Emerging communications technologies / Uyless Black.

CONTENIDO
1 Introduction 1
Introduction 1
The Need for Enhanced Services 1
The Past 1
The Future Has Become the Present 3
Goals of the Emerging Communications Technologies 4
LAN Interconnectivity 5
A Brief Summary 5
Need for Greater Communications Capacity 5
LAN and WAN Internetworking 9
Costs of Connecting Dispersed LANs 11
The Virtual Private Network (VPN) 11
Proposed Solutions 14
The Confusion Factor 16
Fast Relay Systems 17
Trends in Technology 19
Hardware and Software 19
New Technologies: To Use Them or Not to Use Them? 22
Broadband Networks 24
Broadband Signaling Hierarchies 24
Applications Supported by the New Technologies 27
New Technologies: Competitive or Complementary? 27
Performance and Distance Considerations 29
Obtaining Services for the Networks: Bandwidth on Demand 31
Where Services are Provided 32
Layered Architectures of the Emerging Technologies 34
Summary 35
2. Foundations for the Emerging Technologies 36
Introduction 36
Virtual Circuits 37
A Brief Digression 38
Permanent Virtual Circuit (PVC) 39
Switched Virtual Circuit (SVC) or Connection on Demand 40
Semi-permanent Virtual Circuits (SPVC) 40
Connection-oriented and Connectionless Systems 41
Connection-orientated Systems 41
Connectionless Systems 41
The Pros and Cons 41
The Coexistence of Connection-oriented Systems and Connectionless Systems 42
Variable Bit Rate (VBR) and Constant Bit Rate (CBR) Applications 43
VBR Applications 43
CBR Applications 43
Flow Control and Congestion Management 45
Explicit Flow Control 45
Implicit Flow Control 45
No Flow Control 45
User Payload Integrity Management 46
Layered Protocols and Protocol Data Units 47
Addressing and Identification Schemes 49
Multiplexing Methodologies 50
Switching, Routing, and Relaying 50
Source and Non-source Routing 51
Fixed and Adaptive Routing 51
Network Interfaces 51
Convergence, Segmentation, and Reassembly Operations 53
Summary 54
3. Emerged Technologies 55
Introduction 55
T1/E1 CARRIER Systems 56
The Purpose of T1 and E1 56
Typical Topology 57
T1 and E1 Layers 58
T1/E1 PDUs 59
Conclusions on T1/E1 60
X.25 61
The Purpose of X.25 61
Typical Topology 61
X.25 Layers 62
X.25 PDUs 63
Other Noteworthy Aspects of X.25 64
Conclusions on X.25 65
ISDN 66
The Purpose of ISDN 66
Typical Topology 67
ISDN Layers 70
ISDN PDUs 71
Conclusions on ISDN 74
Signaling System Number 7 (SS7) 75
The Purpose of SS7 75
Typical Topology 75
SS7 Layers 77
SS7 PDUs 80
Conclusions on SS7 81
FDDI 81
The Purpose of FDDI 81
Typical Topology 82
The FDDI Layers 83
FDDI PDUs 84
Other Notable Aspects of FDDI 85
Conclusion on FDDI 86
Summary 86
4. Frame Relay 87
Introduction 87
The Purpose of Frame Relay 87
Pertinent Standards 88
Typical Frame Relay Topology 89
The Frame Relay Layers 91
Frame Relay and Its Relationship to ISDN Layers 92
OSI and ANSI Layers 94
The Frame Relay Protocol Data Unit (PDU) 95
Frame Relay Operations in More Detail 95
The Frame Relay Core Functions 95
The Data Link Connection Identifier (DLCI) 96
Frame Relay Link Layer Error Checking 98
Potential Congestion Problems 99
Traffic Management 100
Consolidated Link Layer Management (CLLM) 103
The Discard Eligibility Bit 104
Committed Information Rate 105
Leaking CIR and Fast Forward CIR 110
Classes of Service Using Bc and Be 111
DLCIs in More Detail 112
The Frame Relay Network-to-Network Interface (NNI) 114
NNI Operations 114
Bellcore Exchange Access FR (XA-FR) PVC Service 116
Other Notable Aspects of Frame Relay 120
DLCI Values 120
Added Options to Frame Relay 120
The Local Management Interface (LMI) 122
Frame Relay SVC Operations 122
Other Quality of Service (QOS) Options 123
Internetworking Frame Relay and ATM 124
Multiprotocol Operations over Frame Relay 125
The Frame Relay MIB 128
Frame Relay Worksheet 129
Summary 131
