数据通信与网络教程 第3版 英文版PDF电子书下载

CHAPTER 1 INTRODUCTION TO COMMUNICATIONS,STANDARDS,AND PROTOCOLS 1

1.1 WHY STUDY COMMUNICATIONS? 1

A Brief History 1

Applications 4

Issues 8

1.2 COMPUTER NETWORKS 9

Common Bus Topology 10

Star Topology 11

Ring Topology 12

Fully Connected Topology 13

Combined Topologies 13

1.3 STANDARDS AND STANDARDS ORGANIZATIONS 15

The Need for Standards 15

Standards Organizations 16

1.4 OPEN SYSTEMSAND THE OSI MODEL 18

CONTENTSPREFACE 19

Overview of the Model 22

Connection Strategies 24

Physical Layer 29

Data Link Layer 30

Network Layer 32

Transport Layer 33

Session Layer 36

Presentation Layer 38

Application Layer 40

Summary 42

Internet Layers 42

1.5 THE FUTURE OF DATA COMMUNICATIONS 44

REVIEW QUESTIONS 51

EXERCISES 52

REFERENCES 53

CHAPTER 2 TRANSMISSION MEDIA AND CODES 54

2.1 INTRODUCTION 54

2.2 CONDUCTIVE METAL 57

Twisted Pair 57

Coaxial Cable 59

2.3 OPTICAL FIBER 61

2.4 WIRELESS COMMUNICATIONS 66

Microwave Transmission 67

Satellite Transmission 70

Geosynchronous Satellites 71

Low Earth Orbit Satellites 77

Wireless LANs 81

Bluetooth 82

Free Space Optics 83

Summary 84

2.5 CODES 87

Early Codes 87

ASCII Code 89

EBCDIC Code 92

Unicode 92

2.6 SUMMARY 93

REVIEW QUESTIONS 94

EXERCISES 95

REFERENCES 96

CHAPTER 3 ANALOG AND DIGITAL SIGNALS 97

3.1 INTRODUCTION 97

3.2 DIGITAL ENCODING SCHEMES 98

NRZ Encoding 98

Manchester Encoding 100

3.3 ANALOG SIGNALS 101

Fourier's Results 103

Applications of Fourier's ResUlts 106

3.4 BIT RATE 107

The Nyquist Theorem and Noiseless Channels 107

Noisy Channels 109

Shannon's Result 110

3.5 DIGITAL-TO-ANALOG CONVERSION 112

Frequency Modulation 113

Amplitude Modulation 114

Phase Modulation 114

Quadrature Amplitude Modulation 115

3.6 ANALOG-TO-DIGITAL CONVERSION 118

Pulse Amplitude Modulation 119

Pulse Code Modulation 119

3.7 MODEMS 121

Signal Constellation 122

Modem Standards 125

Cable Modems 127

3.8 DSL 131

How It Works 132

ADSL Lite(G.Lite,ITU standard TTU G.992.2) 135

Different DSL Technologies 135

SDSL 136

HDSL and HDSL2 136

SHDSL 137

RADSL 137

IDSL 137

VDSL 137

3.9 SUMMARY 138

REVIEW QUESTIONS 139

EXERCISES 141

REFERENCES 143

CHAPTER 4 MAKING CONNECTIONS 144

4.1 INTRODUCTION 144

The Telephone System 145

4.2 COMMUNICATION CARRIERS AND DEVICES 145

Call Routing 147

Private Branch Exchanges 148

Cellular Phones 149

Fax Machines 151

4.3 TRANSMISSION MODES 153

Serial and Parallel Transmission 153

Asynchronous,Synchronous,and Isochronous Transmission 154

Simplex,Half-Duplex,and Full-Duplex Communications 158

4.4 INTERFACE STANDARDS 159

EIA-232 Interface 160

EIA-232 Subsets 162

Null Modems 163

X.21 Interface 164

USB Connections 166

USB 166

Data Transfer 168

USB Packets 170

Fire Wire 172

Connections 173

Communications 175

Arbitration 176

4.5 MULTIPLEXING 178

Frequency-Division Multiplexing 180

Time-Division Multiplexing 182

Statistical Multiplexers 183

Wave-Division Multiplexing 185

T1 186

4.6 DIGITAL CARRIERS 186

SONET 188

Device Types 189

Payloads and Frames 191

4.7 CONTENTION PROTOCOLS 195

Aloha Protocols 196

Carrier Sense Multiple Access 199

Collision Detection 202

Collision Avoidance 205

Token Passing 205

Summary of Protocols 207

4.8 SUMMARY 207

REVIEW QUESTIONS 210

EXERCISES 212

REFERENCES 214

CHAPTER 5 DATA COMPRESSION 215

5.1 INTRODUCTION 215

5.2 FREQUENCY-DEPENDENT CODES 217

Huffman Code 217

Arithmetic Compression 220

5.3 RUN-LENGTH ENCODING 225

Runs of the Same Bit 225

Runs with Different Characters 226

Facsimile Compression 226

5.4 RELATIVE ENCODING 229

5.5 LEMPEL-ZIV COMPRESSION 229

Image Representation 235

5.6 IMAGE COMPRESSION 235

