Understanding data communications: from fundamentals to networking

858 Pages·2000·9.605 MB·English

by  Gilbert Held

UnderstandingDataCommunications:FromFundamentalstoNetworking.
ThirdEditionGilbertHeld
Copyright#2000JohnWiley&SonsLtd
PrintISBN0-471-627453OnlineISBN0-470-84148-6
UNDERSTANDING
DATA COMMUNICATIONS
UnderstandingDataCommunications:FromFundamentalstoNetworking.
ThirdEditionGilbertHeld
Copyright#2000JohnWiley&SonsLtd
PrintISBN0-471-627453OnlineISBN0-470-84148-6
UNDERSTANDING
DATA COMMUNICATIONS
FromFundamentals toNetworking
Third Edition
GilbertHeld
4-DegreeConsulting
Macon,Georgia,
USA
JOHN WILEY & SONS, LTD
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UnderstandingDataCommunications:FromFundamentalstoNetworking.
ThirdEditionGilbertHeld
Copyright#2000JohnWiley&SonsLtd
PrintISBN0-471-627453OnlineISBN0-470-84148-6
CONTENTS
Preface xix
Acknowledgements xxi
1 Communications in a Modern Society 1
1.1 Applications 1
1.1.1 Datacollection 2
1.1.2 Transactionprocessing 3
1.1.3 Conversationaltimesharing 5
1.1.4 Remotejobentry 7
1.1.5 Messageswitching 7
1.1.6 Value-addedcarriersandelectronicmail 8
1.1.7 Officeautomation 12
1.1.8 Electroniccommerce 14
1.1.9 Satellitetransmission 16
1.2 Constraints 16
1.2.1 Throughput 17
1.2.2 Responsetime 18
1.2.3 Bandwidth 18
1.2.4 Economics 19
1.3 Emerging Trends 19
1.4 Review Questions 20
2 Basic Telegraph and Telephone Operations 23
2.1 Evolution of Communications 23
2.2 Telegraphy 24
2.2.1 Operation 24
2.2.2 Morsecode 26
2.2.3 Morsecodelimitations 27
2.2.4 Start–stopsignalingandtheBaudotcode 28
2.2.5 Bitsandcodes 29
2.3 Telephony 32
2.3.1 Principleofoperation 32
2.3.2 Soundwaveconversion 34
2.3.3 Thebasictelephoneconnection 36
2.3.4 Switchboardsandcentraloffices 37
2.3.5 Numberingplans 39
2.3.6 Geographiccallingareasandnetworkrouting 40
2.3.7 Theworldnumberingplan 43
2.4 Review Questions 43
vi CONTENTS
3 Basic Circuit Parameters, Measurement Units and
Media Overview 47
3.1 Basic Circuit Parameters 47
3.1.1 Frequencyandbandwidth 47
3.1.2 Thetelephonechannelpassband 49
3.2 Measurement Units 50
3.2.1 Powerratios 50
3.2.2 Signal-to-noiseratio 52
3.2.3 Referencepoints 54
3.3 Media Overview 56
3.3.1 Twisted-paircable 56
3.3.2 Coaxialcable 61
3.3.3 Microwave 63
3.3.4 Fiber-optictransmission 64
3.4 Channel Capacity 67
3.4.1 Bitversusbaud 67
3.4.2 Nyquistrelationship 67
3.4.3 Shannon’slaw 68
3.5 Structured Wiring 69
3.5.1 Thewiringcloset 69
3.5.2 TheEIA/TIA-568standard 69
3.6 Review Questions 72
4 Fundamental Data Transmission Concepts 75
4.1 Analog Line Connections 75
4.1.1 Theanalogswitchedline 76
4.1.2 Analogleasedline 79
4.1.3 Dedicatedline 82
4.1.4 Switchednetworkvsleasedlineeconomics 83
4.2 Types of Service and Transmission Devices 84
4.2.1 Digitalrepeaters 85
4.2.2 Modems 86
4.2.3 Acousticcouplers 87
4.2.4 Analogfacilities 89
4.2.5 Digitalfacilities 93
4.2.6 Digitalsignaling 93
4.2.7 RepresentativeAT&Tdigitalofferings 96
4.3 Transmission Mode 98
4.3.1 Simplextransmission 98
4.3.2 Half-duplextransmission 99
4.3.3 Full-duplextransmission 100
4.3.4 Terminalandmainframecomputeroperatingmodes 101
4.4 Transmission Techniques 103
4.4.1 Asynchronoustransmission 103
4.4.2 Synchronoustransmission 105
4.5 Types of Transmission 106
4.6 Wide Area Network Transmission Structures 107
4.6.1 Mainframecomputer-basednetworkstructure 108
4.6.2 LANnetworkstructure 109
