宽带网络技术基础（英文版）

Preface xxi

CBAPTER I Introduction 1

Introduction l

The Present Telecommunications Infraatructure l

Present Technologies for Voice, Video, and Data Networks 2

Present and Future Requirements 5

Downsizing and Outsourcing 6

Present Systems 6

Costs of Leased Lines 8

Virtual Companies and Virtual Networks 9

Fast Relay Networks and ATM 12

Development of ATM 14

Applications use of ATM 14

Fast Relay Networks and SONET 16

Broadband ISDN 19

Summary 2l

CHAPTER 2 The Nature ot Analog and Digital Systems 22

Introduction 22

Analog Systems 22

Cycles, Frequency, and Period 23

Bandwidth 24

Broadband and Baseband Signlals 26

Other Definitions of Broadband 27

Channel (Link) Capacity 27

Noiseless Channels and Harry Nyquest 28

Noisy Channels 29

The Signal-to-Noise Ratio 30

The Analog-to-Digital Conversion Process 30

Sampling, Quantizing, and Encoding 3l

Other Coding Schemes 34

Timing and Synchronization in Digital Networks 35

Plesiochronous Networks 35

The Synchronous Clock Hierarchy 36

Clarification of Terms 37

Timing Variations 37

Slips-Controlled and Uncontrolled 38

Bit or Clock Slips 39

Summary 39

CHAPTER 3 Layered Protocols, the Architeekure for ATM and SONET Networks 40

Introduction 40

Protocols and the OSI Model 40

OSI Layer Operations 42

Concept of a Service Provider 43

ATM and the Model 48

Protocol Entities 48

Service Accese Points (SAPs) 49

ATM and OSI Layers 49

The Internet Protocols (TCP/IP) 51

The Internet Layers 52

IP Functions 54

TCP Operations 56

The OSI Network and Transport Layer 58

Summary 58

CHAPTER 4 Emerged Technologies 59

Introduction 59

Comparison of Switching Systems 59

The TI/El Systems 61

Purpose of TI and E1 61

Typical Topology 62

T1 and E1 Layers 63

TI/E1 PDUs 63

Conclusions on T1/E1 65

X.25 65

Purpose of X.25 65

Typical Topology 66

X.25 Layers 67

X.25 PDUs 68

Other Noteworthy Aspects of X.25 69

Oonclusions on X.25 7O

Integrated Services Digital Network (ISON) 7l

Purpose of ISDN 71

Typical Topology 71

ISDN Layers 74

ISDN PDUs 74

Concluaions on ISDN 79

Signaling System Number 7 (SS7) 80

Purpose of SS7 80

Typical Topology 80

SS7 Layers 81

SS7 PDUs 84

Conclusions on SS7 85

ATM and SONET: Redoction (-r Enhancement of Functions in Networks 86

Summary 86

CHAPTER 5 The Broadband Integrated Services Digital Network (B-ISDN) Model 87

Introduction 87

ISDN and B-ISDN 87

B-ISDN Configurations 88

ATM and the B-ISDN Model 89

Examples of the Operations between Layers in the B-ISDN Planes 91

B-ISDN Functions 93

B-ISDN Service Aspects 95

Summary 97

CHAPTER 6 Asynchronous Transfer Mode (ATM) Basics 98

Introduction 98

The Purpose of ATM 98

Pertinent Standards 99

An ATM Topology 99

The VPI and VCI Labels l03

ATM Layers 105

ATM Layers and OSI Layers 106

Relationehip of AAL, ATM, and the Network 108

Relationship of Layers to the OSI Layered Architecture 11O

Where to Find Service Definitions and Primitives 111

Typical Protocol Stacks 111

ATM PDUs (CELLs) 113

Use of Two Identifiers 114

Metasignaling Cells and Other Cells 115

Rationale for the Cell Size 116

Network Traltsparency Operations 119

Emors and Error Rates 119

Emor Comection and Detection 122

Probability of Discarding Cells 124

Overhead of the Cell Approach 125

Transmission Delay 126

ATM Labele 128

Multiplexing VICs and VPIs 180

Cell Relay Bearer Service (CRBS) 190

Poink-to-Multipoint and Multipoint-to-Multipoint Services 132

ATM Interfaces 133

Principal Specificatiods for ATM 134

Summary 135

CHAPTER 7 The ATM Adaptation Layer (AAL) 137

Introduction 137

Principal Tasks of the AAL 137

