数据网络设计 第2版PDF电子书下载

Part 1 Data Communications——Business Drivers and Networking Directions 1

Chapter 1.Data Communications——Past to Future 3

1.1 What is Network Design? 3

1.2 Deflning Data Communications Needs 8

1.3 From Voice Networks to Data Networks 9

1.3.1 A Brief History of Communications 9

1.3.2 A Recent History of Data Communications 12

1.4 Current Network Infrastructure——The Telephone Network 13

1.4.1 The United States 14

1.4.2 Europe and the Pacific Rim 16

1.4.3 Voice as Low-Speed Data 16

1.4.4 Voice and Data over the Current Network Infrastructure 17

1.5 The Data Revolution 18

1.5.1 Data Communications Takes the Lead 19

1.5.2 Business Relies on Data Communications 21

1.5.3 A New World Order for Data? 22

1.6 The New World Data Manager or Engineer——Think Data Services 23

1.6.1 The Data Services Option 24

1.6.2 Not Just Faster and Larger,but Smarter Networks 25

1.6.3 Planning 25

1.6.4 Psychology 26

1.6.5 The Data Manager and the Data Engineer 27

1.7 Outsourcing and Out-tasking Ttends Continue 28

1.7.1 Outsourcing and Out-tasking Defined 29

1.7.2 Outsourcing Considerations 30

1.7.3 Resources 31

1.7.4 Skill Sets and Rellability 32

1.7.5 Monetary Impacts and Retum on Investment(ROI) 32

1.7.8 How Long? 34

1.7.7 To What Extent? 34

1.7.6 Control 34

1.7.9 Vendor/User Reiationships——The Contract 35

1.7.10 Cost of Ownership——Make vs.Buy Analysis for Management 35

1.7.11 Summary of Benefits and Drawbacks 37

1.7.12 The Future of Outsourcing 38

1.8 Review 38

Chapter 2.Computer and Information Nertworking Directions 41

2.1 Applications as Key Enabiers 41

2.1.1 Consumer and Commercial Applications 42

2.1.2 Application Demand for Bandwidth 43

2.1.3 New Multimedla Applications 44

2.1.4 The Accelerating Bandwidth Principle 46

2.1.5 Power to the Desktop 49

2.2.1 S Curves of Technological Evolution 51

2.2 Communications Technologies as Enablers 51

2.2.2 Technology Acceptance Phases 52

2.2.3 Protocol Enhancements 54

2.2.4 High-Performance Digital Transmission 54

2.2.5 ATM as a Technology Enabier 54

2.2.6 Technology That Future-Proofs Your Investment 56

2.3 Corporate Infrastructures are Changing 57

2.3.1 Transmission Infrastructure Evolution 57

2.3.2 From Centralized to Distributed Networks 58

2.3.3 Distributed Computing and Cllent-Server Networking 60

2.3.4 IBM SNA and Internetwork Protocol Convergence 61

2.3.5 The Need for LAN/MAN/WAN Connectivity 61

2.3.6 The Death of Shared Modia——LAN Switching? 63

2.3.7 The Move to Distributed Routing 64

2.3.9 Virtual LAN(VLAN) 65

2.3.8 Merging of LAN and WAN——Free Bandwidth? 65

2.3.11 Seamiess Protocol and Service Interworking——ATM? 66

2.3.10 Intranet within the Internet and Cllent-Server Intranetworks 66

2.4 The Data Network of the 2000s 68

2.4.1 Private and Virtual Private Networks(VPNs) 68

2.4.2 The Intelligent Data Network 73

2.4.3 Meeting the Needs of the Enterprise 74

2.4.4 Virtual Network Partitioning and Security 75

2.4.5 The War on Technological Obsol??cence 77

2.4.6 Ublquitous Access and Any-to-Any Communlcations 78

2.4.7 As Rellable as the Phone Network 78

2.4.8 Interoperability 79

2.5 Review 79

Part 2 Standards and Services 81

3.1 Creating Standards——The Players 83

Chapter 3.Understanding the Standards and Their Makers 83

3.1.1 Vendors 84

3.1.2 Users 84

3.1.3 Network Service Providers 85

3.2 Creating Standards——The Process 85

3.2.1 Work Plan 86

3.2.2 Maetings and Contributions 86

3.2.3 Drafting and Review 87

3.2.4 Voting and Approval 87

3.2.5 User Acceptance and Interoperability 88

3.2.6 Business and Politics 88

3.3 Standards and Specification Bodies 89

3.3.1 International Telecommunications Union(ITU) 90

3.3.2 American National Standards Institute(ANSI) 91

3.3.3 ANSI T1 Standards Committee 92

3.3.4 Alliance for Telecommunications Industry Solutions(ATIS) 93

3.3.5 European Telecommunlcations Standards Institute(ETSI) 94

3.3.6 Institute for Electrical and Electronics Engineers(IEEE) 94

3.3.7 Bell Communications Research(Bellcore) 95

3.3.8 International Organization for Standardization/International Electrotechnical Commission(ISO/IEC) 96

3.3.9 Federal Communications Commission(FCC) 97

3.3.10 Additional National Standards Bodies 97

3.3.11 Additional International Standards Bodies 98

3.3.12 How Do They Interface? 99

3.4 Current Forums 100

3.4.1 Frame Relay Forum 102

3.4.2 SMDS Interest Group(SIG) 102

3.4.3 ATM Forum 102

3.4.4 Internet Engineering Task Force(IETF) 103

3.4.5 Additional National Forums 104

3.5 Review 105

Chapter 4.Protocol and Transmission Basics 107

4.1 Basic Protocol-Layering Concepts 108

4.2 Layered Reference Models——The OSIRM 110

4.3 Layers of the OSI Reference Model 112

4.3.1 Physical Layer 112

4.3.2 Data Link Layer 113

4.3.3 Network Layer 114