5. Fast and Switched Ethernet 132
Introduction 132
Generations of LANs 132
First Generation 133
Second Generation 134
Third Generation 134
Fourth Generation 135
Switched Ethernet 135
Switched Ethernet Architecture 135
Store and Forward and Cut-through Switches 137
Virtual LANs 139
Fast Ethernet 139
100BASET 141
AnyLAN 141
Fast/Switched Ethernet Worksheet 142
Summary 143
6. Metropolitan Area Networks (MANs) and Switched Multimegabit Data Service (SMDS) 144
Introduction 144
The Purpose of a MAN 144
Pertinent Standards 145
A Typical MAN Topology 145
Topology Reconfiguration with Self-Healing Networks 147
The MAN Layers 148
MAN Protocol Data Units (PDUs) 148
MAN Operations in More Detail 149
The Access Unit (AU) 149
Overview of the DQDB Protocol 151
DQDB Counters 152
Location Discovery 154
Segmentation and Encapsulation Operations 155
Other Notable Aspects of the MAN 164
MAN Summary 166
Introduction to SMDS 166
The Purpose of SMDS 166
Pertinent Standards 167
A Typical SMDS Topology 168
SMDS Layers 170
SMDS Protocol Data Units 171
SMDS Operations in More Detail 171
Defining and Measuring Congestion 171
The Sustained Information Rate (SIR) and Access Classes 174
SIP Segmentation and Encapsulation Functions 177
SNI Quality of Service (QOS) Operations 178
The Interchange Carrier Interface (ICI) 179
Quality of Service (QOS) Objectives 180
Other Notable Aspects of SMDS 180
SMDS Address Management Operations 180
The ISSI 181
The Operations System/Network Element (OS/NE) Interface (Operations Technology) 182
The SMDS MIB 184
MAN/SMDS Worksheet 186
SMDS Summary 187
7. Asynchronous Transfer Mode (ATM) 188
Introduction 188
The Purpose of ATM 188
Pertinent Standards 189
An ATM Topology 189
The VPI and VCI Labels 192
ATM Layers 193
ATM and the B-ISDN Model 196
ATM Protocol Data Units (Cells) 198
ATM Operations in More Detail 199
Physical Layer Interfaces 199
ATM over Copper 201
Rationale for the Cell Size 202
Network Transparency Operations 202
ATM Labels 209
Multiplexing VCIs and VPIs 210
ATM Connections on Demand 211
ATM Switching 215
Classes of Traffic 224
AAL Types 227
Traffic Management in an ATM Network 232
ATM Forum and ITU-T Traffic Control and Congestion Control 238
The ATM B-ISDN Intercarrier Interface (B-ICI) 240
Physical Layer Requirements at the B-ICI 243
Traffic Management at the B-ICI 243
Reference Traffic Loads 244
B-ICI Layer Management Operations 245
Other Notable Aspects of ATM 245
Addressing in an ATM Network 245
Network Management 247
The ATM MIB 247
ATM Worksheet 249
Summary 250
8. Synchronous Optical Network (SONET)/Synchronous Digital Hierarchy (SDH) 251
Introduction 251
Purpose of SONET/SDH 251
Synchronous Networks 253
Pertinent Standards 255
Typical SONET/SDH Topology 255
SONET/SDH Layers 260
SONET/SDH in More Detail 262
Automatic Protection Switching (APS) 262
The SDH Multiplexing Structure 263
Payloads and Envelopes 264
Payload Pointers 269
Examples of Payload Mapping 270
Mapping and Multiplexing Operations 275
Error Checking, Diagnostics, and Restoration 277
The Control Headers and Fields 279
SONET/SDH Equipment 285
Other Notable Aspects of SONET/SDH 293
Operation Administration and Maintenance (OAM) Operations 293
Progress in SONET/SDH Penetration 295
SONET/SDH Worksheet 295
Summary 296
9. Mobile Communications Technologies 297
Introduction 297
The Purpose of Mobile Communications Systems 297
Typical Cellular Systems Topology 298
Cellular Systems Operations in More Detail 300
Cellular System Types and Market Penetration 300
GSM 302
GSM Interfaces 304
Call Routing 307
Location Updating 308
GSM 900/DCS1800: Foundation for PCS 1900 (TDMA) 309
CDMA: A New Arrival into the Commercial Mobile, Wireless World 310
TDMA versus CDMA 311
Cordless Systems Operations in More Detail 312
CT2 312
DECT 313
Other Standardization Efforts for PCS 314