The AAL Sublayers 139

Creating and Processing the AAL PDU 139

Classes of Traffic 141

Rationale for AAL Types 143

Dividing CS into Further Sublayers 143

AAL Naming Conventions 144

AAL Type 1 (AAL 1) 144

The AAL l PDU 145

AAL l Modes of Operation 147

Synchronization and Clock Eecovery 148

Running AAL 1 Traffic on a T1 Link 148

AAL Type 2 (AAL 2) 149

The AAL 2 PDU 150

Voice Packetization 152

Grouping Samples into Blocks 153

The Voice Packet 156

Packet Buildout at the Receiver 158

AAL Types 3, 4, 3/4, and 5 (AAL 3, AAL 4, AAL 3/4, and AAL 5) for Data 161

Pre-ATM Approach to Traffic Integrity Management 161

ATM Approach to Traffice Integrity Management 164

The Original AAL Type 3 and Type 4 (AAL 3, AAL 4) 166

AAL 3/4 167

Naming Conventions for AAL 3/4 167

The AAL 3/4 PDU 167

AAL 8/4 Headers and Trailers 167

AAL 3/4 Sequencing and Identification Operations l70

A Complete SAR-PDU and CPOS-PDU Examole 17l

Functional Model for AAL 3/4 173

AAL Type 5 (AAL 5) 175

Structure of AAL 5 176

The AAL 5 PDU 176

A New Type-Available Bit Rate (ABR) l77

The AAL/ATM Printitives 177

Summary 180

CHAPTER 8 ATM Switching Operations l8l

Introduction 18l

ATM Switching 181

Routine with the Cell Header 182

Snace and Time Switching 185

Digital Cross Connects 186

The Switching Fabric 186

Multiplexing and Label Mapping 189

Switching Technologies 19l

Shared Memory Switch 192

Shared Bus Switch 192

Crossbar Switch 193

Multistage Switching 194

Banyan and Delta Switching Networks l95

Example of an ATM Switch 200

Summary 202

CHAPTER 9 Traffic Management 203

Introduction 203

Traffic Managemnet in an ATM Network 203

The Natural Bit Rate 204

Traffic Control and Congestion Control 206

Functions to Achieve Traffic Control and Congestion Control 206

Allocation of Bandwidth 206

Computing the Parameters for Queue Servicing 2l0

Dealing with Variable Delay 21l

Connection Admission Control (CAC) Procedures 212

Usage Parameter Control (UPC) 214

Performance Parameters at the UNI 215

ITU-T Recommendation I.35B 215

Traffic Management at the UNI-Basic Concepts 215

Eckberg Scheme 215

Multiplexing Traffic into the Cells 218

Token Pools and Leaky Buckets 218

Allocating Resources 222

ATM Bearer Service Attributes at the UNI 222

Trafiic Control and Congestion Control 223

Cell Arrival Rate and Cell Interval 224

ATM Cell Transfer Performance Parameters 226

ATM Layer Provisions for Quality of Service (QOS) 227

ATM Forum and ITU-T Traffic Control and Congestion Control 228

Generic Cell Rate Algorithm (GCRA) 229

The Peak Cell Rate Reference Model 230

Cell Delay Variation (CDV) Tolerance 233

Managing LAN Traffic with the Available Bit Rate (ABR) 235

Examples of ABR Operations 235

Types of Feedback 238

Buildout Delay Procedures at the Receiving Endpoint 240

Summary 240

CHAPTER 10 Call and Connection Control 241

Introduction 24l

ATM Connections on Demand 241

The ATM Address 244

Addlress Registration 247

The Connection Control Messages 248

Conneetion Setups and Clears 248

Q,293l Timers and States 250

Connection Control Examples 251

Connection Setup 252

Connection Release 254

Restart Procedure 255

Status Inquity 256

Add Party 256

Drop Party 259

Signaling AAL Reset and Failure 259

Functions of Q.2931 Messages and Information Elements 260

Messages for Call Control 260

Messages for Restart Operations 260

Messages for Adding and Dropping

Parties 260

Descriptions of the Information

Elements 262

Examples of Q.293l Messages 269

Coding Conventions 269

AAL Parameters 270

User Traffic Descriptors 274

Summary 275