4.3.4 Transport Layer 114

4.3.5 Session Layer 115

4.3.6 Presentation Layer 115

4.3.7 Application Layer 116

4.4 Standard Computer Architectures 116

4.4.1 IEEE 802.X Series(LAN/MAN/WAN) 116

4.4.2 The Integrated Services Digital Natwork(ISDN)Protocol Model 118

4.4.3 IBM s Systems Network Architecture(SNA) 120

4.4.4 Digital Equipment Corporation s Digital Network Architecture(DNA)and DECnet Phases IV and V 122

4.4.5 General Motors Manufacturing Automation Protocol(MAP) 124

4.4.6 Boeing Computer Services Technical and Office Protocol(TOP) 124

4.4.7 Novell s Internet Package Exchange(IPX) 126

4.4.8 AppleTalk 127

4.4.9 Xerox Network Systems(XNS) 128

4.4.10 Architecture Joint Ventures 128

4.4.11 Architecture Comparison to the OSIRM 130

4.5 Digital Time Division Multiplexing(TDM)and the Digital Hierarchy 131

4.5.1 Plesiochronous Digital Hierarchy 131

4.5.2 SONET and the Synchronous Digital Hierarchy(SDH) 132

4.6 Basics and History of ISDN 133

4.6.2 BRI and PRI Service and Protocol Structures 134

4.6.1 ISDN Basics 134

4.7 Definition of Network Services 137

4.7.1 Connection-Oriented Network Services(CONS) 137

4.7.2 Connectionless Network Services(CLNS) 139

4.8 Review 140

4.9 References 141

Part 3 The Basics——Transmission,Networks,Hardware,and Switching 143

Chapter 5.Transmissions,Networks,and Hardware Types 145

5.1 General Network Topologies 145

5.1.1 Point-to-Point 146

5.1.2 Common Bus(Multipoint) 147

5.1.3 Star 148

5.1.4 Ring 149

5.1.5 Mesh 150

5.2.1 Connection Types:Simplex,Half-Duplex,and Duplex 152

5.2 Connection and Circuit Types and Services 152

5.2.2 Multidrop Circuits 153

5.2.3 Private Lines and Local Loops 155

5.2.4 ADSL and HDSL 155

5.3 Private Leased Lines vs.Switched Networks 156

5.3.1 Private(Leased)Line Networks 157

5.3.2 Switched Networks 159

5.3.3 Hybrid Networks 160

5.4 Data Tranamission Methods 160

5.4.1 Asynchronous and Synchronous Data Transmission 160

5.4.2 Asynchronous versus Synchronous Transfer Mode 162

5.5 Hardware Distinctions 163

5.5.1 Repeaters 164

5.5.3 Channel Service Unit(CSU)and Data Service Unit(DSU) 165

5.5.2 Line Drivers/Limited-Distance Modems 165

5.5.4 Intelligent LAN Hubs 167

5.5.5 Bridges 170

5.5.6 Routers 175

5.5.7 Routing Compared to Bridging 178

5.5.8 Brouters 180

5.5.9 Switches 180

5.5.10 Gateways 183

5.5.11 From Bridges to Routers to Hubs 183

5.5.12 The PBX 184

5.6 Review 185

Chapter 6.Multiplexing and Switching Technologies——An Overview 187

6.1 Multiplexing Technologies 187

6.1.1 Multiplexer Defined 188

6.1.2 Multiplexing Methods Summnarized 189

6.1.3 Space Division Multiplexing(SDM) 189

6.1.4 Frequency Division Multiplexing(FDM) 190

6.1.5 Time Division Multiplexing(TDM) 192

6.1.6 Address or Label Multiplexing 195

6.2 Types of Multiplexers 196

6.2.1 Access or Channel Bank Multiplexers 197

6.2.2 Network Multiplexers 199

6.2.3 Aggregator Multiplexers 200

6.2.4 Drop-and-Insert Multiplexers 201

6.2.5 Selection of a Multiplexer 202

6.2.6 The Future of Multiplexing 203

6.3 Switching Techniques 204

6.3.1 Point-to-Point Switching Functions 204

6.3.2 Point-to-Multipoint Switching Functions 205

6.3.3 Space Division Switching 206

6.3.4 Time Division Switching 207

6.3.5 Address Switching 208

6.3.6 Frequency/Wavelength Switching 210

6.3.7 The Matrix Switch 212

6.4 Circuit Switching Methods 212

6.4.1 Circuit Switching Illustrated 213

6.4.2 Switched n x 56 kbps and n x DSO 214

6.4.3 Digital Access Cross-Connects(DXC) 217

6.4.4 Dial-Up Lines 219

6.5 Packet-Switching Technologies 219

6.5.1 X.25 Packet Switching Compared to Circuit Switching 220

6.5.2 Darwin s Theory and Packet Switching Evolution 220

6.5.3 X.25 222

6.5.4 Frame Relay 222

6.5.5 Fast Packet 223

6.5.6 Asynchronous Transfer Mode(ATM) 224

6.6 Review 225

6.5.7 Integrated Circuit/Packet Switches 225

Part 4 Protocols and Interfaces 227

Chapter 7.Common Protocols and Interfaces——Part 1 229

7.1 Basic Concepts 229

7.1.1 Physical Layer Concepts 230

7.1.2 Data Link Layer Concepts 231

7.1.3 Network and Transport Layer Concepts 232

7.2 Physical Layer Protocols and Interfaces 232

7.2.1 Physical Media 232

7.2.2 RS-232-C,EIA-232-E,EIA-449,and ITU-T V.24/V.28 233

7.2.3 ITU-T X.21,X.2I 234

7.2.4 ITU-T I.430 and I.431 234

7.2.5 T1/E1 and D4/ESF Framing and Formatting 238

7.2.6 AMI and B8ZS Line Coding 239

7.2.9 Enterprise Systems Connection ArchitectureTM(ESCON) 240

7.2.7 High-Speed Serial Interface(HSSI) 240

7.2.8 High-Performance Parallel Interface(HIPPI) 240

7.2.10 Flbre Channel 242

7.2.11 IEEE 802 Physical Interfaces 242

7.3 Data Link Layer Protocols 244

7.3.1 Binary Synchronous Control(BSC or Bisync) 245

7.3.2 Digital Data Communications Message Protocol(DDCMP) 246

7.3.3 Synchronous Data Link Control(SDLC) 246

