI bits. The IBM 8285 supports a 14 or 12-bit address range for VPI/VCI depending on which port is used. And prior to the control point V1.3, the range was fixed to a 2-bit VPI (0 through 3) and 10-bit VCI (0 through 1023) for the 25 Mbps ports (base unit and 25Mbps module) and 4-bit VPI (0 through 15) and 10-bit (0 through 1023) for the other ports. The control point V1.4 supports variable range of VPC/VCC. This function allows you to have more virtual path connections (VPCs) or virtual channel connections (VCCs) than previous levels along with the customer requirement. The range supported on an ATM port depends on which port is used.

For the 25 Mbps ports:

One of the following three patterns of range can be selected:

-VPI/VCI: 0 bit/12 bits (VPI=0, VCI=0 through 4095)

-VPI/VCI: 2 bits/10 bits (VPI=0 through 3, VCI=0 through 1023)

-VPI/VCI: 4 bits/8 bits (VPI=0 through 15, VCI=0 through 256)

For the other ports:

One of the following three patterns of range can be selected:

-VPI/VCI: 0 bit/14 bits (VPI=0, VCI=0 through 16383)

-VPI/VCI: 4 bits/10 bits (VPI=0 through 15, VCI=0 through 1023)

-VPI/VCI: 6 bits/8 bits (VPI=0 through 63, VCI=0 through 256)

In addition, the network administrator can define upper limits for VPI/VCI values to meet specific ranges supported by some ATM UNI devices. The ATM Forum-Compliant UNI stations inform the ATM switch about the supported values of VPI/VCI. In case a station fails to do so, this may

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prevent interworking with the IBM ATM switches. This function solves this problem by allowing the the network administrator to set the VPC/VCC range on a given ATM port on the ATM switch, thereby enabling the interworking with non-compliant devices. For example, you can restrict the VPI value equal to 0 and VCI value comprised between 0 and 63 by specifying 0/6 as the VPI/VCI.

Note

If you change the VPI/VCI range for the SSI or NNI port, you must specify the same value on both ends.

ABR Flow Control Support

On the ATM 12-port 25 Mbps UTP Concentrator module, the ATM 3-port 155 Mbps LAN Concentration module, and on the 12-port 25 Mbps base unit, the end user can add the ATM Forum-compliant available bit rate (ABR) flow control through Explicit Forward Congestion Notification Indication (EFCI) marking. When congestion occurs due to excessive traffic flow, the IBM 8285 and 8260 modules can now mark the EFCI bit in the ATM cells to indicate a congestion condition asking the destination station to notify the source device to reduce its traffic.

Increase Buffer Size

When multiple ATM sources try to send traffic over one link (for instance the one to which a server is attached), using UBR or ABR class of service, congestion conditions might occur because the aggregate traffic exceeds the capacity of the LAN traffic over ATM. By having a larger buffer size (8,000 cells) the A12-MB25 and A3-MB155 modules are able to absorb bursts of traffic of longer duration, thereby delaying the trigger of the congestion control mechanism, such as Early Packet Discard. This improves the overall response time and relieves end systems from extra frame retransmissions.

PVC Multipoint Support

In addition to the existing support of point-to-multipoint SVCs, this introduces the smart PVC point-to-multipoint function. Point-to-multipoint trees can be defined now with either fixed permanent virtual paths (PVPs) or fixed permanent virtual channels (PVCs). You only need to define the parameters (VP or VP/VC values) for the root of the tree and the leaves, without any definition for intermediate switches. In case of failure on these intermediate switches, the connections are automatically re-established.

New 8260 ATM Modules Support

In addition to the control point level V1.2, this level supports the new IBM 8260 ATM modules as follows:

ATM 3-Port 155 Mbps LAN Concentration Module

MIB Enhancement (MIB 1.6)

The IBM private MIB for the IBM 8285 is enhanced corresponding to the other announcements.

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3.4 ATM Backplane / Expansion Unit Connection

As described in Figure 9 on page 18, there are several ATM buses to connect each component of IBM 8285. The buses between CAP/CADs or CAP/CAD and the switch chip are called as the ATM backplane. In the IBM 8285, the ATM backplane is extended to the connection between the base and expansion unit. When the IBM 8285 is installed with the expansion unit, they are connected by a special cable, called the expansion interface cable, which has 68 pins. On the other hand, as described in some documents, such as the IBM 8260 As a Campus ATM Switch, all ATM modules have 120 pins for backplane connection. The difference comes from the number of modules supported by the IBM 8285 and the IBM 8260 whether or not it supports the redundant switch configuration. Except for the redundant switch function, both of the IBM 8285 and IBM 8260 ATM backplanes are fully equivalent functionally to an ATM blade.

You can find the pin layout of the IBM 8285 expansion interface in the appendix of the IBM 8285 Nways ATM Workgroup Switch: Installation and Users Guide. For more information about the IBM 8260 ATM backplane, refer to IBM 8260 As a Campus ATM Switch, SG24-5003.

Table 2 shows the characteristics of typical buses implemented in the IBM 8285.

Table 2. ATM Buses Implemented in the IBM 8285 Nways ATM Workgroup Switch

Bus Location

Bus Speed

 

 

CAD_Up and CAD_Down (ATM backplane in the base unit)

256 Mbps (32 MHz x 8 bit

 

parallel)

 

 

CP SFE and 25 Mbps HS.SFE_Up/Down

256 Mbps / FDX 1

 

 

25 Mbps HS.SFE_Up/Down or 155 Mbps SFE_Up/Down and

512 Mbps (16 MHz x 32 bit

CAD_Up/Down

parallel) / FDX 1

 

 

CAD_Up/Down and the switch chip (ATM backplane across the

256 Mbps / FDX 1

expansion unit)

 

 

 

Note

1 FDX means each up (inbound) and down (outbound) works simultaneously and the maximum capacity should be double (256 Mbps/FDX : 512 Mbps).

As described above, the internal bandwidth for each blade should be 256 Mbps. However, we have to consider that the IBM 8285 uses a 64-byte internal cell instead of a 53-byte ATM standardized cell. As a result, the available ATM bandwidth for the ATM cell transfer should be decreased from the internal bandwidth, 256 Mbps per blade, to 212 Mbps (256 Mbps x 53/64) per blade by the overhead of the internal cell header/trailer.

3.5 LAN Emulation Server Functions

The IBM 8285 integrates a Forum-compliant LAN Emulation Server (LES) and

Broadcast and Unknown Server (BUS) functions in the control point. The

LES/BUS functions are performed with or without external a LAN Emulation

Configuration Server (LECS).

The IBM 8285 can support up to two sets of the LES/BUS functions with any combinations of the types of LAN emulation, token-ring (IEEE 802.5) and Ethernet

Chapter 3. Functional Overview of the IBM 8285 33

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(IEEE 802.3). The maximum number of the LAN Emulation Clients (LECs) is 128 regardless the number of the LES/BUS, so it should be the sum of the LECs supported by the IBM 8285 when two LES/BUS are used.

The LES/BUS gives an impact on CP performance when running so that the processor and memory are mainly shared between signaling, BUS and routing. However, it is designed to prevent the CP traffic from the delay and buffer accumulation by assigning lower priority to the broadcast traffic.

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Chapter 4. IBM 8285 ATM Modules

This chapter describes the various functions and features that are available on 8285 ATM modules.

4.1 Modules Currently Available for the 8285 ATM Subsystem

The current ATM modules for the IBM 8285 are:

ATM 12-Port 25 Mbps UTP Concentrator Module

ATM 2-Port 155 Mbps Flexible Media Module

1-port ATM 155Mbps Multi-mode Fiber I/O card

1-port ATM 155 Mbps Single-mode Fiber I/O card

1-port ATM 155 Mbps UTP/STP I/O card (RJ-45)

1-port ATM 155 Mbps STP I/O card (DB9)

ATM 3-Port 155 Mbps LAN Concentration Module

1-port ATM 155Mbps Multi-mode Fiber I/O card

1-port ATM 155 Mbps Single-mode Fiber I/O card

1-port ATM 155 Mbps UTP/STP I/O card (RJ-45)

1-port ATM 155 Mbps STP I/O card (DB9)

ATM 4-Port 100 Mbps MIC Fiber Module

ATM 4-Port 100 Mbps SC Fiber Module

Video Distribution Module

ATM 4-Port TR/Ethernet Bridge Module

ATM WAN Module

1-port E3 I/O card

1-port DS3 I/O card

1-port OC3 I/O card (SMF)

1-port OC3 I/O card (MMF)

1-port STM1 I/O card (SMF)

1-port STM1 I/O card (MMF)

Copyright IBM Corp. 1996

35

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4.2 Some Common Elements among the 8285 Modules

The following sections describe some of the common elements shared by the 8285 modules.

4.2.1 Maximum Capacity

All 8285 modules have a backplane capacity of 212 Mbps. In order to provide guaranteed service, the maximum configurable reserved bandwidth is 185 Mbps (85% of 212 Mbps). The non-reserved traffic will use whatever bandwidth is available, including bandwidth that is reserved but not being used.

4.2.2 Variable VPC/VCC Value Ranges

With the latest release of 8285 code (Release 1.4), the 8285 modules now support variable VPC/VCC range values. That is to say, they allow you to manage your network more precisely by allocating varying numbers of bits to the VPC and VCC portions of the header on a port-by-port basis.

Note

The VPC/VCC range must be the same on both ends of an SSI or NNI link.