4.6.3 LANinternetworkingstructure 110
4.7 Line Discipline 111
4.8 Transmission Rate 113
4.8.1 Analogservice 113
4.8.2 Digitalservice 114
CONTENTS vii
4.9 Transmission Codes 115
4.9.1 Morsecode 115
4.9.2 Baudotcode 116
4.9.3 BCDcode 116
4.9.4 Extendedbinary-codeddecimalinterchangecode(EBCDIC) 116
4.9.5 ASCIIcode 118
4.10 Review Questions 122
5 Terminals, Workstations and WAN and LAN
Networking Overview 125
5.1 Terminals 126
5.1.1 Interactiveterminalclassification 126
5.1.2 Terminalevolution 127
5.2 Workstations and Other LAN Components 141
5.2.1 Networkinterfacecard 141
5.2.2 Hubs 142
5.2.3 Fileserver 143
5.2.4 Printserver 145
5.2.5 Othertypesofservers 146
5.3 Wide Area Networking Overview 146
5.3.1 Multiplexinganddataconcentration 146
5.3.2 Front-endprocessor 151
5.3.3 Networkconfigurations 151
5.4 Local Area Networking Overview 152
5.4.1 Repeaters 153
5.4.2 Bridges 153
5.4.3 Routers 154
5.4.4 Gateways 155
5.5 Review Questions 157
6 Representative Standards Organizations:
the OSI Reference Model 159
6.1 National Standards Organizations 160
6.1.1 AmericanNationalStandardsInstitute(ANSI) 160
6.1.2 ElectronicIndustriesAssociation(EIA) 161
6.1.3 FederalInformationProcessingStandards(FIPS) 163
6.1.4 InstituteofElectricalandElectronicEngineers(IEEE) 163
6.1.5 BritishStandardsInstitution(BSI) 164
6.1.6 CanadianStandardsAssociation(CSA) 164
6.2 International Standards Organizations 164
6.2.1 InternationalTelecommunicationsUnion(ITU) 164
6.2.2 InternationalStandardsOrganization(ISO) 165
6.3 De facto Standards 167
6.3.1 AT&Tcompatibility 168
6.3.2 Cross-licensedtechnology 169
6.3.3 Bellcore/TelcordiaTechnology 169
6.3.4 Internetstandards 170
6.4 The OSI Reference Model 171
6.4.1 Layeredarchitecture 172
6.4.2 OSIlayers 173
6.4.3 Dataflow 176
6.5 IEEE 802 Standards 177
6.5.1 802committees 177
6.5.2 Datalinksubdivision 179
6.6 Review Questions 180
viii CONTENTS
7 The Physical Layer, Cables, Connectors, Plugs
and Jacks 183
7.1 DTE/DCE Interfaces 184
7.1.1 Connectoroverview 186
7.1.2 RS-232-C/D 188
7.1.3 Differentialsignaling 198
7.1.4 RS-449 200
7.1.5 V.35 202
7.1.6 RS-366-A 203
7.1.7 X.21andX.20 204
7.1.8 X.21bis 207
7.1.9 RS-530 207
7.1.10 HighSpeedSerialInterface 298
7.1.11 HighPerformanceParallelInterface 214
7.1.12 UniversalSerialBus 216
7.1.13 IEEE1394(FireWire) 218
7.2 Cables and Connectors 222
7.2.1 Twisted-paircable 222
7.2.2 Low-capacitanceshieldedcable 223
7.2.3 Ribboncable 223
7.2.4 TheRS-232nullmodem 223
7.2.5 RS-232cablingtricks 225
7.3 Plugs and Jacks 226
7.3.1 Connectingarrangements 228
7.3.2 Telephoneoptions 230
7.3.3 Orderingthebusinessline 231
7.3.4 LANconnectivity 232
7.4 Review Questions 233
8 Basic Transmission Devices: Line Drivers,
Modems, and Service Units 235
8.1 Line Drivers 236
8.1.1 Directconnection 236
8.1.2 Usinglinedrivers 239
8.2 Modem Operations 243
8.2.1 Themodulationprocess 243
8.2.2 Bpsvs.baud 246
8.2.3 Voicecircuitparameters 246
8.2.4 Combinedmodulationtechniques 247
8.2.5 Modeoftransmission 253
8.2.6 Transmissiontechniques 254
8.2.7 Modemclassification 255
8.2.8 Limited-distancemodems 256
8.2.9 Line-typeoperations 257
8.2.10 Reverseandsecondarychannels 257
8.2.11 Equalization 258
8.2.12 Synchronization 260
8.2.13 Multiportcapability 260
8.2.14 Securitycapability 261
8.2.15 Multiplespeedselectioncapability 261
8.2.16 Voice/datacapability 262
8.2.17 Modemhandshaking 262