JPEG Compression 238

DCT Phase 238

Encoding Phase 244

GIFFiles 245

5.7 MULTIMEDIA COMPRESSION 246

MPEG 246

MP3 251

5.8 SUMMARY 254

REVIEW QUESTIONS 254

EXERCISES 255

REFERENCES 257

CHAPTER 6 DATA INTEGRITY 258

6.1 INTRODUCTION 258

Parity Checks 259

6.2 SIMPLE ERROR DETECTION TECHNIQUES 259

Analysis of Parity Checking 260

Checksums 261

6.3 CYCLIC REDUNDANCY CHECKS FOR ERROR DETECTION 261

Polynomial Division 262

How CRC Works 263

Analysis of CRC 265

CRC Implementation Using Circular Shifts 268

6.4 HAMMING CODES:ERROR CORRECTION 270

Single-Bit Error Correction 270

Multiple-Bit Error Correction 273

6.5 SUMMARY 274

REVIEW QUESTIONS 275

EXERCISES 276

REFERENCES 277

CHAPTER 7 DATA SECU RITY 279

7.1 INTRODUCTION 279

7.2 ENCRYPTION ALGORITHMS 281

Caesar Cipher 282

Polyalphabetic Cipher 284

Transposition Cipher 284

Bit-Level Ciphering 285

Data Encryption Standards 287

DES 287

Triple DES 291

AES and the Rijndael Algorithm 292

Clipper Chip and the Skipjack Algorithm 296

7.3 KEY DISTRIBUTION AND PROTECTION 299

Diffie-Hellman Key Exchange 300

Shamir's Method 300

7.4 PUBLIC KEY ENCRYPTION 302

RSA Algorithm 302

Digital Signatures 305

Authentication and Message Digests 308

Pretty Good Privacy 311

7.5 TRANSPORT LAYER SECURITY AND SERVER AUTHENTICATION 315

Transport Layer Security 316

X.509 Certificate 317

Handshakes 320

7.6 FIREWALLS 323

Packet Filtering 324

Application-Level Gateway 325

Stateful Inspection 327

7.7 VIRUSES 329

Infecting Files 330

Memory-Resident Viruses 332

Virus Evolution 333

Virus Sources 335

7.8 THREATS AND ATTACKS 336

The Internet Worm 336

Computer Hackers 338

Other Threats 339

7.9 SUMMARY 341

REVIEW QUESTIONS 345

EXERCISES 346

REFERENCES 348

8.1 INTRODUCTION 350

CHAPTER 8 FLOW CONTROL 350

8.2 SIGNALING 352

DTE-DCE Flow Control 353

X-ON/X-OFF 353

8.3 FRAME-ORIENTED CONTROL 354

Unrestricted Protocol 355

Stop-and-Wait Protocol 356

Protocol Efficiency 358

8.4 Go-BACK-n:A SLIDING WINDOW PROTOCOL 360

Frame Format 362

Features 363

Algorithm 366

Features 370

8.5 SELECTIVE REPEAT:A SLIDING WINDOW PROTOCOL 370

Algorithm 374

8.6 EFFICIENCY OF SLIDING WINDOW PROTOCOLS 377

8.7 PROTOCOL CORRECTNESS 380

Finite State Machines 380

STD for a Simplified Go-Back-n Protocol 381

State Transition Diagram for a Faulty Go-Back-n Protocol 383

Petri Nets 386

8.8 SUMMARY 390

REVIEW QUESTIONS 392

EXERCISES 393

REFERENCES 395

CHAPTER 9 LOCAL AREA NETWORKS 396

9.1 INTRODUCTION 396

9.2 DATA LINK CONTROL 398

High-level Data Link Control Protocol 400

Frame Format 402

HDLC Example 405

Binary Synchronous Communications Protocol 408

9.3 ETHERNET:IEEE STANDARD 802.3 410

Concepts 411

Ethernet Frame Format 413

Physical Implementations of 10 Mbps Ethernet 415

9.4 FAST ETHERNET(100 MBPS) 417

100BaseTX 418

100BaseFX 421

100BaseT4 422

9.5 GIGABIT ETHERNET 424

Collision Domain 424

MAC Sublayer 425

1000BaseX 427

1000BaseT 428

Beyond Gigabit Rates 430

9.6 TOKEN RING:IEEE STANDARD 802.5 433

Token and Frame Formats 434

Reserving and Claiming Tokens 436

Ring Maintenance 440

9.7 WIRELESS NETWORKS:IEEE STANDARD 802.11 443

Infrared and Radio Waves 444

Contention 447

Addressing 449

Frame Format 451

Wired Equivalent Privacy 453

Variations of 802.11 454

9.8 SUMMARY 455

REVIEW QUESTIONS 457

EXERCISES 459

REFERENCES 461

CHAPTER 10 CONNECTING NETWORKS 462

10.1 INTRODUCTION 462

10.2 LAYER 1 CONNECTIONS 465

Repeaters and Hubs 465

10.3 LAYER 2 CONNECTIONS 467

Bridges 467

Bridging Different Types of LANs 468

Routing Tables 469

Routing 469

Transparent Bridges 471

Route Learning 471

Frame Propagation 473

Spanning Tree Algorithm 475