With one exception, noted below, all of the modules allocate 14 bits to the VPC/VCC portion of the header, which you can allocate in one of the following ways:

Mode 0/14 (all 14 bits assigned to VCC):

V P C = 0

VCC range is 0-16383

Mode 4/10 (4 bits for VPC, 10 bits for VCC):

VPC range is 0-15

VCC range is 0-1023

Mode 6/8 (6 bits for VPC, 8 bits for VCC):

VPC range is 0-63

VCC range is 0-255

The exception to the above is the newest module, the ATM 12-Port 25 Mbps UTP Concentrator Module, which allocates only 12 bits to the VPC/VCC portion of the header, and which allows the following modes:

Mode 0/12 (all 12 bits assigned to VCC):

V P C = 0

VCC range is 0-4095

Mode 2/10 (2 bits for VPC, 10 bits for VCC):

VPC range is 0-3

VCC range is 0-1023

Mode 4/8 (4 bits for VPC, 8 bits for VCC):

VPC range is 0-15

VCC range is 0-255

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For all modules, you can define upper limits for VP/VC values at the port level to facilitate interoperability with certain ATM devices that have constraints on what values they will accept. This is done using the Set PORT command, which has a new parameter, VPI_VCI: #bits_vpi.#bits_vci.

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4.3 ATM 12-Port 25 Mbps UTP Concentrator Module

The ATM 25 Mbps UTP Concentrator Module is a single-slot concentrator module that provides low-cost access to a high-performance ATM network. It is ideal for upgrading your legacy LAN users and for providing higher performance to new users.

It has the following characteristics:

12 Forum-Compliant ATM 25.6 RJ-45 ports capable of supporting shielded and unshielded twisted pair cabling.

Supports user-to-switch, server-to-switch, and switch-to-switch connections in any combination.

Supports ATM Forum Available Bit Rate (ABR) Service using Explicit Forward Congestion Control (EFCI) marking.

Has a large 8,000 cell buffer to smooth bursts of traffic without triggering congestion control mechanisms.

Supports UNI 3.0, UNI 3.1, and UNI translation.

Expands IBM 8285 Nways ATM Workgroup Switch capacity up to 48 ports with optional 8285 Expansion Chassis (FC# 5502).

4.3.1Sample Scenarios

The ATM 12-Port 25 Mbps UTP Concentrator Module is a high-performance card that is very cost-effective for connecting high-bandwidth users and servers into a workgroup or an ATM network. In addition, it can be used to provide redundant links to a backbone or server to provide higher bandwidth and improved reliability. Figure 12 on page 39, Figure 14 on page 41, and Figure 13 on

page 40 show some ways the ATM 12-Port 25 Mbps UTP Concentrator Module can be used with the 8285 switch.

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Figure 12. ATM 12-Port 25 Mbps UTP Concentrator Module Workgroup

The first example, a workgroup configuration, shows how you might set up a very cost-effective stand-alone workgroup by merely changing adapters in the workstations and connecting them to the 8285 switch. This simple change provides up to 25 Mbps of bandwidth to the desktop for up to 48 users per 8285, and gives them access to a high-speed server.

Chapter 4. IBM 8285 ATM Modules 39

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Figure 13. 8285 Low-Cost Configuration Implementation

The second example shows a building with 8285s on floors and in the basement. The backbone and server are working at 155 Mbps. By ordering an 8285 model 00P, it is possible to create an ATM network at a very attractive price, since it provides both the base unit and 12 ATM25 workstation adapters at a special bundled price.

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Figure 14. 8285 with ATM 12-Port 25 Mbps UTP Concentrator Modules as an Access

Switch

The third example shows how you can connect the ATM25 workgroup into the backbone network to access additional high-speed resources using only the standard ATM 155 Mbps uplink. In this capacity, the 8285 makes an excellent ATM floor switch, especially when used in conjunction with the IBM 8260 Nways Multiprotocol Switching Hub as the backbone or collapse-point switch.

By implementing a second backbone link (using either the ATM 2-Port 155 Mbps Flexible Media Module or the ATM 3-Port 155 Mbps LAN Concentration Module) connected to a different switch in the backbone, you can take advantage of the additional bandwidth during normal operations, and provide availability to your workgroup even if one of the collapse-point switches fails.

Chapter 4. IBM 8285 ATM Modules 41

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4.4 ATM 2-Port 155 Mbps Flexible Media Module and ATM 3-Port 155 Mbps LAN Concentration Module

The ATM 2-Port 155 Mbps Flexible Media Module and the ATM 3-Port 155 Mbps LAN Concentration Module are single-slot concentrator modules that are ideal for high-speed connections to both local resources and to devices up to 20 Km away. They have the following characteristics in common:

Provide two or three ports, each capable of supporting a 155 Mbps

(full-duplex) connection to either a user, a server, or another switch. The traffic received from these ports will be multiplexed into the backplane connection between the ATM 155 Mbps Media Module and the

switch-on-a-chip.

Each port can support any of the following I/O cards:

Table 3.

ATM 155 Mbps Media Module Supported I/O Cards

 

 

 

 

 

 

Feature

 

Part Number

Interface

Cable

 

 

 

 

 

8800

 

58G9667

SC

Multi-Mode Fiber

 

 

 

 

 

8801

 

58G9855

SC

Single-Mode Fiber

 

 

 

 

 

8802

 

58G9856

RJ-45

UTP5/STP

 

 

 

 

 

8803

 

58G9857

DB9

STP

 

 

 

 

 

Support either SONET STS-3C or SDH STM-1 on any port at speeds of 155.520 Mbps.

STS-3c Limitations

The STS-3c implementation is a Lite implementation, which, although fully compliant with ATM Forum standards, is lacking some of the management and overhead portions of a full SONET implementation. It will interoperate with the 1-port OC3 I/O card (SMF) and the 1-port OC3 I/O card (MMF) that are installed in an ATM WAN Module. However, neither the 1-port ATM 155 Mbps Single-mode Fiber I/O card nor the

1-port ATM 155 Mbps UTP/STP I/O card (RJ-45) are suitable for direct connection to a public bearer service other than dark fiber. In addition, there may be incompatibilities with certain adapters that expect a full SONET implementation.

STM-1 Limitations

The STM-1 implementation is a Lite implementation, lacking some of the management and overhead portions of a full SDH implementation. It will interoperate with the 1-port STM1 I/O card (SMF) and the 1-port STM1 I/O card (MMF) that are installed in an ATM WAN Module. However, neither the 1-port ATM 155 Mbps Single-mode Fiber I/O card nor the 1-port ATM 155 Mbps UTP/STP I/O card (RJ-45) are suitable for direct connection to a public bearer service. In addition, there may be incompatibilities with certain adapters that expect a full SDH implementation.

Please refer to Asynchronous Transfer Mode (ATM): Technical Overview for more information on the SONET and SDH standards.

Hot-pluggable in any slot in the 8285 Expansion Chassis.

Support UNI, SSI, and NNI on either port in any combination.

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Support UNI 3.0 and/or UNI 3.1 on all ports and will attempt to adapt to the standards of the connected device. That is to say, if a remote UNI 3.1 device needs to connect to a UNI 3.0 device connected to the ATM 155 Mbps module, the module will attempt to translate between the two at the output port.

4.4.1Differences between the 2- and 3-Port ATM Modules

Although these two modules are very similar, there are some key differences. Specifically, the ATM 3-Port 155 Mbps LAN Concentration Module has the following additional features:

Supports ATM Forum Available Bit Rate (ABR) Service using Explicit Forward Congestion Control (EFCI) marking.

Has a large 8,000 cell buffer to smooth bursts of traffic without triggering congestion control mechanisms.

4.4.2ATM 155 Mbps Media Module Traffic Management

The ATM 155 Mbps Media Module provides reserved bandwidth (RB) and non-reserved bandwidth (NRB) with the following caveats:

For RB traffic, the maximum bandwidth that can be reserved is 85% of the total throughput capacity, which is:

Port Interface: 131 Mbps (85% of 155 Mbps)

Backplane Interface: 180 Mbps (85% of 212 Mbps)

4.4.2.1 Reserved Bandwidth Constraints

In order to fairly allocate reserved bandwidth among its ports, the ATM 155 Mbps modules will enforce traffic limitations on each port that is configured for SSI, as follows:

For a single SSI link between two 8285s, the maximum bandwidth that can be reserved is 131 Mbps (85% of 155 Mbps).

If a second SSI port is configured, the amount of reserved bandwidth for the first port will be recalculated and each SSI link will be allocated 90 Mbps (50% of 180 Mbps). If the peak cell rate (PCR) in the first SSI port exceeds 90 Mbps when you try to configure the second port, the command setting for the second SSI port will be rejected since the first port could not be throttled back.

If a third SSI port is configured (on the ATM 3-Port 155 Mbps LAN Concentration Module only), the amount of reserved bandwidth for the first two ports will be recalculated and each SSI link will be allocated 60 Mbps (33% of 180 Mbps). If the peak cell rate (PCR) in either of the first two SSI ports exceeds 60 Mbps when you try to configure the third port, the command setting for the third SSI port will be rejected since the other ports could not be throttled back.

4.4.3Sample Scenarios

The ATM 155 Mbps Media Modules are high-performance cards that are ideal for connecting high-bandwidth users and servers into either a workgroup or an ATM network. In addition, they can be used to provide redundant links to a backbone or server to provide higher bandwidth and improved reliability. Figure 15 on page 44 shows how the ATM 2-Port 155 Mbps Flexible Media Module can be used as a concentrator for a high-performance workgroup.

Chapter 4. IBM 8285 ATM Modules 43

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Figure 15. ATM 2-Port 155 Mbps Flexible Media Module High-Performance Workgroup

In this scenario, six users are connected to the 8285 via a high-performance ATM 155 Mbps adapter, such as the IBM Turboways ATM 155 Mbps Adapter, connected in to ATM 2-Port 155 Mbps Flexible Media Modules installed in the 8285 Expansion Chassis. This allows all six users to access the ATM 155 Mbps server, connected to the ATM 155 Mbps port on the base unit, for such bandwidth-intensive applications as CAD/CAM, video playback, etc. In addition, 12 ATM25 users can access the same high-performance ATM server for such applications as video conferencing and traditional LAN server applications.