7.3.4 High-Lavel Data Link Control(HDLC) 248

7.3.5 Link Access Procedure(LAP)Protocols 252

7.3.6 Point-to-Point Protocol(PPP)and Serial Line Interface Protocol(SLIP) 252

7.4 LLC and MAC Sublayer Protocols 253

7.4.1 Logical Link Control(LIC)Sublayer 255

7.4.2 Medis Access Controi(MAC)Sublayer 257

7.4.3 802.3 CSMA/CD(Ethernet) 259

7.4.4 802.4 Token Bus 261

7.4.5 802.5 Token Ring 262

7.4.6 Fiber Distrlbuted Dats Interface(FDDI) 263

7.4.7 FDDI-II 269

7.4.8 100-mbps Ethernet:100BASET and 100VG-AnyLAN 270

7.5 Switching in the LAN Environment 271

7.5.1 Ethernet and Token Ring LAN Switch 273

7.5.2 When Should You Use a LAN Switch? 273

7.5.3 Types of LAN Switching 274

7.5.4 Virtual LANs and LAN Emulation 276

7.6 Review 278

Chapter 8.Common Protocois and Interfaces——Part 2 279

8.1 Bridge Protocols 279

8.1.2 IBM Source Routing Protocol(SRP) 280

8.1.1 IEEE 802.1 Spanning Tree Learning Bridge Protocol(STP) 280

8.1.3 Source Route Transparent(SRT)Bridging 282

8.1.4 Source Routing Extensions 282

8.2 Router Protocols 282

8.2.1 Routing Protocols Defined 283

8.2.2 Distance Vector Routing Protocols 284

8.2.3 Link State Routing Protocols 286

8.2.4 Routing Protocols Comparison 287

8.3 Network and Transport Layer Protocols——The Internet Protocol Suite(TCP/IP) 288

8.3.1 Origins of TCP/IP 288

8.3.2 Structure of TCP/IP 288

8.3.3 IP Packet Formats 290

8.3.4 Internet Protocol(IP)Addressing 291

8.3.5 TCP Frame Format 292

8.3.6 TCP/IP Functions 292

8.3.8 Traffic and Congestion Control Aspects of TCP/IP 293

8.3.7 Example of TCP/IP Operation 293

8.3.9 Service Aspects of TCP/IP 295

8.3.10 IP Next Generation(IPng)-IPv6 295

8.4 Legacy SNA 297

8.4.1 Building Blocks of Traditional SNA 298

8.4.2 Network Addressable Units——PUs,LUs,and Domains 302

8.4.3 SNA Legacy Software Communications 303

8.5 IBM SMA/SDLC Migration to LAN/WAN Internetworking 304

8.5.1 SNA over X.25——NPSI 306

8.5.2 QLLC Conversion——SNA over X.25 306

8.5.3 PAD/FRAD SDLC/Bisync/Async Consolidation/Encapsuiation 306

8.5.4 Traditional Source Route Bridging(SRB)and Remote SRB(RSRB) 307

8.5.5 SDLC to LLC2 Protocol Conversion 308

8.5.6 SNA SPLC Serial Tunneling(Synchronous Pass-Through)over IP 309

8.5.7 RFC 1434,DLSw(RFC 1795),DLSw+,and RSRB 312

8.5.8 RFC 1490——SNA and Multiprotocol Traffic Encapsulation across FR Networks 314

8.6 APPC/APPN 316

8.6.1 APPC 316

8.6.2 APPN 317

8.6.3 High Performance Routing(HPR)and Dependent LU Requester(DLUR) 318

8.6.4 Channel Extension——Cisco s Channel Interface Processor(?) 319

8.6.5 NETBIOS/NETBEUI 320

8.6.6 SNA-to-OSI Gateway 320

8.7 Review 320

Chapter 9.X.25 Packet Switching 321

9.1 A Brief History of Packet Switching 321

9.1.1 Packet Switch Beginnings 322

9.1.2 Early Reasons for Packet Switching 323

9.1.3 Principies of Packet Switching 323

9.1.4 X.25 Packet Switching Today 325

9.2.1 Orlgins of X.25 326

9.2.2 Standards Structure of X.25 326

9.2 X.25 Packet Switching Defined 326

9.2.3 What Does X.25 Packet Switching Provide? 327

9.2.4 Packet-Switch DTE and DCE Concepts 328

9.3 Theory of Operation 330

9.3.1 Traffic Characteristics 330

9.3.2 Basic Operation 332

9.3.3 Acknowledgments 333

9.3.4 Packet Sequencing 334

9.3.5 Example of X.25 Store-and-Forward Operation 334

9.3.6 Packet Error 335

9.3.7 Lost Packets 336

9.3.8 Packet Duplication 336

9.4.2 X.25 and the OSI Reference Model 337

9.4 X.25 Interface Protocol Structures 337

9.4.1 CCITT Recommendation X.25 337

9.4.3 Data Link Frame Structure 339

9.4.4 The Packet Layer DTE/DCE Interface 339

9.4.5 X.25 Layer 3 Packet Format 341

9.5 Network Layer Functions 342

9.5.1 Permanent Virtual Circuits and Virtual Calls 343

9.5.2 Virtual Calls and Logical Channel Numbers 344

9.5.3 X.25 Control Packet Formats 347

9.5.4 Normal Data Packet Formats 348

9.5.5 Flow Control and Windowing 348

9.5.6 Datagram Function 350

9.6 User Connectivity 351

9.6.1 User Network Interface 351

9.6.2 User Applications 353

9.6.3 User-to-User Protocols 354

9.6.4 Optional User Facillties(Section 6.0 of the Standards) 354

9.6.5 Fast Connect Option 354

9.7 Performance and Design Considerations 356

9.8 X.75 Internetworking Protocol 357

9.9 Advantages and Drawbacks 358

9.10 Review 359

Chapter 10.Frame Relay,Part 1——Teory 361

10.1 Origins and Standards of Frame Relay 362

10.2 Frame Relay Defined 363

10.2.1 FR User-Access Ports and Circuits(FR UNIs) 363

10.2.2 Permanent Virtual Circuit(PVC) 365

10.2.3 Committed Information Rate(CIR) 367

10.2.4 Data Link Connection Identifier(DLCI) 367

10.2.5 Frame Relay Functions——Putting It All Together 368

10.3 The Many Faces of Frame Relay——Interface,Signaling Protocol,and Service 369

10.3.1 Frame Relay Access to a FR Network 370

10.3.2 Frame Relay as a Signaling Protocol 376