Source-Routing Bridges 479

Switches and Switched Ethernet 480

Virtual LANs 484

10.4 LAYER 3 CONNECTIONS 487

Routing Tables 488

Centralized Routing 490

Distributed Routing 491

Static Routing 492

Adaptive Routing 492

10.5 DIJKSTRA'S ALGORITHM 493

10.6 THE BELLMAN-FORD ALGORITHM 496

Problems with the Bellman-Ford Algorithm 500

10.7 ADDITIONAL ROUTING METHODS 502

Link State Routing 502

Hierarchical Routing 503

Routing Information Protocol 506

Open Shortest Path First 509

Border Gateway Protocol 510

Summary of Routing Techniques 512

10.8 CONGESTION AND DEADLOCK 512

Congestion 512

Deadlock 515

10.9 SUMMARY 517

REVIEW QUESTIONS 519

EXERCISES 520

REFERENCES 523

CHAPTER 11 INTERNET PROTOCOLS AND APPLICATIONS 524

11.1 INTRODUCTION 524

11.2 INTERNET PROTOCOL 525

Overview of TCP/IP 526

Interrnet Addressing 528

Classless Addresses 531

Obtaining an Address 533

Domain Name System 534

IP Packets 537

Fragmentation 540

IP Routing 541

Routers 546

Multicast Routing 549

Resource Reservation Protocol 555

Internet Control Message Protocol 557

11.3 IPv6 559

IP Shortcomings 560

Packet Headers 561

IPSec 564

IPv6 Addressing 566

Compatibility with IPv4 569

Summary 570

11.4 TRANSPORT PROTOCOLS 571

Transmission Control Protocol 573

TCP Segment 574

Connection Management 577

Flow Contol 580

Congestion Control 582

User Datagram Protocol 584

Real-Time Transfer Protocol 585

11.5 INTERNET APPLICATIONS 589

Virtual Terminal Protocols 589

Telnet 590

Secure Shell 593

File Transfers 596

FTP 597

Secure Copy 600

Simple Mail Transfer Protocol 600

Simple Network Management Protocol 604

Management Information Base 605

SNMP Commands 606

11.6 SUMMARY 608

REVIEW QUESTIONS 610

EXERCISES 612

REFERENCES 614

CHAPTER 12 INTERNET PROGRAMMING 616

12.1 INTRODUCTION 616

12.2 SOCKET PROGRAMMING 617

Sockets 618

Client/Server Model 619

Socket Data Structures 620

Client/Server Example 621

Socket Commands 621

Client Source Code 624

Server Source Code 631

12.3 WORLD WIDE WEB 633

Web Page Access 634

Hypertext Markup Language 636

Tags 637

HTML Forms 641

Client-Side Programming and JavaScript 644

12.4 COMMON GATEWAY INTERFACE AND SERVER-SIDE PROGRAMMING:SETTING UP A SEARCH ENGINE 649

Forms 650

Query Strings 651

Example Search Engine 651

12.5 PERL PROGRAMMING:PIZZA ORDERING SYSTEM 654

Customer Interaction 655

Verifying Phone Numbers 658

Updating Customer Information 665

Placing an Order 668

Verifying the Order 669

12.6 SUMMARY 672

REVIEW QUESTIONS 673

EXERCISES 674

REFERENCES 676

CHAPTER 13 CIRCUIT TECHNOLOGIES 677

13.1 INTRODUCTION 677

13.2 INTEGRATED SERVICES DIGITAL NETWORK 678

Services 679

Architecture 681

Protocols 683

Signaling System 7 684

Basic Service Protocols 686

Call Setup 689

Broadband ISDN 691

13.3 VIRTUAL CIRCUIT PROTOCOLS:X.25 AND FRAME RELAY 692

Packet-Switched Network Modes 693

Virtual Circuits 693

Datagram Service 695

X.25 Interface Standard 696

Packet Format 697

Virtual Calls 698

Frame Relay 699

Frame Format 701

Committed Information Rate 702

Congestion Control 703

13.4 ASYNCHRONOUS TRANSFER MODE 705

Benefits of Small Fixed-Size Cells 706

Overview of ATM Network 708

Switching 709

Banyan Switches 710

Reference Model 712

Cell Definition 713

Header Error Control 714

Cell Loss Priority 716

Payload Type 716

Virtual Circuits and Paths 716

Connection Management 717

Connection Parameters 719

Adaptation Layers 720

AAL1 721

AAL2 723

AAL5 724

Service-Specific Connection-Oriented Protocol 725

Gigabit Ethernet versus ATM 726

13.5 SUMMARY 727

REVIEW QUESTIONS 727

EXERCISES 729

REFERENCES 730

GLOSSARY 731

ACRONYMS 748

INDEX 752