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Figure 16. ATM 3-Port 155 Mbps LAN Concentration Module with Redundant Backbone

Links

Figure 16 shows how you can use the ATM 3-Port 155 Mbps LAN Concentration Module to connect a high-performance workgroup into the backbone network to access additional high-speed resources. In this case, up to eight users, using workstations with high-performance ATM 155 Mbps adapters, such as the IBM Turboways ATM 155 Mbps Adapter, are connected in to ATM 3-Port 155 Mbps LAN Concentration Modules installed in the 8285 Expansion Chassis. This enables each user to access resources across the ATM backbone network. By providing redundant backbone links, preferably to separate backbone switches, the ATM 3-Port 155 Mbps LAN Concentration Module also provides aggregate backbone access bandwidth as high as 310 Mbps and ensures availability to the workgroup should one of the links fail. Up to 12 ATM25 users can also take advantage of this increased bandwidth and availability.

Whether as a workgroup solution or as a backbone solution, the ATM 2-Port 155 Mbps Flexible Media Module and the ATM 3-Port 155 Mbps LAN Concentration Module meet the needs of bandwidth-intensive applications, with the ATM 3-Port 155 Mbps LAN Concentration Module offering more ports, a lower price/port, and additional buffering to handle bursty traffic.

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4.5 ATM 4-Port 100 Mbps MIC Fiber Module and the ATM 4-Port 100 Mbps SC Fiber Module

The ATM 4-Port 100 Mbps MIC Fiber Module and the ATM 4-Port 100 Mbps SC Fiber Module are single-slot concentrator modules that are identical except for they have MIC and SC connectors, respectively. They have the following characteristics:

Hot-pluggable in any slot in the 8285 Expansion Chassis.

Each module provides four taxi ports, each capable of supporting 100 Mbps (full-duplex). The traffic received from these ports will be multiplexed into the backplane connection between the A4-FB100 module and the

switch-on-a-chip.

Support for workstation connections (UNI) up to 2 km from the 8285.

Support for a connection between two A4-FB100 ports (SSI/NNI) up to 3 km.

4.5.1Sample Scenarios

The 4-port 100 Mbps modules are high-performance cards that are very

cost-effective for connecting high-bandwidth users and servers into a workgroup or an ATM network. In addition, they can be used to provide redundant links to a backbone or server to provide higher bandwidth and improved reliability.

Figure 17 and Figure 18 on page 47 show some ways the 4-port 100 Mbps modules can be used with the 8285.

Figure 17. ATM 100 Mbps MIC/SC Fiber Module Workgroup Configuration

The first example, a workgroup configuration, shows how you might set up a very cost-effective high-performance stand-alone workgroup, providing up to 100 Mbps bandwidth to as many as 16 power users, 25 Mbps of bandwidth to as

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many as 12 ATM25 desktops, and give them all 155 Mbps access to an ATM server. When used in conjunction with IBM′s Turboways 100 Mbps ATM Adapters on the workstations, performance can meet or exceed some 155 Mbps adapter/switch combinations.

Figure 18. ATM 100 Mbps MIC/SC Fiber Module with Redundant ATM Backbone Links

The second example, above, shows how you can connect the high-performance workgroup into the backbone network to access additional high-speed resources. By implementing a second backbone link connected to a different switch in the backbone, you can provide additional bandwidth for your users and enhance the network′s availability to your workgroup even if one of the collapse-point switches fails.

Chapter 4. IBM 8285 ATM Modules 47

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4.6 Video Distribution Module

The Video Distribution Module is a double-slot video concentrator module that can be used to provide low-cost, high-quality, video distribution to standard TV monitors. It has the following characteristics:

Eight independently addressable MPEG-2 decoder ports. Each port can support an MPEG-2 video stream encoded at data rates of 1.5-15 Mbps simultaneously.

Eight separate audio and video output connections:

Video: composite baseband NTSC (EIA Standard RS-170A) or PAL (in Release 1.1):

-Video Resolutions:

SIF: 352x240 pixels (NTSC)

HHR or Half-D1: 352x480 pixels (NTSC)

CCIR-601 or Broadcast: 704x480 pixels (NTSC)

Comparable PAL resolutions

Audio: stereo, balanced or unbalanced

Supports MPEG-2 Main Level, Main Profile (4:2:0) video and MPEG-1 audio.

Supports MPEG-2 Elementary Stream or MPEG-1 Elementary Stream encapsulated in an MPEG-2 Transport Stream at speeds of up to 15 Mbps.

Supports a Single Program Transport Stream (that is, one video and one audio program).

Supports Closed Caption data and Extended Data Services information in accordance with EIA 608: Recommended Practice for Line 21.

Supports ATM for PVC and SVC Connections using UNI 3.1.

Can receive video input from any ATM device that can access the 8285 switch via the the ATM network.

Supports frame synchronization using GENLOCK inputs.

Functions as an H.310 AAL-5 Receive-Only Terminal (ROT). H.310 is an ITU standard for broadcast-quality audiovisual communication over broadband networks using MPEG-2 video over high-speed ATM networks. The standard includes subparts such as:

H.262 (MPEG-2 video standard)

H.222.0 (MPEG-2 Program and Transport Stream)

H.222.1 (MPEG-2 streams over ATM)

Various audio compression standards

Can be monitored, but not configured via the 8285 ATM Control Point.

4.6.1MPEG Fundamentals

MPEG-2 is an International Telecommunication Union (ITU) standard for digitizing, compressing, and multiplexing video and audio information. The predecessor to MPEG-2 is MPEG-1, which is widely used in low-end video and PC software-based encoding and decoding environments. MPEG-1 is a desktop

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quality, low bandwidth, and low resolution standard with fixed limited rates. MPEG-2 expands upon MPEG-1 in all directions:

Higher quality (at the expense of higher bandwidth requirements)

Higher resolutions (up to HDTV levels)

Tremendous flexibility in compression rates.

MPEG-2 provides the standard for high-quality motion video compression. It is accepted by all segments of the entertainment, broadcasting, and video editing industry.

4.6.1.1 MPEG-2 Data Streams

MPEG-2 allows for the multiplexing of many independent audio and video streams (called Elementary Streams) into a System Stream, with synchronization information and audio/video correlation information.

There are two types of system stream:

1. Program data stream

This is suitable in environments where reliable storage is ensured.

2. Transport data stream

This is designed to transmit audiovisual content over networks.

The MPEG-2 transport data stream carries video and audio in the same data stream within separate fields. All video and audio material is stamped with presentation time stamps at the time of encoding. These time stamps are synchronized during the decoding process. This ensures synchronization of data without perceivable jitter.

4.6.1.2 Multiplexing and Synchronization

MPEG-2 defines a system layer that provides the ability to multiplex and synchronize multiple video and audio streams, and other private data. The system layer includes clocking information between the encoder and decoder. Even when an MPEG-2 stream is stored, the decoder may read the clock values to accurately recreate the motion picture.

The system layer also removes storage and transmission dependencies from MPEG-2. Since the system layer is self-clocking, MPEG-2 does not require synchronized transmission lines. Error checking fields add robustness to the transmission layer.

In comparison, there is no standardized system layer for M-JPEG. Therefore, it must record and transmit video and audio separately. The lack of a standard prevents M-JPEG encoded material from being freely exchanged. It cannot be recorded for future playback due to the absence of built-in timing information. M-JPEG requires a synchronous transmission line, that is, a more expensive communications network.

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4.6.1.3 Motion Interpretation and Improved Compression

MPEG-2 interprets motion between successive images and takes advantage of motion to improve compression while sustaining the same level of perceived image quality. The MPEG-2 motion interpretation uses a combination of two kinds of frames to do this:

An anchor frame:

Intra-Frame (I-Frame):

-Only exploits spatial redundancy to compress information within the frame

-Contains all information to reconstruct the image; does not depend on another frame

A difference frame, which can be either:

Predictive Frame (P-Frame):

-Exploits temporal and spatial redundancy to compress video frame

-Must reference a previous anchor frame to reconstruct the image

-Can be anchors to other P or B frames

Bidirectionally Predictive Frame (B-Frame)

-Exploits temporal and spatial redundancy to compress video frame

-Must reference an anchor frame

-Cannot be an anchor to another frame

A typical encoded frame sequence might look like the one in Figure 19 on page 51.

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Figure 19. Typical MEPG-2 Picture Sequence Showing Picture Types

Since the anchor frame is sent only intermittently, and only changes are sent for the intervening frames, significant bandwidth savings can be realized, with minimum degradation of picture quality. It should be noted, however, that response time may be unacceptably affected in some situations when using full IPB compression. This can be remedied by using just I and P frames, resulting in similar delays to M-JPEG but requiring much less bandwidth.

4.6.1.4 Audio Compression

The MPEG-2 system multiplex layer allows for various audio compression standards to be used, and the definition of a standard compression scheme ensures compatibility between vendors. In comparison, M-JPEG does not include an audio standard. Audio is transmitted separately from the video.

4.6.1.5 MPEG Summary

MPEG-2 is superior to M-JPEG because of its ability to multiplex and to synchronize, to interpret motion and to provide improved compression, and to transport multiple different audio compression data streams.

Table 4 on page 52 provides a convenient comparison of the two technologies.

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Table 4. Video Distribution Module Comparison of MPEG-2 and Motion-JPEG

Feature

MPEG-2

 

M-JPEG

 

 

 

System Layer

Provides audio and video

No system layer, that is,

 

synchronization.

no standard

 

 

 

synchronization method.

 

 

 

 

Record on Servers

Yes

 

Must record video and

 

 

 

audio separately, leading

 

 

 

to synchronization

 

 

 

problems.

 

 

 

 

Motion Compression

Yes

 

No

 

 

 

 

Standard Auto

Yes

 

No

Compression

 

 

 

 

 

 

 

Compression Algorithm

DCT

 

DCT

 

 

 

MPEG-1 Compatibility

System layer can carry

No

 

MPEG-1. MPEG-2

 

 

equipment downward

 

 

compatible with MPEG-1.

 

 

 

 

 

Private Data for Closed

Yes

 

No

Captioning

 

 

 

 

 

 

 

Bandwidth Requirements

I-Frame

Less

20 Mbps

for High Quality Video

 

than 18

 

 

 

Mbps.