10.3.3 Frame Relay as a Network Service 378

10.4 Transmission and Signaling Protocol Structure 384

10.4.1 Frame Relay Protocol Structure in Relation to the OSIRM 384

10.4.2 Layer 2 Protocol Structure Details 387

10.4.3 Core Services 389

10.4.4 Procedural Sublayer Services 390

10.5 Transmission Protocol Theory 391

10.5.1 Overview 392

10.5.2 Example of Frame-Relay Operation 395

10.5.3 Basics of SAP and DLCL 396

10.5.4 Frame Format 398

10.5.5 Address Field Structure 399

10.5.6 Proposed Address Structures of ANSI T1.618 401

10.5.7 Data Field or Payload Structure 403

10.5.8 Frame Check Sequence(FCS) 404

10.6 Frame Relay Addressing 404

10.6.1 FR Addressing with DLCIs 404

10.6.2 Frame Handling and Switching with ISDN FR Access 405

10.6.3 Logical Channel Multiplexing vla Frames 406

10.7 User-Definable Services 409

10.7.1 User Interface 409

10.7.2 User Applications 409

10.7.3 Interface Signaling 410

10.7.4 PVC Management 410

10.7.5 The Local Management Interface(LMI)Extension 411

10.8 Review 413

Chapter 11.Frame Relay,Part 2——Application,Services,and Design 415

11.1 Multiple Standards Deveiop 416

11.1.1 ITU-T/CCITT Standards 417

11.1.2 ANSI Standards 418

11.1.3 LMI Extension and Proprietary Solutions 419

11.1.4 Standard LMI Extensions 420

11.1.5 Optional LMI Extensions 421

11.2 FR Parameters and Sizing 422

11.2.1 Calculating the Committed Information Rate(CIR)and Excess Information Rate(EIR) 422

11.2.2 CIR Sizing 423

11.2.3 FR Access Port Sizing 425

11.2.4 Unldirectional,Asymmetrical,or Simplex PVCs 426

11.2.5 Bursting over CIR 427

11.2.6 Discard Eligible(DE) 429

11.2.7 Oversubscription 429

11.2.9 Moving from PL to FR 430

11.2.8 PVC Reroute Capability 430

11.3 Traffic and Congestion Control Aspects of Frame Relay(CIR,EIR,FECN,BECN,CLLM):Design Issues 431

11.3.1 Congestion in Frame Relay Networks Defined 431

11.3.2 FECN and BECN 432

11.3.3 Consolidated Link Layer Management(CLLM) 434

11.4 Public Network FR Services 434

11.4.1 Service Aspects of Frame Relay 436

11.4.2 Public versus Private 437

11.4.3 Public Frame Relay Service Offerings 438

11.4.4 Switched Virtual Circuits(SVCs) 440

11.4.5 Network-to-Network Interface(NNI) 441

11.4.6 Frame-Relay Service Provider Interconnectivity Issues 442

11.4.7 Regional,National,or International? 442

11.4.8 International Frame Relay 444

11.5 Public Frame Relay Network Architectures 444

11.5.1 Open-Loop Architecture 445

11.5.2 Closed-Loop Architecture 447

11.5.3 FR over a Cell-Relay Backbone 448

11.5.4 Input/Output Buffers 448

11.6 Access Design Issues 449

11.6.1 Network Access Devices 449

11.6.2 Frame Relay Access Device(FRAD) 450

11.6.3 Dial Access and Dial Backup 453

11.6.4 Network Management 456

11.7 Performance Design Issues 456

11.7.1 Transmission Error Rates and Lost Frames 457

11.7.2 Propagation Delay 457

11.7.3 Transamission Transit Delay 457

11.7.4 Queuing,Seriaiization,and Packetization Delay 458

11.7.6 Window Sizing and Effects on Higher-Layer Protocois 459

11.7.5 Overhead and Throughput 459

11.7.7 Buffering and Throughput during Congestion 460

11.7.8 Bursting and Jitter Eflects on Applications 460

11.7.9 Traffic Prioritization 461

11.8 Pricing,Rates and Tariffs 461

11.8.1 Elements of FR Pricing 461

11.8.2 Tariff or Nontariff? 462

11.8.3 Usage-Based Pricing an Option? 462

11.8.4 Comparison Pricing Guidelines 463

11.8.5 Zero CIR 464

11.8.6 Build versus Buy 465

11.9 Review 465

Chapter 12.SMDS 467

12.1 Switched Multimegabit Data Service(SMDS)Defined 467

12.1.1 Origins of SMDS 468

12.1.2 What is a MAN? 470

12.1.3 SMDS Service——Public versus Private 472

12.2 Subscriber Interfaca and Access Protocols 472

12.2.1 SMDS L3_PDU 472

12.2.2 SMDS Subscriber Network Interface(SNI) 474

12.2.3 SMDS Interface Protocol(SIP) 474

12.2.4 Data eXchange Interface(DXI) 475

12.2.5 Frame Relay Access 477

12.2.6 SMDS to ATM Access 478

12.2.7 The Customer Premises Environment(CPE) 478

12.3 Addressing and Traffic Control 479

12.3.1 Unicasting and Multicasting(Group Addressing) 480

12.3.2 Source Address Validation and Address Scceening 480

12.3.4 Access Classes 481

12.3.3 SIR Access Classes as Traffic and Congestion Control 481

12.3.5 SMDS Addressing 483

12.4 SMDS and DQDB Protocol Structures 484

12.4.1 IEEE 802.6 Compared to the OSIRM 484

12.4.2 Structure of SMDS and IEEE 802.6 484

12.4.3 SMDS/802.6 Protocol Data Unit (PDU)Formats 486

12.5 SMDS and DQDB Architecture 488

12.5.1 SMDS Backbone Architecture 489

12.5.2 DQDB and SMDS Functions 490

12.5.3 DQDB Architecture——Bus Defined 493

12.5.4 Example of SMDS over DQDB Operntion 494

12.5.5 Overhead and Throughput Degradation 494

12.6 SMDS Internetworking——Bridging and Routing 496

12.6.2 SMDS Routing with TCP/IP 497

12.6.1 SMDS Bridging with TCP/IP 497