The Auctions in the U.S and the PCS Marketplace 315
Candidates for PCS Technologies 316
The Cellular Digital Data Packet System Specification (CDPD) 317
CDPD Services and Servers 319
Third-Generation Mobile Systems 321
Some Concluding Thoughts 321
Mobile Communications Systems Worksheet 322
Mobile Communications Summary 323
10. Residential Broadband 325
Introduction 325
The Problem with the Subscriber Loop 326
The Proposed Solutions: Two Interlocking Approaches, Coding/Modulation and Wiring 326
How Much Bandwidth Is Needed to Satisfy the Subscriber? 327
Downstream Bandwidth 328
Upstream Bandwidth 328
Beyond the Coding/Modulation and Wiring: Service Provisions 329
Switched Digital Video (SDV) 330
Coding and Modulation 330
HDSL 330
ADSL 331
Wiring at the Local Loop: Subscriber Loop Options 332
Hybrid/fiber Copper (HFCop) 332
Hybrid/fiber Coax (HFC) 334
Fiber to the Curb (FTTC) and Fiber to the Home (FTTH) 337
The Wireless Option 337
Managing the Broadband Signals 339
Bellcores TR-303 Specification 340
Residential Broadband Worksheet 340
Summary 340
Appendix 10A: Coding and Modulation Techniques for Residential Broadband 342
Introduction 342
Quadrature Amplitude Modulation (QAM) 342
Examples of Modulation Schemes and Bit Rates 347
Carrierless Amplitude/Phase Modulation (CAP) 347
11. Broadband Signaling Networks 349
Introduction 349
What Are Broadband Signaling Networks? 349
Differences between Broadband and Conventional Signaling Systems 350
N-ISDN and B-ISDN 351
Example of a Broadband Signaling Network Operation 351
Examples of Services Provided by the Broadband Network 354
ISO 9577 355
ATM Parameters 356
The Broadband Signaling Protocols 356
How the Broadband Signaling Stacks Operate 357
Broadband Signaling Worksheet 360
Summary 360
12. Advanced Intelligent Network 361
Introduction 361
Operator Services Systems (OSS) 361
The 800 ServiceInklings of an Advanced Intelligent Network (AIN) 362
Key Aspects of the AIN 364
The Intelligent Network and the Advanced Intelligent Network 364
Distribution of Functions 365
Evolution to the AIN 366
Other Parts of the AIN 367
Example of an AIN Operation 369
The AIN Basic Call Model 370
Standardized Messages 374
The Private Virtual Network 375
AIN Worksheet 377
Summary 378
13. Internet Protocol, Version 6 (Ipv6) 379
Introduction 379
Functions of the Internet Protocol (Ipv4) 379
The IP Address 381
Problems with IP and the IP Address 383
The Solutionan Expanded IP Address Space 383
Alternatives to the Overhead of IPv6 Addresses 384
The Next Generation IPIPv6 384
Functions of the IPv4 Header Fields 384
Functions of the IPv6 Header Fields 387
IPv6 and ATM 388
Fixed Routing and Virtual Circuits 388
Supporting Different Types of Traffic 389
The IPv6-ATM Debate 389
IPv6 Worksheet 390
Summary 390
Appendix A: A Tutorial on Communications Networks 393
Introduction 393
Data Communications Networks 393
Classifying Networks 393
Wide Area and Local Area Networks 394
Network Components 395
Voice Networks 398
Nonhierarchical Routing 400
History of and Inherent Problems with Coexistence of Analog and Digital Systems 400
Analog-to-Digital Conversion 401
Data Images over Voice Channels 404
FDM, TDM, and STDM 405
Circuit, Message, Packet, and Cell Switching 409
Network Routing Operations 411
The Challenge of Integrating Voice, Data, and Video Applications 414
Fast Packet Switching (FPS) 416
Hybrid Switching 417
Appendix B: Layered Protocols, OSI, and TCP/IP 419
Introduction 419
Protocols and the OSI Model 419
OSI Layer Operations 420
The Internet Protocols (TCP/IP) 426
The Internet Layers 428
IP Functions 430
TCP Operations 432
Appendix C: Management Information Bases (MIBs) 435
Introduction 435
Purpose of a MIB 435
Examples of MIB Objects and Other Entries 436
Appendix D: Emerging Communications Technologies Worksheet 438
Abbreviations 439
References 445