 

 

I + P Frame

Less

 

 

 

than 12

 

 

 

Mbps.

 

 

IPB Frame

Less

 

 

 

than

 

 

 

6-8

 

 

 

Mbps.

 

 

 

 

ATM Compatibility

MPEG-2 Transport

Requires circuit-switched,

 

Streams can be carried

constant bit rate (AAL1)

 

over AAL5 and can take

services for accurate

 

advantage of variable bit

voice and video

 

rate services.

 

synchronization.

 

 

 

Standardization

MPEG-2 video and

Video conferencing and

 

MPEG-1 audio encoding

transmission using

 

are standard.

H.310

M-JPEG is not

 

encompasses MPEG-2

standardized.

 

and defines operational

Proprietary

 

specifications for MPEG-2

implementations cause

 

over ATM video

interoperability problems.

 

conferencing.

 

 

 

 

 

 

4.6.2 Configuring the Video Distribution Module

The Video Distribution Module is a relatively simple module to configure since it is merely a target for an ATM stream from another source. The process is as follows:

Enable the VDM port as a UNI interface: In the following example:

The second port of the VDM for our video output is set.

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VPI 4 and VCI 10 values are used.

UNI signalling is set.

Flow control is disabled.

ILMI handshaking is disabled, forcing UNI 3.1 signalling.

 

 

 

 

 

 

 

 

 

8285>

set

port

3.2

disable

 

 

 

 

8285>

set

port

3.2

enable vpi_vci:4.10 uni flow_control:off ilmi:off_sig_3_1

 

 

 

 

Configure one PVC between the VDM port and the video source port, either local or remote, using the SET PVC command:

 

 

 

 

 

SET PVC local_slot.port pvc_id remote_slot.port remote_hub_number path_type

 

 

 

 

local_vpi remote_vpi bw_alloc bandwidth

 

 

 

 

 

 

 

 

local_slot.port pvc_id remote_slot.port remote_hub_number

path_type local_vpi

The slot and port number for a local end of the PVC.

This allows you to define multiple PVCs per port.

The slot and port number for the other end of the PVC.

The hub number (13th byte of the ATM address) of the other hub. Can match the local hub number for local PVCs.

Specifies the type of virtual path connection.

The vp.vc value for the local end of the PVC. See Table 5 for allowable values.

remote_vpi

The vp.vc value for the other end of the PVC. See

 

Table 5 for allowable values.

bw_alloc

The bandwidth allocation algorithm to be used:

 

BEST_EFFORT

 

RESERVED_BANDWIDTH

bandwidth

The amount of bandwidth to allocate, if bw_alloc has

 

been set to RESERVED_BANDWIDTH.

Table 5. VC Values by Port for VDM Module ( V P = 0 )

Port

First

Second

Third

Fourth

Fifth

Sixth

Seventh

Eighth

 

 

 

 

 

 

 

 

 

VC

32

33

34

35

36

37

38

39

Value

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

With the following command, the video source, an IBM 8300 Video Access Node is directly connected to the 155 Mbps port on the base unit.

 

 

 

 

 

8285>set pvc 1.13 1 3.2 02 channel 0.33 0.33 best-effort

 

 

 

 

 

 

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Reminder

Remember that the vpi.vci pairs that you specify must match those configured in the devices at each end of the PVC. In this case, the VDM forces values of 0.32, 0.33, etc., but your source device must be configured to match the vpi.vci values that you configured above.

4.6.3 Sample Scenarios

The Video Distribution Module is designed to provide cost-effective distribution of video and audio programs, either real-time or from a server, to either a workgroup or an ATM network.

It is ideal for such applications as distance learning, online education, and real-time news updates. Figure 20, Figure 21 on page 55, and Figure 22 on page 56 show some ways the Video Distribution Module can be used with the 8285 switch

Figure 20. Video Distribution Module Workgroup Configuration

The first example, a workgroup configuration, shows how you might set up a very cost-effective stand-alone workgroup, providing video distribution from a video server to a group of users (with video connections) and/or TV monitors.

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Figure 21. Video Distribution Module for Campus Video Distribution

The second example shows how you can connect the workgroup into the backbone network to access additional video resources such as TV feeds and video servers, such as the IBM 8300 Video Access Node.

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Figure 22. Video Distribution Module with ATM WAN for Enterprise Video Distribution

The third example, shows how you might use the VDM module with the ATM WAN Module to provide access to video resources throughout the enterprise using publicly available ATM WAN services, accessed with the ATM WAN Module at speeds from E3 to OC-3/STM-1.

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4.7 ATM 4-Port TR/Ethernet Bridge Module

The ATM TR/Ethernet Bridge Module is a two-slot module that functions as a multiport bridge providing a simple way to connect shared media LAN segments to a high-speed ATM backbone. This is an ideal way to begin a migration to an ATM backbone, especially for those customers running flat or bridged networks today, since it is completely transparent to your shared media users.

The main features of this module are:

Provides four external ports for interconnection to either Ethernet (IEEE 802.3 and DIX V2) or token-ring (IEEE 802.5) LANs. This module does not allow the mixing of various LAN types.

Provides media-speed bridging between all four LAN ports even

when configured for full-duplex token-ring.

Provides a single UNI 3.0-compatible ATM interface to the ATM backplane of the 8285 Expansion Chassis.

The ATM port supports clients for either Forum-compliant LAN Emulation (LANE) or IBM LAN Emulation (IBMLE). This enables traditional LAN users connected to one of the external ports to access transparently devices (for instance, servers) on a high-speed ATM ELAN, either LANE or IBMLE.

Note

The emulated LAN must be the same type of LAN as the one used on the four LAN ports. This means that the ATM 4-Port TR/Ethernet Bridge Module cannot be used to connect Ethernet devices to token-ring devices across an ATM network. However, such connectivity can be provided when the ATM TR/Ethernet Bridge Module is used in conjunction with an ATM router such as the IBM Multiprotocol Switched Services Server

Supports standard source route bridging (SRB) when the ports are configured to use token-ring. This enables easy migration from existing token-ring backbones to high-speed ATM backbones.

Supports transparent bridging when the ports are configured to use Ethernet.

Supports 256 virtual circuits (VCs) over the ATM connection.

Supports both Generic Flow Control (GFC) and Operation and Maintenance/Flow 5 (OAM-5) to throttle traffic in a congestion situation.

Supports powerful, flexible filtering of inbound LAN traffic:

In the token-ring environment, filters can be based on:

-Hop count

-MAC address

-Ring number

-Source service access point (SAP)

-Subnetwork access protocol (SNAP)

In an Ethernet environment, filters can be based on:

-MAC address

-Source service access point (SAP)

-Ethertype

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These filters can be activated and prioritized at both the bridge level and the port level to provide even greater control over your network traffic.

Comes with an easy-to-learn, easy-to-use graphical configuration program to simplify the task of configuring and managing the bridge module.

Management of the ATM LAN Bridge module is done using SNMP. The SNMP agent within the module supports various MIBs.

Note

The SNMP agent in this module is accessible via IP over any of the ATM or LAN ports. Since the ATM port supports only LANE or IBMLE, any ATM-attached management station must support LANE or IBMLE. This implies that ATM-attached stations using Classical IP over ATM (RFC 1577) cannot communicate with this module directly over ATM. However, an ATM router, such as the IBM Multiprotocol Switched Services Server, can interconnect ELANs running CIP and LANE, and provide SNMP access at the IP layer.

4.7.1.1 LAN Ports

The ATM TR/Ethernet Bridge Module has four LAN ports that can be configured (via the configuration program) to be used either as token-ring or as Ethernet ports.

Ports 1 and 3 on the module are always accessed via an RJ-45 interface for both token-ring and Ethernet.

Ports 2 and 4 can be accessed via the following interfaces:

An RJ-45 interface that can be used by token-ring or Ethernet

An AUI interface that can be used by Ethernet only

4.7.1.2 ATM Port

The ATM port on the ATM-LAN bridge does not have an external interface and communicates with the switch-on-a-chip and the 8285 ATM Control Point via the ATM backplane in the 8285 Expansion Chassis. The ATM interface complies with UNI 3.0 specifications.

4.7.1.3 RS-232 Console Port

In addition to the LAN ports, the ATM TR/Ethernet Bridge Module has an RS-232 console port (also known as a service port). The service port enables you to connect a workstation to the ATM TR/Ethernet Bridge Module to load new configuration, microcode, etc.

Note: After the initial configuration, you can also access the ATM TR/Ethernet Bridge Module inband through LAN or ATM ports to load new configuration, microcode, etc.

4.7.2 Sample Configurations Using ATM TR/Ethernet Bridge Module

The following sections show you some examples of using the ATM 4-Port

TR/Ethernet Bridge Module.

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4.7.2.1 Local LAN to LAN Server Bridging

Figure 23 shows an example of using the ATM-LAN bridge as a means of bridging three token-ring LANs together while providing all users, including the ATM25 users, with access to a LAN server. Note the console connects to the base unit and to the bridge module; this is required for the initial configuration of the bridge module.

Figure 23. Local LAN to ATM Server Bridging

Figure 24 on page 60 shows an example of using the ATM-LAN bridge as a means of bridging three Ethernet LANs together while providing all users, including the ATM25 users, with access to both a LAN server and to an ATM-attached server for very demanding applications.

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Figure 24. Local LAN Bridging and ATM Server Access

4.7.2.2 Campus LAN Interconnect and ATM Server Access

Figure 25 on page 61 shows an example of using the ATM-LAN bridge as a means of bridging four LANs together with four LANs remotely, interconnecting them with a high-speed ATM backbone while providing all users, including the ATM25 users, with access to an ATM-attached server for very demanding applications.

Note

All LANs configured on a specific module must be of the same type, Ethernet or token-ring. Moreover, the workstations connected to that port will only be able to communicate directly with other devices supporting that same kind of LAN type, whether natively (via another ATM/LAN bridge), or via LAN emulation. This limitation can be overcome using an ATM router such as the IBM Multiprotocol Switched Services Server.