12.7 Performance 499

12.7.1 Availability 501

12.7.2 Delay 502

12.7.3 Accuracy 504

12.7.4 Rellance on Fiber 504

12.7.5 “Smart Applications”Concept 505

12.8 Design Conaiderations 505

12.8.1 Transport 505

12.8.2 Distance Between Nodes 506

12.8.3 Timing 507

12.8.4 Capacity Planning 507

12.8.5 Network Management 508

12.8.6 Future PARs 508

12.8.7 Migration Path from SMDS to ATM 509

12.9 Review 509

Chapter 13.AYM,Part 1 511

13.1 ATM Defined 512

13.2 The Many Faces of ATM——Archltecture,Technology,and Service 513

13.2.1 As an Interface and Protocol 513

13.2.2 As a Technology 513

13.2.3 As Economical,Integrated Access 513

13.2.4 As an Infrastructure 514

13.2.5 As a Service 514

13.3 The ATM Cell and Transmission 514

13.3.1 ATM Cell 514

13.3.2 Cell Segmentation Example 516

13.3.3 Why 53 Bytes? Choice of Payload Size 518

13.4 ATM Networking Basics 519

13.4.1 Transmission Path,Virtual Path,and Virtual Channel Analogy 519

13.4.2 Transmission Path,Virtual Path,and Virtual Channels 521

13.4.3 Virtual Path Connections(VPCs)and Virtual Channel Connections(VCCs) 523

13.5 Theory of Operation 524

13.5.1 A Simple ATM Example 524

13.5.2 An ATM Switch Example 524

13.6 B-ISDN Protocol Reference Model 527

13.7 The Plane-Layer Truth——An Overview 528

13.8 Physical(PHY)Layer 530

13.8.1 Physical Medium Dependent(PMD)Sublayer 530

13.8.2 Transmission Convergence(TC)Sublayer 532

13.8.3 Exampies of TC Mapping 532

13.8.4 TC Header Error Check(HEC)Functions 534

13.8.5 TC Cell Rate Decoupling 534

13.9 ATM Layer——Protocol Model 536

13.9.1 Physical Llnks and ATM Virtual Paths and Channels 536

13.10.1 ATM UNI and NNI Defined 538

13.10 ATM Layer and Cell——Definition 538

13.10.2 ATM UNI Cell Structure Detailed 539

13.10.3 ATM NNI Cell Structure Detailed 540

13.10.4 Definition of ATM Cell Heeder Fields 541

13.10.5 Relaying and Multiplexing Using the VPVVCI 541

13.10.6 Meaning of Preassigned Reserved Header Values 542

13.10.7 Meaning of the Payload Type(PT)Field 542

13.10.8 Meaning of the Cell Loss Priority(CLP)Field 542

13.11 The Traffic Contract and Quality of Service(QOS) 543

13.11.1 Reference Model 544

13.11.2 Quality of Service Parameters 545

13.11.3 QoS Classes 547

13.11.4 Specified QoS Clasaes 548

13.11.5 Unspecified QoS and“Bast-Effort”Service 549

13.12 Traffic Descriptor 550

13.13 Traffic and Congestion Control Dafined 552

13.14 Methods of Congestion Control 552

13.15 Review 553

Chapter 14.ATM,Part 2 555

14.1 ATM Adaptation Layer(AAL)——Protocol Model 556

14.1.1 The AAL Protocol Structure Defined 556

14.1.2 AAL Service Attrlbutes Classified 557

14.1.3 ATM Adaptation Layer(AAL)——Definition 558

14.2 User Plane Overview 565

14.2.1 User Plane——SSCS Protocols 565

14.2.2 User Plane——Higher Layers 566

14.2.3 Frame Relay over ATM 566

14.2.4 SMDS Access Interworking over ATM 570

14.3.1 Control Plane Overvlew 572

14.3.2 Control Plane Architecture and Signaling 572

14.3 Control Plane AAL 572

14.3.3 Control Plane Addressing and Routing Defined 573

14.3.4 ATM Layer VP/VCI Level Addressing 574

14.3.5 ATM Control Plane(SVC)Addressing 575

14.3.6 Basic Routing Requirements and Attributes 576

14.3.7 A Simple ATM Layer VCC Routing Design 576

14.3.8 Control Plane Protocol Model 577

14.3.9 Control Plane——Signallng Functions 579

14.4 Management Plane 580

14.4.1 Layer Management 581

14.4.2 Plane Management 582

14.5 Data Exchange Interface(DXI) 582

14.5.1 ATM DXI——Mode 1a and Mode 1b 583

14.5.2 ATM DXI——Mode 2 584

14.5.3 ATM DXI Header Formats 585

14.5.4 Local Management Interface(LMI)Summarized 586

14.5.5 Frame Relay User-to-Network Interface(FUNI) 586

14.6 ATM Public Services 587

14.6.1 Public ATM Network Architectures 587

14.6.2 ATM Service Suite 587

14.6.3 Public ATM Services and Providers 588

14.7 Challenges 589

14.8 Review 591

Chapter 15.SONET 593

15.1 Terms Defined 593

15.2 Standards 595

15.2.1 Phase I 595

15.2.2 Phase II 595

15.3.1 Basic Structure 596

15.3 SONET Structure 596

15.2.3 Phase III 596

15.3.2 SONET Hierarchy 597

15.3.3 Multiplexing 597

15.3.4 SONET Architecture Layers 599

15.3.5 SONET Protocol Stack 600

15.3.6 OC-N Midspan Flber Meet 600

15.3.7 Data Communications Channels(DCC) 602

15.4 Frame Format and OAM Elements 602

15.4.1 Basic Frame Format 603

15.4.2 Payload 604

15.4.3 Virtual Tributary 606

15.4.5 Overhead and the Control Field 608

15.4.6 Bit Interleave Parity Check(BIP-8) 611

15.4.7 Bit Stuffing 611

15.5 SONET Hardware 612

15.4.8 OAM Structure 612

15.5.1 SONET Terminating Multlplexers 613

15.5.2 SONET Concentrators 615

15.5.3 SONET Add/Drop Multiplexer(SADM) 615

15.5.4 SONET Digital Loop Carrier Systems(DLCs) 617

15.5.5 SONET Digital Cross-Connects(SDXCs) 617

15.5.6 SONET Broadband Switches 620

