IBM SG24-4817-00 User Manual

2.86 Mb
Loading...

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

viii ATM Workgroup Solutions: Implementing the 8285 ATM Switch

This soft copy for use by IBM employees only.

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

ix

This soft copy for use by IBM employees only.

x ATM Workgroup Solutions: Implementing the 8285 ATM Switch

This soft copy for use by IBM employees only.

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

Copyright IBM Corp. 1996

xi

This soft copy for use by IBM employees only.

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

This soft copy for use by IBM employees only.

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!

Preface xiii

This soft copy for use by IBM employees only.

xiv ATM Workgroup Solutions: Implementing the 8285 ATM Switch

This soft copy for use by IBM employees only.

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

Copyright IBM Corp. 1996

1

This soft copy for use by IBM employees only.

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:

2 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

This soft copy for use by IBM employees only.

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

This soft copy for use by IBM employees only.

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.

4 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

This soft copy for use by IBM employees only.

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

This soft copy for use by IBM employees only.

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:

6 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

This soft copy for use by IBM employees only.

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.

Chapter 1. Introduction to ATM Networks 7

This soft copy for use by IBM employees only.

8 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

This soft copy for use by IBM employees only.

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

9

This soft copy for use by IBM employees only.

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.

10 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

This soft copy for use by IBM employees only.

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

This soft copy for use by IBM employees only.

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.

12 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

This soft copy for use by IBM employees only.

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

Chapter 2. Introduction to the IBM 8285 Nways ATM Workgroup Switch 13

This soft copy for use by IBM employees only.

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

14 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

This soft copy for use by IBM employees only.

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.

Chapter 2. Introduction to the IBM 8285 Nways ATM Workgroup Switch 15

This soft copy for use by IBM employees only.

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.

16 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

This soft copy for use by IBM employees only.

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

This soft copy for use by IBM employees only.

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:

18 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

This soft copy for use by IBM employees only.

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)

Chapter 3. Functional Overview of the IBM 8285 19

This soft copy for use by IBM employees only.

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.

20 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

This soft copy for use by IBM employees only.

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.

Chapter 3. Functional Overview of the IBM 8285 21

This soft copy for use by IBM employees only.

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.

22 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

This soft copy for use by IBM employees only.

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.

Chapter 3. Functional Overview of the IBM 8285 23

This soft copy for use by IBM employees only.

 

 

 

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.

24 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

This soft copy for use by IBM employees only.

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

Chapter 3. Functional Overview of the IBM 8285 25

This soft copy for use by IBM employees only.

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

26 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

This soft copy for use by IBM employees only.

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

Chapter 3. Functional Overview of the IBM 8285 27

This soft copy for use by IBM employees only.

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

28 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

This soft copy for use by IBM employees only.

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.

Chapter 3. Functional Overview of the IBM 8285 29

This soft copy for use by IBM employees only.

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

This soft copy for use by IBM employees only.

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

Chapter 3. Functional Overview of the IBM 8285 31

This soft copy for use by IBM employees only.

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.

32 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

This soft copy for use by IBM employees only.

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

This soft copy for use by IBM employees only.

(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.

34 ATM Workgroup Solutions: Implementing the 8285 ATM Switch

+ 266 hidden pages