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Figure 25. Campus LAN Interconnect and ATM Server Access

4.7.3 ATM TR/Ethernet Bridge Module and LAN Emulation

The ATM TR/Ethernet Bridge Module provides connectivity between traditional LANs (token-ring or Ethernet) and ATM networks by sending LAN frames transparently over the ATM network using LAN emulation to resolve

MAC-to-ATM addresses.

The IBM LAN emulation service allows the ATM network to emulate the services of either a token-ring or an Ethernet LAN. The LAN emulation service is provided jointly by a LAN emulation server (LE server) and the LAN emulation client (LE client) software running in the device attached to the ATM network.

As an LE client, the ATM TR/Ethernet Bridge Module is able to find the correct ATM destination, to set up the connection, and to switch LAN traffic to that destination on behalf of a LAN endstation. It is self-learning, meaning that it is able to discover its ATM partners and to establish connections on an as-needed basis.

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4.7.4 Association between IP and MAC Address

The ATM TR/Ethernet Bridge Module can be reached via four LAN ports and/or one ATM port, but it has only a single IP address that is assigned to it at the time of configuration. This IP address will be associated with the first port on the ATM TR/Ethernet Bridge Module that connects to a network successfully. If more than one port is configured for the ATM TR/Ethernet Bridge Module, there will be a race condition to determine which port is associated with the IP address.

The MAC address of the port associated with the IP address will be used in the response to the ARP requests sent to the IP address of the ATM TR/Ethernet Bridge Module, regardless of the port on which the ARP request is received. If the port which is associated with the IP address of the ATM TR/Ethernet Bridge Module becomes disabled (say the cable is disconnected), the IP-to-MAC address association will remain unchanged. This means that the ATM TR/Ethernet Bridge Module will still respond to ARP requests with the MAC address of the port that was initially associated with the IP address of the ATM TR/Ethernet Bridge Module. This ensures that the ARP table entry in the stations that communicate with the ATM TR/Ethernet Bridge Module via the IP will still be valid regardless of the fact that the port with that MAC address may be down.

If the ATM TR/Ethernet Bridge Module is reset and the MAC address of another port is associated with the IP address of the ATM TR/Ethernet Bridge Module, the ARP table entry in the stations that were communicating with the ATM TR/Ethernet Bridge Module will become invalid. Those stations will not be able to communicate with the ATM-LAN Bridge module via IP until their ARP table entry is aged-out or is deleted by the user to allow the IP station to discover the new MAC address associated with the ATM TR/Ethernet Bridge Module. Therefore, if you have problems communicating with the ATM TR/Ethernet Bridge Module via IP, one of the first things that you can do is to delete the ARP entry in your IP workstation to enable it to rediscover the ATM TR/Ethernet Bridge Module via the ARP process.

4.7.5 ATM TR/Ethernet Bridge Module Configuration Utility Program

The Configuration Utility Program is a DOS/Windows-based application that enables a user to modify the ATM TR/Ethernet Bridge Module′s configuration parameters, to change the operating code, and to use minimal mode. The following is the list of the functions that can be performed using the Configuration Utility Program:

Create a bridge profile

Edit a bridge profile

View a bridge profile

Save a bridge profile to the hard disk

Delete a bridge profile from the hard disk

Send a bridge profile to the ATM TR/Ethernet Bridge Module

Retrieve current configuration parameters from an ATM-LAN Bridge Module

Load new operational parameters from an ATM-LAN Bridge Module

View vital product data (VPD) for an ATM TR/Ethernet Bridge Module

Erase the configuration for an ATM TR/Ethernet Bridge Module

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Perform a memory dump of the ATM TR/Ethernet Bridge Module

To install the Configuration Utility Program, insert the diskette that contains the program in the diskette drive in your workstation, start Windows, and select Run from the Program Manager File menu. This procedure starts the execution of the install.exe file from the diskette, which installs the Configuration Utility Program. When the installation is complete, the ATM TR/Ethernet Bridge Module configuration group will appear as an icon on the Program Manager window (see Figure 26).

Figure 26. ATM TR/Ethernet Bridge Module Configuration Window

To use the Configuration Utility Program to manage the ATM TR/Ethernet Bridge Module, the workstation running this program must be able to access the ATM TR/Ethernet Bridge Module either via the service port or through a LAN or ATM port.

To use the service port, the workstation must be directly attached to the serial EIA 232 port (labeled service on the ATM TR/Ethernet Bridge Module, see Figure 27 on page 64) and must use the Serial Line Internet Protocol (SLIP) to communicate with the ATM TR/Ethernet Bridge Module. Therefore, make sure that the TCP/IP protocol is running in the workstation, and that SLIP is correctly set up in the TCP/IP configuration.

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Figure 27. The ATM TR/Ethernet Bridge Module Service Port Connection

To access the ATM TR/Ethernet Bridge Module via a LAN or ATM port, the workstation running the Configuration Utility Program must have IP connectivity through the network (either directly or through bridges, routers, etc.) to be able to reach the ATM TR/Ethernet Bridge Module′s LAN or ATM port. In this case, the TCP/IP stack in the workstation must be configured to provide such a connectivity.

Note: At the initial startup of the ATM TR/Ethernet Bridge Module, you must use the direct connection to access the module in order to load a valid configuration. After that, you may use either direct or LAN/ATM connections to access the ATM TR/Ethernet Bridge Module for subsequent configurations.

The Configuration Utility Program provides a set of windows that allow you to configure and manage the ATM TR/Ethernet Bridge Module. Figure 28 on

page 65 shows how you can navigate between various windows provided by the Configuration Utility Program.

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Figure 28. Windows Displayed by the ATM TR/Ethernet Bridge Module Configurator

For more information about how to install and use the Configuration Utility Program, please refer to Nways 8285 ATM TR/Ethernet LAN Bridge Module: Installation and Users Guide, SA33-0361.

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4.7.6 Running and Stored Configuration Parameters

When the ATM TR/Ethernet Bridge Module is running, there are always the following two sets of parameters stored:

Running parameters

These are the parameter values that are in use by the operational code.

Stored parameters

These are the parameter values that exist in FLASH memory and are used only during the startup.

The stored parameters in the FLASH memory can be changed using the Configuration Utility Program by downloading new values for the configuration parameters. This can be done by creating a file of new parameter values (called profile) and sending this file to the ATM TR/Ethernet Bridge Module. To use new parameters as the running parameters, you need to restart the ATM TR/Ethernet Bridge Module.

Once the ATM TR/Ethernet Bridge Module is in operational mode, you can only view and change the stored parameters using the Configuration Utility Program. To view and change the running parameters, you must use an SNMP management station.

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4.8 ATM WAN Module

The ATM WAN Module is a single-slot WAN concentrator module that has the following characteristics:

Provides wide-area access to campus ATM networks at speeds ranging from E3 (34.368 Mbps) to OC3/STM-1 (155.520 Mbps), when the bandwidth management capabilities of an external ATM WAN switch are not desired.

Supports switch-to-switch and switch-to-server connections at speeds up to OC3/STM-1.

Interfaces directly to the circuit installed by your service provider.

Supports both UNI and NNI.

Supports reserved bandwidth (RB) service (QOS class 1 under UNI 3.0).

Is hot-pluggable in any available slot in the 8285 Expansion Chassis.

Supports both internal and external clocking.

Up to 3 ATM WAN Modules can be supported in the 8285 Expansion Chassis, providing up to 6 ATM WAN ports.

Features four standard interfaces:

Two backplane interfaces:

-An ATM backplane interface, which enables both data and control flows to the switch-on-a-chip and the 8285 ATM Control Point, respectively.

-A standard tri-channel interface, which provides power and other control signals.

Two I/O interfaces, which enable the attachment of any combination of the following I/O cards:

-1-port E3 I/O card (E3: 34.368 Mbps) BNC interface

-1-port DS3 I/O card (DS-3/T3: 44.736 Mbps) BNC interface

-1-port OC3 I/O card (SMF) (OC3: 155.520 Mbps) SC interface

-1-port OC3 I/O card (MMF) (OC3: 155.520 Mbps) SC interface

-1-port STM1 I/O card (SMF) (STM-1: 155.520 Mbps) SC interface

-1-port STM1 I/O card (MMF) (STM-1: 155.520 Mbps) SC interface

For each of these cards, the receive port is the left one, and the transmit port is the right one.

4.8.1 A02 WAN ATM Physical Interface Supported

The following table lists the ATM physical interfaces with WAN module interfaces supported:

Table 6 (Page 1 of 2). ATM Physical Interface Support

Layer

Rate (Mbps)

Cable

Coding

A02 WAN

 

 

 

 

Support

 

 

 

 

 

OC-48

2488

SMF

STS-48

No

 

 

 

 

 

OC-24

1244

SMF

STS-24

No

 

 

 

 

 

OC-12

622.08

SMF

STS-12c

No

 

 

 

 

 

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Table 6 (Page 2 of 2). ATM Physical Interface Support

Layer

Rate (Mbps)

Cable

Coding

A02 WAN

 

 

 

 

Support

 

 

 

 

 

STS-12c

622.08

UTP-5

(4 pairs)

No

 

 

 

 

 

OC-3/STM-1

155.52

MMF/SMF

NRZI

Yes

 

 

 

 

 

STS-3c

155.52

MMF/SMF

NRZI

Yes

 

 

 

 

 

STS-3c

155.52

UTP-5/STP

NRZI

No

 

 

 

 

 

155

155.52

MMF

8B/10B

No

 

 

 

 

 

155

155.52

STP

8B/10B

No

 

 

 

 

 

TAXI

100

MMF

4B/5B

No

 

 

 

 

 

STS-1

51.84

UTP-3

CAP-16

No

 

 

 

 

 

DS-3/T3

44.7

Coax (BNC)

NRZI

Yes

 

 

 

 

 

E3

34.4

Coax (BNC)

NRZI

Yes (Note 1)

 

 

 

 

 

E1

2.048

Bipolar-AMI

NRZI

No

 

 

 

 

 

T1

1.544

Bipolar-AMI

NRZI

No

 

 

 

 

 

25

25.6

UTP/STP

4B/5B

No

 

 

 

 

 

Note 1: Country Homologation dependency.