15.5.7 SONET Regenerators and Optical Amplifiers 620

15.5.8 SONET Equipment Vendors 621

15.6 Interfaces 621

15.6.1 Interface Options 621

15.6.2 User Access 622

15.6.3 Services Support 623

15.7 Advantages and Disadvantages 623

15.8 Performance and Design Considerations 625

15.9 Review 626

Part 5 Requirements,Planning,and Choosing Technology 627

Chapter 16.Requirements Definition 629

16.1 User Requirements——The User s Viewpoint 629

16.1.1 User Expectations and Satisfaction 630

16.1.2 Usar Involvement in Technology 633

16.2 User Requirements——The Designer s Viewpoint 633

16.3 Traffic Sizing 633

16.3.1 Message or Data Size Basics 634

16.3.2 Tuning Data Size across the Network 635

16.4 Traffic Characteristics Defined 635

16.4.1 Traffic Burstiness 635

16.4.2 Traffic Delay Tolerance 636

16.4.3 Response Time 636

16.4.4 Capacity and Throughput 636

16.4.6 Sessions and Usage Patterns 637

16.4.5 Application Traffic Attributes Summarized 637

16.4.7 Call Setups per Second and Response Time 639

16.4.8 Routing 641

16.4.9 Data Accuracy(Minimum Errors) 642

16.4.10 Priorltization 642

16.4.11 Application Quality of Service(QoS)Requirements 643

16.5 Protocols 644

16.5.1 Connection/Session Oriented 644

16.5.2 Protocol Routing 645

16.5.3 Application Architecture 645

16.5.4 Addressing and Naming Schemes 645

16.6 Time and Delay Considerations 646

16.6.1 Access Time 646

16.6.2 Response Time 647

16.6.4 Performance——Packet-per-Second Processing,Forwarding,and Filtering 648

16.6.3 Delay versus Throughprt 648

16.6.5 Blocking versus Storage versus Queuing 649

16.6.6 Interrupts and Resets 650

16.6.7 Congestion 650

16.7 Connectivity 651

16.7.1 User-to-Network and Network-to-Network Connectivity 651

16.7.2 Geographical Requirements 652

16.7.3 Structure——Central versus Distribted 652

16.7.4 Current Infrastructure 652

16.7.5 Remote Access 653

16.8 Availability,Reliability,and Maintainability 654

16.9 Amount of User Control 655

16.11 Service Aspects 656

16.11.1 Network Management 656

16.10 Expandability,Scalability,and Evolution 656

16.11.2 Billing 657

16.11.3 Redundancy and Disaster Recovery 657

16.11.4 Security 657

16.11.5 User Support 658

16.12 Budget Constraints 658

16.13 Politics 659

16.14 Review 659

Chapter 17.Traffic Engineering and Capacity Planning 661

17.1 Throughput Calculations 662

17.1.1 Packets,Frames,Cells per Second 662

17.1.2 Effects of Overhead 663

17.2 Traffic Engineering Basics——Traffic Characteristics and Source Models 664

17.2.1 Source Model Traffic Parameter Characteristics 665

17.2.2 General Source Model Parameters 665

17.2.3 Poisson Arrivals and Markov Processes 666

17.3 Traditional Traffic Engineering 669

17.3.1 Statistical Behavior of User Traffic 669

17.3.2 Voice Traffic Modeling(Erlang Analysis) 670

17.4 Queued Data and Packet-Switched Traffic Modeling 671

17.4.1 Queueing System Models Notation 672

17.4.2 Queued Data and Packet-Switched Traffic Modeling 672

17.4.3 Markovian Queueing Systems Models 673

17.4.4 Utllization and Capacity Calculations 674

17.4.5 Markovian Queueing Packet Switching System Example 676

17.4.6 Bemoulli Processes and Gaussian Approximation 677

17.4.7 Traffic Engineering Complexlties 679

17.4.8 Buffer Overflow and Performance 679

17.4.9 Cell Buffer Overflow Analysis 680

17.4.10 Statistical Multiplexing Gaih 683

17.4.11 LAN Traffic Modeling 687

17.4.12 DQDB Traffic Modeling 688

17.5 Dasigning for Peaks 690

17.5.1 Standard Busy Hour Calculations 691

17.5.2 Data Equivaient of Busy Hour 692

17.6 Delay 692

17.6.1 Causes of Delay 693

17.6.2 Circuit-,Message-,Packet-,and Cell-Switching Delay Basics 693

17.6.3 Impact of Delay on Applications 695

17.6.4 Impact of Loss on Applications 697

17.6.5 Data Services Delay 699

17.7 Availability and Reliability 700

17.7.1 Availability 701

17.7.2 Reiiability 703

17.7.4 Plan for Failures 704

17.7.3 Additional Performance Measurements 704

17.8 Reaction to Extreme Situations 705

17.9 Network Performance Modeling 706

17.10 Creating the Traffic Matrix 707

17.10.1 Asymmetric versus Symmetric Distribution 707

17.10.2 Creating the Traffic Matrix 708

17.10.3 Interpreting the Matrix 710

17.11 Capacity Planning and Network Vision 711

17.12 Review 712

Chapter 18.Technology and Service Comparisons 715

18.1 Circuit-,Message-,Packet-,and Cell-Switching Methods 715

18.1.1 A Taxonomy of Data Communication Methods 716

18.1.2 Dedicated or Switched Networks? 717

18.2.3 Traffic,Congestion,and Flow Control 719

18.2.2 Switching Approach 719

18.2.1 Data Delivery Philosophy 719

18.2 Packet-Switching Service Aspects 719

18.2.4 Comparlson of Protocol Functions 720

18.2.5 OSI Functional Mapping 720

18.3 Generic Packet-Switching Network Characteristics 721