8.2.18 Self-testingfeatures 263
8.2.19 Modemindicators 265
8.2.20 Modernoperationsandcompatibility 265
CONTENTS ix
8.3 Intelligent Modems 289
8.3.1 Hayescommandsetmodems 289
8.3.2 Keyintelligentmodemfeatures 296
8.3.3 MicrocomNetworkingProtocol(MNP) 302
8.3.4 Datacompression 306
8.3.5 MNPClass5compression 306
8.3.6 MNPClass7enhanceddatacompression 308
8.3.7 V.42bis 311
8.4 Broadband Modems 312
8.4.1 TelephoneandcableTVinfrastructure 313
8.4.2 Cablemodems 317
8.4.3 DSLmodems 324
8.5 Service Units 330
8.5.1 TheDSU 331
8.5.2 TheCSU 331
8.6 Review Questions 332
9 Regulators and Carriers 335
9.1 Regulators 336
9.1.1 USregulatoryevolution 336
9.1.2 Internationalregulatoryauthorities 342
9.2 Carrier Offerings 343
9.2.1 AT&Tsystemevolution 343
9.2.2 TheBellsystem 345
9.2.3 TheregionalBelloperatingcompanies 346
9.2.4 AT&Tserviceofferings 349
9.2.5 RegionalBelloperatingcompanyofferings 355
9.3 ATM Overview 356
9.4 Review Questions 357
10 Transmission Errors: Causes, Measurements and
Correction Methods 359
10.1 Causes of Transmission Errors 359
10.2 Performance Measurements 360
10.2.1 Biterrorrate 360
10.2.2 Biterrorratetester 360
10.2.3 BERTtime 362
10.2.4 Performanceclassifications 362
10.2.5 Blockerrorratetesting 364
10.2.6 Error-freesecondtesting 365
10.3 Error Detection and Correction Techniques 365
10.3.1 Asynchronoustransmission 365
10.3.2 Synchronoustransmission 370
10.4 Review Questions 374
11 The WAN Data Link Layer 377
11.1 Terminal and Data Link Protocols: Characteristics
and Functions 378
11.1.1 Transmissionsequence 379
11.1.2 Errorcontrol 379
11.2 Types of Protocol 380
11.2.1 Teletypewriterprotocols 380
11.2.2 PCfiletransferprotocols 385
x CONTENTS
11.2.3 Bisynchronousprotocols 395
11.2.4.DigitalDataCommunicationsMessageProtocol(DDCMP) 400
11.2.5 Bit-orientedlinecontrolprocedures 402
11.3 Review Questions 407
12 Increasing WAN Line Utilization 409
12.1 Multiplexers 410
12.1.1 Evolution 410
12.1.2 Devicesupport 410
12.1.3 Multiplexingtechniques 411
12.2 Control Units 439
12.2.1 Controlunitconcept 440
12.2.2 Attachmentmethods 440
12.2.3 Unitoperation 442
12.2.4 Breakingtheclosedsystem 443
12.3 Review Questions 445
13 Local Area Networks 449
13.1 Origin 449
13.2 Comparison with WANs 450
13.2.1 Geographicalarea 450
13.2.2 Datatransmissionanderrorrates 450
13.2.3 Ownership 451
13.2.4 Regulation 451
13.2.5 Dataroutingandtopology 451
13.2.6 Typeofinformationcarried 452
13.3 Utilization Benefits 452
13.3.1 Peripheralsharing 453
13.3.2 Commonsoftwareaccess 453
13.3.3 Electronicmail 453
13.3.4 Gatewayaccesstomainframes 453
13.3.5 Internetaccess 453
13.3.6 Virtualprivatenetworkoperations 454
13.4 Technological Characteristics 454
13.4.1 Topology 454
13.4.2 Comparisonoftopologies 456
13.4.3 Signalingmethods 457
13.4.4 Transmissionmedium 460
13.4.5 Accessmethods 460
13.5 Ethernet Networks 465
13.5.1 Originalnetworkcomponents 465
13.5.2 IEEE802.3networks 468
13.5.3 Framecomposition 490
13.5.4 Mediaaccesscontroloverview 495
13.5.5 Logicallinkcontroloverview 495
13.5.6 OtherEthernetframetypes 498
13.6 Token-Ring 504
13.6.1 Topology 504
13.6.2 Redundantversusnon-redundantmainringpaths 506
13.6.3 Cablinganddevicerestrictions 507
13.6.4 Constraints 510
13.6.5 HighspeedToken-Ring 514
13.6.6 Transmissionformats 515
13.6.7 Mediumaccesscontrol 524
13.6.8 Logicallinkcontrol 527
13.7 Review Questions 528