4.8.2 VPD Installation Considerations

Each I/O card ships with a special VPD (vital product data) PROM (Programmable Read-Only Memory) chip. Before you can install the A02 WAN module, you must attach the I/O cards and install the VPD chips. Details on the installation process can be found in IBM 8260/8285 ATM WAN Module: Installation and Users Guide. The following are a few additional considerations:

The VPD PROM sockets are next to their respective I/O cards. That is, the left (or top) socket is matched with the left I/O card, while the right (or bottom) socket is matched with the right I/O card. Arrows have been placed on both sockets pointing to their respective I/O cards.

There is only one correct way to insert the VPD PROM in each socket. This can be done by aligning the notch on the chip with the notch on the socket. However, inserting the chip backwards will not damage it; the port simply will not be able to register properly with the 8285 ATM Control Point. Reversing the chip should solve the problem.

Any VPD PROM that ships with an A02 WAN I/O card can be used with any of the other I/O cards without affecting card function. However, the card will not be listed properly in the configuration, which could be very confusing to someone managing the network. It is strongly advised that you carefully match the VPD PROM part numbers with their respective I/O cards as listed in Table 7 on page 69

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Table 7. A02 WAN I/O Card VPD Part Numbers

Card Name

Feature Code

Part Number

VPD Part Number

 

 

 

 

 

1-port E3 I/O card

8501

51H4335

 

51H4570

 

 

51H4604

 

 

 

 

(Switzerland)

 

 

 

51H4605

(Sweden)

 

 

 

51H4605

(UK)

 

 

 

51H4606

(New

 

 

 

Zealand)

 

 

 

 

 

 

 

1-port DS3 I/O

8502

51H4338

 

51H4571

card

 

 

 

 

 

 

 

 

 

1-port OC3 I/O

8503

51H4558

 

51H4572

card (SMF)

 

 

 

 

 

 

 

 

 

1-port OC3 I/O

8504

51H4673

 

51H4852

card (MMF)

 

 

 

 

 

 

 

 

 

1-port STM1 I/O

8505

51H4557

 

51H4573

card (SMF)

 

 

 

 

 

 

 

 

 

1-port STM1 I/O

8506

51H4674

 

51H4853

card (MMF)

 

 

 

 

 

 

 

 

 

4.8.3 Sample Scenario

The ATM WAN Module is designed to provide high-speed access to the WAN network for all 8285-attached devices, whether native ATM or connected via the ATM 4-Port TR/Ethernet Bridge Module.

Figure 29 on page 70 shows some ways the ATM WAN Module can be used with the 8285.

Chapter 4. IBM 8285 ATM Modules 69

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Figure 29. A Typical ATM WAN Module Configuration

The scenario depicts a possible client/server environment in which the workstation must access both servers, and in which both servers must exchange information such as files and images. The ATM WAN Module allows each site to access the common backbone network at the most cost-effective speed, from E-3 for the workstation to DS-3/T3 and even STM-1/OC-3 for the servers.

70 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

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4.9 LAN Switching Modules

Attention

The following section is included as a preview of module support that might become available in 1997.

The 8285 is capable of supporting the following LAN switching modules:

Token-Ring:

2-slot 8272 ATM/LAN Switch Module

3-slot 8272 ATM/LAN Switch Module

2-slot 8272 LAN Switch Module with the following:

-8272 LAN Switch ATM Backplane Upgrade 1

3-slot 8272 LAN Switch Module with the following:

-8272 LAN Switch ATM Backplane Upgrade 2

Ethernet:

2-slot 8271 ATM/LAN Switch Module

3-slot 8271 ATM/LAN Switch Module

2-slot 8271 LAN Switch Module with the following:

-8271 LAN Switch ATM Backplane Upgrade 3

3-slot 8271 LAN Switch Module with the following:

-8271 LAN Switch ATM Backplane Upgrade 4

Notes:

1 Becomes functionally identical to 2-slot 8272 ATM/LAN Switch Module.

2 Becomes functionally identical to 3-slot 8272 ATM/LAN Switch Module.

3 Becomes functionally identical to 2-slot 8271 ATM/LAN Switch Module.

4 Becomes functionally identical to 3-slot 8271 ATM/LAN Switch Module.

4.9.1 Description

The LAN switch modules that could be supported by the 8285 provide existing LAN users high-performance, cost-effective access to the ATM backbone as well as media-speed LAN switching for microsegmentation.

Direct ATM backplane connectivity allows segments of LAN users to be interconnected to other LANs users segment via LAN switching or high-speed ATM switching.

These modules feature the following:

Common Features:

Support media-speed transmission on all ports simultaneously, even in full-duplex mode

Support halfor full-duplex transmission on each port independently

Chapter 4. IBM 8285 ATM Modules 71

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Support port mirroring (TokenProbe or Etherprobe) whereby one port can monitor any LAN port for the purposes of connecting a LAN analysis tool

Support three switching modes to optimize performance:

1.Cut-Through Switching

In this mode, the switch reads in the address portion of the frame header, makes a forwarding decision strictly based on destination address, and forwards the header and the remainder of the packet to the destination port while the packet is still arriving. This optimizes forwarding performance, but does not filter out bad frames.

2. Store-and-Forward Switching

In this mode, the switch reads the entire packet into a buffer and performs a full CRC check on it before forwarding good packets to the destination port. This eliminates bad frames, but with a greater latency.

3. Adaptive Switching

This feature allows the switch to run in cut-through mode (for high performance and low latency) until the number of bad packets received surpasses a user-settable threshold within a given period of time. It then automatically switches to store-and-forward mode to avoid propagating bad packets. When the number of bad packets falls to acceptable levels, the switch reverts automatically to

cut-through mode. The net result is to give the highest possible performance with the least number of errors.

Provides a Virtual Switch capability that allows the switch to operate as though it were actually several (up to 8) switches. That is to say, traffic arriving on a port can only be forwarded to ports within its group. This also means that broadcasts are isolated within each virtual switch.

Support inbound MAC address filtering which allows:

-Blocking of packet based on source or the destination MAC address.

-Forwarding to specific ports based on source MAC address.

-Forcing traffic to specific ports based on the destination MAC address.

Token-Ring Features:

Supports 8 shielded TRN UTP/STP RJ45 lobe ports using either UTP category 3,4, or 5 cabling, or STP cabling.

Note

These ports do not support RI or RO connections. Use the 2-Port Fiber RI/RO UFC to handle RI or RO connections.

Have either two UFC slots (2-slot modules) or four UFC slots (3-slot modules), which can contain any combination of the following UFCs:

-4-Port UTP/STP

This UFC adds an additional four switched TRN ports to the module.

Interface: RJ45

Cabling: STP; UTP categories 3, 4, and 5

72 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

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-2-Port Fiber RI/RO UFC

This UFC enables switching between token-ring segments as far as 2 km away.

Interface: ST

Cabling: Multimode fiber

-1-Port ATM 155 Mbps Multimode Fiber UFC

This UFC provides an ATM interface that enables token-ring attached users to interoperate with ATM-attached devices that comply with the ATM Forum LAN Emulation specifications:

Interface: SC

Cabling: Multimode fiber

Supports token-ring/IEEE 802.5 emulated LAN types.

-1-Port RMON UFC

Support up to 1792 filter table entries per port, but no more than 10,000 filter table entries per module. These filter table entries can be either MAC addresses or source-route descriptor entries. These entries can be aged-out based upon configurable parameters at the port and module level.

Support a bandwidth aggregation feature, TokenPipe, which allows different LAN switching modules to be connected by up to four full-duplex connections, providing up to 128 Mbps of bandwidth between 8272 switching modules.

Support source route bridging that is fully compatible with existing source route bridges.

Support source route switching, in which frames are forwarded based on destination MAC addresses for locally attached stations and based on the routing information within the token-ring frame for non-locally attached stations (as is the case with source routing bridges to a maximum of seven bridge hops).

Note

If the module is configured for source route switching, all token-ring LAN ports and emulated token-ring LAN ports share the same ring number.

Gather statistics by:

-Port

-Connected station

-Switch

Support Plug-and-Play installation by automatically initializing as a multiport transparent bridge. This allows the module to learn the network addresses and eliminates all pre-installation configuration requirements. In most cases, however, you will eventually want to customize this initial configuration with such parameters as an IP address, SNMP parameters, and port filters.

Each port automatically identifies what kind of token-ring connection it has, determining whether it is:

Chapter 4. IBM 8285 ATM Modules 73

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-A lobe port to another concentrator

-A dedicated connection to a single device

-A connection to another token ring switch

-Operating at 4 or 16 Mbps

-Operating in halfor full-duplex mode

These automatic configuration capabilities can be disabled, for instance when connecting to an auto-speed-sensing adapter.

Support a transparent spanning tree configuration fully compliant with IEEE 802.1d standards. This ensures that there is only one path active to any segment in the network. The spanning tree function has configurable parameters for both port cost and port priority, enabling more accurate management of your network topology.

Support a maximum frame size of 4540 bytes. In cut-through mode, frames larger than 4540 bytes will be truncated and terminated with an abort sequence. In store-and-forward mode, the switch port will reject frames larger than 4540 bytes and will generate an error on the port.

Ethernet Features:

Support 12 10Base-T RJ-45 MDI-X ports using standard UTP category 3, 4, or 5 cabling or STP cabling.

Note

When using STP cabling, the patch cables at the switch port and at the workstation port should have an impedance-matching balun.