18.3.1 Network-Addressing Philosophies 721

18.3.2 Routing Approaches 722

18.3.3 Network Access and Topology 722

18.3.4 Protocol-Speclfic Functions 722

18.3.5 Summary of Networking Aspects 723

18.4 Private versus Public Networking 723

18.5 Public Network Service Selection 725

18.5.1 When Do You Need a Private Line? 725

18.5.2 When Do You Need X.25 Service? 726

18.5.3 When Do You Need FR Service? 726

18.5.6 When Do You Need a Public Data Service? 727

18.5.4 When Do You Need SMDS? 727

18.5.5 When Do You Need ATM? 727

18.5.7 Transport Tranamission Characterlstics 728

18.6 Business Aspects of Packet-,Frame-,and Cell-Switching Services 729

18.6.1 Efficiency versus Features 729

18.6.2 CPE Hardware and Software Impacts 731

18.6.3 Integration Savings 732

18.6.4 Ubiquity and Market Demand 732

18.6.5 General Pricing Structures 733

18.6.6 Private Line Pricing Example 735

18.6.7 Frame Relay Pricing Example 735

18.6.10 Summary of Business Aspects 737

18.7 High-Speed LAN Protocols Comparison 737

18.6.9 ATM Pricing Example 737

18.6.8 SMDS Pricing Example 737

18.8 Application Performance Needs 738

18.8.1 Throughput 739

18.8.2 Burstiness 740

18.8.3 Response Time and Delay Tolerance 740

18.9 Review 742

Part 6 Choosing the Service Provider 743

Chapter 19. The Service Provider Selection Process 745

19.1 The Request for Information(RFI) 746

19.2 The Request for Proposal(RFP)Process 747

19.2.1 The RFP Structure 747

19.2.2 The Sample Network(s) 748

19.2.3 Solicitation 749

19.2.4 Analyzing and Evaluating the RFP Response 749

19.3 Choosing the Vendor(s) 750

19.3.1 The Requirements Matrlx and Weighting Methods 751

19.3.2 What Tradeoffs are Critical? 752

19.3.3 Public Service Network Offerings versus Private Networks 755

19.3.4 Adherence to Industry Standards 756

19.3.5 Vendor Promises and Support 756

19.3.6 Vendor Expertise 757

19.3.7 Vendor Ddlivery Dates and Reality 757

19.3.8 Product Announcements and Product Futures 758

19.3.9 The Proprietary Vendor and Futures 758

19.4 The Vendor-Designer Relationshlp 758

19.5 Strateglc User-Vendor Agreements 759

19.6 Service Levels 760

19.7 Network and Systems Management Capabllities 761

19.8 Future Business of Your Company 763

19.9 Review 763

Part 7 Network Design and Management 765

Chapter 20. Access Network Design 767

20.1 Access and Backbone Level Design Defined 767

20.1.1 User or Application Layer Design 767

20.1.2 Access Layer Design 769

20.1.3 Backbone Layer Design 769

20.2 Network Access Requirements 769

20.2.1 Interface and Physical Connectivity 770

20.2.2 Protocois 771

20.2.3 Architecture and Technology 773

20.2.4 Features,Functions,and Services Required 773

20.2.5 Traffic Prloritization at the Access Device 774

20.3 Access Network Capacity Requirements 775

20.3.1 Access Device Loading and Link Utllization Prlnciples 775

20.3.2 Access Node Design 777

20.3.3 Utilization,Loading Factors,and Anticipating Failures 779

20.3.4 Efficiencies of Statistlcal Multiplexing 781

20.3.5 Future Capacity 782

20.4 Sytle 782

20.4.1 Based on Geography 782

20.4.2 Ubiquitous Access(Matrix) 783

20.4.3 Hierarchical 783

20.4.4 Hierarchical versus Ubiquitous Access 785

20.4.5 Collapsed Backbone 786

20.4.6 LAN Switching Migrations to ATM 787

20.5 Completing the Access Network Design 791

20.5.1 User/Application Intelligence Verification 792

20.5.2 Access-Device Level 793

20.5.3 Number and Type of Access Nodes 793

20.5.4 Access Circuit Topology and Design 794

20.5.5 Access Network Topologies 795

20.6 Diverse,Remote,and Telecommuting Options 796

20.6.1 Access Diverslty Alternatives 796

20.6.2 Remote Access Alternatives 797

20.6.3 Telecommuting Options 799

20.7 Integrated Access 800

20.8 Review 800

Chapter 21. Backbone Network Design 803

21.1 Backbone Requirements 803

21.1.1 Interfaces 804

21.1.2 Protocols 805

21.1.3 Architecture and Technology 806

21.1.4 Features,Functions,and Services 808

21.2.1 Backbone Node Selection 809

21.2 Backbone Natwork Capacity Required 809

21.2.2 Utilization,Loading Factors,and Anticipating Fallures 811

21.2.3 Total Backbone Capacity 811

21.2.4 Route Determination 814

21.2.5 Future Capacity 815

21.3 Styles of Topologies 817

21.3.1 Star 817

21.3.2 Loop 817

21.3.3 Meshed and Fully Meshed 819

21.3.4 Daisy-Chained Access Nodes 819

21.3.5 Backbones Within Backbones 821

21.4 Backbone Topology Strategies 823

21.4.1 Desirable Topoiogies per Technology 824

21.4.2 Requirements Drive the Topology 824

21.4.4 Topology of the Future-Distributed Design 826

21.4.3 Hybrid Topologies 826

21.5 Network Management 827

21.6 Total Network Tlming 827

21.7 Tuning the Network 827

21.7.1 Optimizing Packet/Frame/Call Size 828

21.7.2 Limiting Protocol Segmentation 829

21.7.3 Port-to-Port Data Transfer Delay 830