CHAPTER 11 Inkernetvvorking with ATM NetWorks 276

Introduction 276

The ATM Network as the Backbone for Other Networks 276

Using Q.293l to Support Protocol Capability (Tunneling) 277

Broadband Low-Layer Infomlation Element 280

The Network-to-Network Interface 283

The ATM B-ISDN Inter Carrier Interface (B-ICI) 284

Physical Layer Requirements at the B-ICI 287

Trafffic Management at the B-ICI 287

Reference Traffic Loads 287

B-ICI Layer Management Operations 288

Specific Intemetworking Services 289

PVC Cell Relay Service (CRS) 289

PVC Circuit Emulation Service (CES) 290

PVC Frame Relay Service (FRS) 290

SMDS Service 295

ATM Backbones for LANs 297

ATM LAN Emulation 299

ATM Edge Routers 301

ATM Virtual Routers 30l

RFC 1483 and RFC 1577 302

The ATM Data Exchange Interface (DXI) 303

DXI Modes 303

DXI Support for Frame Relay 308

Summaty 3lO

CHAPTER 12 Synchronous Optical Network(SONET) 311

Introduction 31l

Purpose of SONET 3ll

Present Transport Systems and SONET 313

Foundations for SONET 313

Synchronous Networks 315

Optical Fiber-The Bedrock for SONET 316

Pertinent Standards 317

Typical SONET Topology 319

SONET Configuration 32l

SONET Layers 323

Automatic Protection Switching (APS) 324

Payloads and Envelopes 326

Envelopes 326

Mapping ATM Cells into the SONET Envelope 329

Payload Pointers 330

Mapping and Multiplexing Operations 33l

The Control Headers and Fields 334

SONET Equipment 335

Progress in SONET Penetration 342

Summary 342

CHAPTER 13 Signaling:Operations,Administration,and Maintenance (OAM) 343

The Network Management Model 343

Operation and Maintenance (OAM) Operations 344

ATM Functions at the U-and M-Planes 347

U-Plane Operations 347

M-Plane Operations 349

End-to-End and Segment Flows 350

The SONET OAM Functions 353

Maintenance and Alarm Surveillance 353

Failure States 353

Alarm Indication Signals (AIS), FERF and Yellow Signals 354

Examples of Remedial Actions upon Entering a Failure State 355

The OAM Headers 356

Section Overhead 357

Line Overhead 358

STS Path Overhead (STS POH) 358

ATM Use of the OAM Octets 360

Using Payload Pointers for Troubleshooting Timing Problems 36l

OAM at the ATM Layer 362

Fault Management 362

Performance Management 364

Activation/Deactivation 367

The ATM Managemer.t Information Bases (MIBs) 368

The Interim Local Management Interface (ILMI) 369

The ILMI MIB Groups 370

ATM MIB (RFC 1695) 372

The ATM MIB Groups 372

The ILMI MIB and the ATM MIB 377

The Layer Management/ATM Primitives 379

Types of Sigllaling 379

Status of Common Channel Signaling Standards 379

Summary 380

CHAPTER 14 Physical Layer Services for ATM 381

Introduction 381

Physical Layer Options for ATM 381

The ATM/Physical Layer Primitives 382

ATM Mapping into SONET STS-3c 383

ATM Mapping into DS3 385

Other Aspects of the DS3 Scheme 387

ATM Mapping into the IOO Mbit/s Multimode Fiber Interface 387

Functions of the U-Plane Physical Layer 387

ATM Mapping into the 155.52 Mbit/s Private UNI 390

Multimode Fiber Interface 390

Shielded Twisted Pair Interface 390

Private UNI for 51.84 Mbit/s and Subrates 390

Mapping DS1, DS3, and CEPT Payloads into SONET Frames 392

The VT/VC Structure 393

Floating and Locked VT Mode 396

Interworking ATM and SONET 397

Summary 398

CHAPTER 15 The ATM Market 400

Introduction 400

Forecasts on the Use of ATM 400

ATM Over T1/E1 402

Trials and Test Beds 403

ATM Vendors 405

DEC and IBM ATM Efforts 409

ATM Progress in Europe 410

United Kingdom 41O

Examples of other Countries' ATM Efforts 412

Some Final Thoughts 412

References 414

Abbreviations 4l8

Index 42O