Have either two UFC slots (2-slot modules) or four UFC slots (3-slot modules), which can contain any combination of the following UFCs:

-4-port Ethernet 10Base-T UFC:

This UFC adds an additional four switched Ethernet ports to the module:

Interface: RJ45

Cabling: STP; UTP categories 3, 4, and 5

-3-port Ethernet 10Base-FL UFC:

This UFC enables switching between Ethernet segments that are physically distant (up to 2 kilometers away) from the module:

Interface: ST

Cabling: Multimode fiber

-1-port Ethernet 100BaseT UFC:

This UFC provides one 100BaseT Ethernet port for a connection to a 100BaseT backbone segment or directly to a LAN station or server equipped with a 100BaseT Ethernet adapter:

Interface: RJ45

Cabling: STP; UTP categories 3, 4, and 5

- 1-port Ethernet 100BaseFx UFC:

74 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

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This UFC provides one 100BaseFx Ethernet port for a connection to a 100BaseFx backbone segment or directly to a LAN station or server equipped with a 100BaseFx Ethernet adapter as far as 2 km away:

Interface: ST

Cabling: Multimode fiber

-1-Port ATM 155 Mbps Multimode Fiber UFC

This UFC provides an ATM interface that enables Ethernet-attached users to interoperate with ATM-attached devices that comply with the ATM Forum LAN Emulation specifications:

Interface: SC

Cabling: Multimode fiber

Supports Ethernet/IEEE 802.3 emulated LAN types.

Support up to 1790 active Ethernet addresses per port, but no more than 10,000 addresses per module. These addresses can be aged-out based upon configurable parameters at the port and module level.

Support a bandwidth aggregation feature, EtherPipe, which allows different LAN switching modules to be connected by up to four full-duplex connections, providing up to 80 Mbps of bandwidth between 8271 switching modules.

Gather statistics by:

-Port

-Connected station

-Switch

Support Plug-and-Play installation by automatically initializing as a multi-port transparent bridge. This allows the module to learn the network addresses and eliminates all pre-installation configuration requirements. In most cases, however, you will eventually want to customize this initial configuration with such parameters as an IP address, SNMP parameters, and port filters.

Table 8 and Table 9 provide comparisons of the token-ring modules and the

Ethernet modules, respectively.

Table 8. A Comparison of 8285 Token-Ring LAN Switch Modules

Module

 

 

 

Feature

 

 

Maximum Number of Ports

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Copper

 

Fiber

 

ATM 155

 

 

 

 

 

 

 

 

 

 

 

 

(RI/RO)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

-slot 8272 ATM/LAN Switch Module

 

 

5208

 

16

 

4

2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3

-slot 8272 ATM/LAN Switch Module

 

 

5308

 

24

 

8

4

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 9 (Page 1 of

2). A Comparison of 8285 Ethernet LAN Switch Modules

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Module

 

Feature

 

 

 

Maximum Number of Ports

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

10Base-T

 

10Base-F

 

100BaseT

100BaseF

 

ATM 155

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

-slot 8271 ATM/LAN

 

5212

20

 

6

 

 

2

 

2

 

2

Switch Module

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Chapter 4. IBM 8285 ATM Modules 75

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Table 9 (Page 2 of 2).

A Comparison of 8285 Ethernet LAN Switch Modules

 

 

 

 

 

 

 

 

 

 

Module

 

Feature

 

Maximum Number of Ports

 

 

 

 

 

 

 

 

 

 

 

 

10Base-T

10Base-F

100BaseT

100BaseF

ATM 155

 

 

 

 

 

 

 

 

3-slot 8271 ATM/LAN

 

5312

28

12

4

4

4

Switch Module

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4.9.1.1 ATM UFC I/O Feature

There are 2 ATM UFCs available, one ATM 1-port UFC for the Ethernet LAN switches and one ATM 1-port UFC for the token-ring LAN switches.

ATM 155 Mbps UFC: The ATM Multimode Fiber UFC achieves the ATM-to-LAN connection by providing an ATM Forum-compliant LAN emulation proxy client (LEC). It features the following:

Supports a single ATM 155 Mbps multimode fiber interface with SC connectors.

Supports SONET STS-3c framing.

Supports both UNI 3.0 and UNI 3.1 in accordance with ATM Forum specifications.

Supports switched virtual connections (SVCs) only and does not support permanent virtual connections (PVCs).

Supports best effort (Unspecified QoS), variable bit rate (VBR), and continuous bit rate (CBR) connections in accordance with ATM Adaptation Layer 5 (AAL-5) specifications.

Supports up to 3072 virtual channel connections (VCCs), requiring one VCC for each unique source/destination LEC pair.

Supports up to eight emulated LANs (ELANs), each represented by a logical emulated LAN port (ELP), all sharing the same physical link to the ATM network. However, it is not possible to have two ELPs assigned to the same ELAN on a single ATM UFC.

Does not support the VPI field of the virtual path/channel identifier.

Supports up to eight LECs which are compatible with LES/LECS Version 1.0 implementations. Each LEC can be pre-configured with the address of its required LAN Emulation Server (LES) or can discover the address of its LES dynamically via communication with a LAN Emulation Configuration Server (LECS).

Supports full media-speed throughput in both directions on its full-duplex ATM connection, assembling or disassembling an aggregate of approximately 177 Kbps (thousand 64-byte frames per second).

Supports the following management interfaces:

LEC MIB (ATM Forum LEC Management Specification Version 1.0)

AToM MIB (RFC 1695)

Interface group of MIB-II (RFC 1213 and 1573), enhanced to include ATM

The switch′s SNMP agent is accessible though any of the Ethernet or

token-ring LAN ports. When the LAN switch is configured with an ATM UFC, the switch′s SNMP agent is also accessible via an emulated LAN connection across an ATM port.

76 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

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Note

If the module is configured for source route switching, all token-ring LAN ports and emulated token-ring LAN ports share the same ring number.

4.9.2 Sample Scenarios

The 8285 LAN switching modules complement the IBM 8285 Base Unit′ s cost-effective ATM25 capabilities and can serve as the basis for a smooth migration from traditional shared-media LANs to the high-performance ATM

networks of the future. Here are some scenarios that could be implemented.

4.9.2.1 Stand-Alone Token-Ring Migration

In this scenario, a workgroup of 80 users and 4 servers has run out of bandwidth on its local token-ring network. A very simple way to alleviate this constraint is to implement an 8285 switch with a 3-slot 8272 ATM/LAN Switch Module right in the same wiring closet, as illustrated in Figure 30.

Figure 30. Relieving Token-Ring Congestion with LAN Switching Module

The first change to make is to move all four servers off of the common ring and give them dedicated bandwidth. If we use full-duplex token-ring adapters, such as the IBM Auto LANStreamer MC32 Adapter or the IBM Auto LANStreamer PCI Adapter, we can enable the servers for full-duplex operation, connect them to a LAN switch port, and let the LAN switch module automatically provide each server with 32 Mbps of dedicated bandwidth.

In addition, if we choose we can take advantage of the 8285 switch′s 155 Mbps ATM port by installing a high-performance ATM adapter, such as the IBM Turboways 155 Mbps adapter, in our most heavily used server.

Chapter 4. IBM 8285 ATM Modules 77

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Next, we can use microsegmentation to reduce the number of workstations that have to share the token-ring′s 16 Mbps of bandwidth. The segment size is limited only by the granularity of the token-ring concentrators you are using. If you are using a port-switching hub, such as the IBM 8260 Nways Multiprotocol Switching Hub, you can make your segments any size from two devices up to the architectural limit of the token-ring. And for those users who need the most performance that token-rings can provide, simply connect them directly to a port on the LAN switch module. This will provide them with up to 32 Mbps of dedicated bandwidth. In this case, since we have already used up 3 of our 24 available token-ring ports for the servers, we can have as many as 21 segments switched by the LAN Switching module.

Finally, to further reduce the number of workstations sharing token-ring bandwidth, you can begin to move some of your power users directly to the ATM network by installing ATM25 adapter cards, such as the IBM Turboways 25 adapter, in their workstations, running the simple migration utility, and connecting them to an ATM 25 Mbps port on the IBM 8285 Base Unit. They now have dedicated bandwidth of 25 Mbps to their desktop and access to all of the resources of the ATM network, while still retaining access to the shared media resources, such as the full-duplex token-ring servers. We do that with 12 of our workstations, reducing the number of workstations on shared token ring segments to 68.

Table 10 illustrates the before and after effects of our changes on the available bandwidth.

Table 10. Bandwidth Improvement with Token-Ring LAN Switch Module

Device

Maximum Bandwidth Available

Bandwidth

 

 

After...(Kbps)

 

Improvement

 

 

 

 

 

Ratio 2

 

Server

ATM

Micro-

ATM25

 

 

 

Offload

Server

segment

Offload

 

 

 

 

-ation 1

 

 

 

 

 

 

 

 

Primary Server

32000

155000

155000

155000

811x

 

 

 

 

 

 

Secondary Server

32000

32000

32000

32000

167x

 

 

 

 

 

 

Token-Ring

200

200

4000

4942 3

25x

Desktop

 

 

 

 

 

 

 

 

 

 

 

ATM Desktop

200

200

4000

25000

130x

 

 

 

 

 

 

Note:

1 In this case assuming an even distribution of four workstations per segment on each of 21 available token-ring segments.

2 Calculated by dividing the total bandwidth available after the change by the original bandwidth available per device, which was calculated by dividing the total bandwidth available by the number of devices sharing it. In this case, the original bandwidth calculation is: 16,000 Kbps/segment * 1 segment / (80 users + 4 servers) = 191 Kbps/device.

3. This is an average value. The 12 segments with three devices/segment would actually receive 5,333 Kbps while the remaining nine segments would have four devices apiece, each receiving 4,000 Kbps.

78 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

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Using a similar analysis, we can see in Table 11 on page 79, the bandwidth improvement possible for a constrained Ethernet environment of 40 users and 4 servers. In this scenario, we have added an 8285 switch with an 3-slot 8271 ATM/LAN Switch Module as shown in Figure 31 on page 79. In this case, however, rather than move our secondary servers to full-duplex Ethernet, we will go directly to 100base-Tx, providing each secondary server with 100 Mbps of dedicated bandwidth.