21.7.4 Window Sizes 830

21.7.5 Bursting 830

21.8 Review 832

Chapter 22. Addressing and Routing Design 833

22.1 Overview of Addressing 833

22.1.1 Levels of Addressing 834

22.1.2 Types of Addresses 834

22.1.3 Address Assignment and Resolution 835

22.3 IP Address Design Primet 836

22.2 IP Address Design 836

22.3.1 Netowrk Mask 837

22.3.2 IP Address Topologies 838

22.3.3 Addresses Based on Toplogy 839

22.3.4 Subnet Masks 840

22.3.5 Variable Length Subnet Masks 843

22.3.6 Design Rules-Subnets and Frame Relay 845

22.3.7 OSPF versus RIP and Default Gateways 845

22.3.8 Mask Effect on Higher-Layer Protocols 846

22.4 Novell IPX Addressing 846

22.4.1 IPX Addreas Structure 847

22.4.2 Designing IPX WANs 847

22.5 Address Management 848

22.7 Review 849

22.6 Classiess InterDomain Routing(CIDR) 849

Chapter 23. Operations and Network Management 851

23.1 Documentation 851

23.1.1 The EngIneering Plan 852

23.1.2 The O M Document 852

23.2 Organizational Responsibillties 853

23.3 Operations,Administration,Maintenance,and Provisioning(OAM P)Defined 855

23.3.1 The OAM P Functional Model 855

23.3.2 Operations Defined 857

23.3.3 Administration 857

23.3.4 Maintenance 857

23.3.5 Provisioning 858

23.3.6 Centrallzed versus Distrlbuted Network Management 858

23.4.1 Users Demand Better Network Management 859

23.4 Network Management Defined 859

23.4.2 Evolution of Network Element Management 860

23.4.3 Network Management Architectures 861

23.5 OSI Network Management Functional Model 861

23.5.1 Vendor Network Management versus OSI and CMIP(CMCL/CMIS) 863

23.5.2 OSI CMIS/CMIP Upstaged by Simple Network Management Protocol(SNMP) 864

23.5.3 New Technology Outpaces Official Standards 865

23.6 ITU Telecommunications Management Network(TMN) 865

23.7 SNMP Defined 867

23.7.1 SNMP Structure and MIBs 867

23.7.2 SNMPv2 868

23.7.3 Customer Network Management and Proprietary Operating Systems 869

23.7.4 IBM Network Management-NewView 869

23.7.5 Reporting Formats 869

23.8 Remote Monitoring(RMON) 870

23.9 Trends in Network Management 872

23.9.1 Will the ISO OSI NM Standards Follow SNMP s Example? 872

23.9.2 Network Management Elements and New T?chnologies 873

23.9.3 Around-the-Clock Operations Increasing 874

23.9.4 Multivendor,Multitransport Media Networking Growing 875

23.9.5 Improvements in Display Management 877

23.9.6 Artificial Intelligence(AI)/Neural Networks 878

23.9.7 Voice Processing and Network Management 879

23.10 Billing 879

23.11 Security 879

23.12 Training 881

23.13 When to Stop Designing and Start Implementing 881

23.14 Review 882

Chapter 24. Design and Management Tools 883

24.1 Design Tools 883

24.3 Categorles of Tools 884

24.2 Terminology 884

24.3.1 Design Tools 885

24.3.2 Configuration-Management Tools 885

24.3.3 Event-Management Tools 886

24.4 Classes of Design Tools 886

24.4.1 Physical-Design Tool 886

24.4.2 Logical-Design Tool 887

24.4.3 Statistical-Design Tools 887

24.4.4 Integration of the Physical,Logical.and Statistical 889

24.5 Components of Design Projects 889

24.5.1 Visualize 890

24.5.2 Simulate 890

24.5.3 Characterize 890

24.5.4 Optimize 890

24.5.7 Report 891

24.5.5 Design 891

24.5.6 Test 891

24.5.8 Performance Analysls 892

24.6 Types of Design Projects 892

24.7 Requirements 892

24.7.1 User Inputs 893

24.7.2 Tool Support 893

24.7.3 Reporting Capabillty 894

24.7.4 User Functionality 895

24.7.5 Private Line Customer Network Design Requirements 896

24.7.6 Frame Relay Customer Network Design Requirements 896

24.7.7 Multiprotocol Customer Network Design Requirements 896

24.7.8 Customization Requirements 897

24.8 Commercial Tools 898

24.8.1 NetMaker XA from Make Systems 898

24.7.9 Other Requirements 898

24.8.2 BONES 900

24.8.3 Wandl 901

24.8.4 COMNET III from CACI Products Company 902

24.8.5 OPNET Modeler from MIL 3 903

24.8.6 PIANYST from IRI 904

24.9 Summary of Design Tools 905

24.10 How Oftan to Optlmize? 905

24.11 Review 905

Chapter 25. International Networks 907

25.1 International Data Network Types 907

25.2 The Changing Roie of PTTs 908

25.2.1 Woridwide Divestiture and the User 910

25.2.2 Dominant Public Providers and PTT3 911

25.2.3 The PTTs and Global Players after 1992 911

25.3.2 Importance of Location 913

25.3 Transmission Networks 913

25.3.1 Expensive,Poor Facilities in Developing Areas 913

25.3.3 Costs 914

25.4 The IVAN/IVPDN Market 914

25.4.1 Foreign Service Providers 914

25.4.2 International Outsourcing and Joint Partnerships 915

25.5 International Design 915

25.6 Review 916

Appendix A Acronyms and Abbreviations 917

Appendix B Standards Sources 927

Appendix C IP Mask Reference Table 931

Appendix D IP Network Addressing Reference 933

Glossary 937

Bibliography 955

Index 959