Figure 31. Relieving Ethernet Congestion with LAN Switching Module

Note

The choice of 100Base-Tx in this scenario is merely to demonstrate the versatility of the LAN Switch modules in conjunction with the 8285 switch. For the purposes of the example, we could have just as easily moved all of the servers to ATM directly, providing 155 Mbps to each server. Or we could have connected a shared 100Base-Tx segment to the LAN switch module to access resources on that segment and to provide ATM access to the 100Base-Tx users.

Table 11 illustrates the before and after results of our changes.

Table 11 (Page 1 of

2). Bandwidth Improvement with Ethernet LAN Switch Module

 

 

 

 

 

 

 

Device

 

Maximum Bandwidth Available (Kbps)

Bandwidth

 

 

 

 

 

 

Improvement

 

 

Server

ATM

Micro-

ATM25

 

 

Ratio 2

 

 

Offload

Server

segment

Offload

 

 

 

 

 

 

 

-ation 1

 

 

 

 

 

 

 

 

 

Primary Server

 

100000

155000

155000

155000

682x

 

 

 

 

 

 

 

Secondary Server

 

100000

100000

100000

100000

440x

 

 

 

 

 

 

 

Chapter 4. IBM 8285 ATM Modules 79

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Table 11 (Page 2 of

2). Bandwidth Improvement with Ethernet LAN Switch Module

 

 

 

 

 

 

 

Device

 

Maximum Bandwidth Available (Kbps)

Bandwidth

 

 

 

 

 

 

Improvement

 

 

Server

ATM

Micro-

ATM25

 

 

Ratio 2

 

 

Offload

Server

segment

Offload

 

 

 

 

 

 

 

-ation 1

 

 

 

 

 

 

 

 

 

Ethernet Desktop

 

250

250

4000

5714 3

25x

 

 

 

 

 

 

 

ATM Desktop

 

250

250

4000

25000

110x

 

 

 

 

 

 

 

Note:

1 In this case assuming an even distribution of three workstations per segment on each of 16 available Ethernet segments.

2 Calculated by dividing the total bandwidth available after the change by the original bandwidth available per device, which was calculated by dividing the total bandwidth available by the number of devices sharing it. In this case, the original bandwidth calculation is: 10,000 Kbps/segment * 1 segment / (40 users + 4 servers) = 227 Kbps/device. To be fair, this is a nominal value: in reality, the available bandwidth on a shared Ethernet segment rarely exceeds 40-50% of the rated bandwidth because of collisions and re-transmissions.

3 This is an average value. The four segments with one device would actually receive 10,000 Kbps/device, while the remaining 12 segments would have two devices a piece, each receiving 5,000 Kbps.

80 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

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Chapter 5. 8285 ATM Network Specifications

This chapter gives ATM connections and Traffic management specifications supported by the 8285.

5.1 ATM Connections

The IBM 8285 provides support for the following types of connections:

Permanent Virtual Connection (PVC) Two types of PVCs are supported:

PVC for virtual channel connections (VCC)

PVC for virtual path connection (VPC), also known as permanent virtual path (PVP)

Permanent Virtual Path (PVP)

Note that PVPs are not supported when they span over NNI links. However, PVPs are supported over SSI links.

Switched Virtual Connection (SVC)

Note: Switched virtual path (SVP) is not supported by the IBM 8285.

5.1.1 Supported VPI and VCI Range

The virtual path identifiers (VPIs) and virtual channel identifiers (VCIs) supported by the 8285 are depending the control point version.

Version 1.3:

For the 25 Mbps port:

VPIs are in the range 0-3.

VCIs are in the range of 32-1023.

For the other ports:

VPIs are in the range 0-15.

VCIs are in the range of 32-1023.

Note that certain workstation adapters have limited addressing capability as far as the supported VPIs and VCIs are concerned. These limitations are based on the number of bits in the ATM header that are recognizable by the workstation adapter and are defined in the ILMI packets exchanged by the adapter. The 8285 dynamically adjusts the supported VPI and VCI range on a port to the capability of the attached workstation at the ILMI exchange.

Version 1.4:

For the 25 Mbps ports:

One of the following three modes (ranges) can be selected:

VPI/VCI: 0 bit/12 bits (VPI=0, VCI=0 through 4095)

VPI/VCI: 2 bits/10 bits (VPI=0 through 3, VCI=0 through 1023)

VPI/VCI: 4 bits/8 bits (VPI=0 through 15, VCI=0 through 2556)

Copyright IBM Corp. 1996

81

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For the other ports:

One of the following three modes (ranges) can be selected:

VPI/VCI: 0 bit/14 bits (VPI=0, VCI=0 through 16383)

VPI/VCI: 4 bits/10 bits (VPI=0 through 15, VCI=0 through 1023)

VPI/VCI: 6 bits/8 bits (VPI=0 through 63, VCI=0 through 256)

For more details refer to 3.3.4, ªControl Point V1.4º on page 31.

5.1.2 Supported Virtual Connection Types

Table 12 shows the type of virtual connections supported by the IBM 8285.

Table 12. Supported Connection Type by the A-CPSW Module

Connection Type

Supported?

 

 

Unidirectional point-to-point

No

 

 

Bidirectional point-to-point with symmetric bandwidth

Yes

 

 

Bidirectional point-to-point with asymmetric bandwidth

No 1

 

 

Unidirectional point-to-multipoint

Yes

 

 

Bidirectional point-to-multipoint

No

 

 

multipoint-to-multipoint

No

 

 

1 If a call setup request with asymmetrical bandwidth requirement is received, the 8285 will establish the call with the higher peak rate used for both directions.

5.1.3 Maximum Number of Connections Supported

The maximum number of supported connections depends on their type

(point-to-point or point-to-multipoint) and for point-to-multipoint connections on the number of parties per connection. The following are the rules you can use to determine the number of connections supported in your environment:

The IBM 8285 has 4,096 connection control blocks.

Each point-to-point connection requires two control blocks.

Each party on a point-to-multipoint connection requires one connection control block.

The maximum number of point-to-point connections supported by an IBM 8285 with its expansion is 2,048 regardless the expansion unit installation.

The maximum number of point-to-multipoint trees supported is 127.

The maximum number of parties supported for all the point-to-multipoint trees is 1024.

The maximum number of PVCs is 100.

The maximum number of point-to-point connection per media modules or base unit is 2048 with Version 1.4 (was 992).

The maximum number of parties for point-to-multipoint connections for the base unit or per media module is 1024.

The maximum number of point-to-point connection per 8285 port is 2048.

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The maximum number of VPI connections supported per 25 Mbps port is 16 and 64 for the others.

5.1.4How PVCs Are Supported

To support PVCs, the 8285 maps them internally onto SVCs. This allows the PVC to be automatically reestablished using an alternate path in case of a link or node failure on the original path supporting the PVC. In addition, the parameters specified for the setting of the PVCs are saved in the NVRAM of the 8285 to provide automatic reestablishment of the PVC after the 8285 power off or reset condition.

Note that the information about PVCs is only stored in NVRAM after the connection is activated. This is to ensure that only the current and valid PVCs are restarted.

When an 8285 is restarted and an SVC is to be established before all the PVCs have been reestablished, a problem could occur if that SVC is allocated a label that is owned by one of the PVCs. To overcome this problem, the 8285 always checks to see if a label is not reserved by a PVC before allocating it to an SVC.

5.1.5 How to Configure PVCs

PVCs can be set up using the command line interface or the Nways Campus manager program. The following example shows how to configure a PVC for the configuration shown in Figure 32.

Figure 32. Sample PVC Configuration

Chapter 5. 8285 ATM Network Specifications 83

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8285A>set pvc 2.1 100 1.9 2 channel 0.500 0400 best_effort

 

 

 

 

 

 

Note that in this example, we have chosen the following attributes for the PVC:

Workstation attached on the local 8285: slot.port 2.1.

Workstation attached on the remote 8285: slot.port 1.9.

PVC_id = 100.

This is an arbitrary number that you can use to identify the PVC on various displays.

Remote hub identifier = 2.

This identifies the hub number (HN) of the remote hub (the hub on which the PVC terminates) within the cluster.

VPI/VCI on the local hub:

VPI = 1

VCI = 500

VPI/VCI on the remote hub:

VPI = 0

VCI = 400

PVC type = best_effort.

The VPI/VCI values chosen for each port must be free at the time of defining the PVC. You can find out the VPI/VCI values that are currently allocated to the other connections on the port by using the Nways Campus manager ATM for AIX. If you are not sure which VPI/VCI is available for allocation, you may use the following command, which will allow the 8285 Control-Point available VPI/VCI pair that is assigned for the PVC on each port:

 

 

 

 

 

8285A>set pvc 2.1 100 1.9 2 channel * * best_effort

 

 

 

 

 

 

You can display the configuration information about a specific PVC or all the PVCs using the SHOW PVC command. The following example shows the output that will be displayed as a result of this command:

 

 

 

 

 

 

 

8285A>

set pvc 2.1 100 1.9 2 channel 0.400 0.500 best_effort

 

 

 

 

 

 

PVC set and

started.

 

 

 

 

 

 

 

 

 

 

8285A>

show

pvc all

 

 

 

 

 

 

 

 

 

 

 

Local endpoint

| Remote endpoint

|

 

 

 

 

 

 

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

 

 

 

|-------------------

 

|

 

 

 

 

 

 

Port

id

type

Vpi/Vci

| Port Vpi/Vci

HNb|

role |QOS| Status

 

 

 

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

 

 

 

|-------------------

 

|

---------|---

|--------

 

 

 

2.01

100

PTP-PVC

0/500

|1.09

0/400

2| Primary | BE|Active

 

 

1.09

1001

PTP-PVC

0/400

|2.01

0/500

1|Secondary| BE|Active

 

 

 

8285A>

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

You may display additional information about the configuration of the PVC by using the verbose parameter in the SHOW PVC command as shown in the following example:

84 ATM Workgroup Solutions: Implementing the 8285 ATM Switch