The 3G IP Multimedia Subsystem (IMS): Merging the Internet and the Cellular Worlds

The 3G IP Multimedia Subsystem (IMS)......Page 3
Contents......Page 9
Foreword by Stephen Hayes......Page 17
Foreword by Allison Mankin and Jon Peterson......Page 19
About the Authors......Page 21
Preface......Page 23
Acknowledgements......Page 25
I Introduction to the IMS......Page 27
1.1 The Internet......Page 31
1.3 Why Do We Need the IMS?......Page 32
1.4 Relation between IMS and non-IMS Services......Page 34
2.1 Relations between IMS-related Standardization Bodies......Page 37
2.2.1 Structure of IETF......Page 38
2.2.2 Working Group Operations......Page 39
2.2.3 Types of RFCs......Page 40
2.3 Third Generation Partnership Project (3GPP)......Page 41
2.3.1 3GPP Structure......Page 42
2.3.2 3GPP Deliverables......Page 43
2.4.2 3GPP2 Deliverables......Page 44
2.5 IETF-3GPP/3GPP2 Collaboration......Page 45
2.5.2 Operations and Management Area......Page 46
2.5.3 Transport Area......Page 47
3.1.1 GSM Circuit-switched......Page 49
3.2 IMS Requirements......Page 50
3.2.1 IP Multimedia Sessions......Page 51
3.2.5 Service Control......Page 52
3.3 Overview of Protocols Used in the IMS......Page 53
3.3.1 Session Control Protocol......Page 54
3.4 Overview of IMS Architecture......Page 55
3.4.2 The CSCF......Page 57
3.4.3 The AS......Page 60
3.4.6 The PSTN/CS Gateway......Page 62
3.4.7 Home and Visited Networks......Page 63
3.5 Identification in the IMS......Page 65
3.5.2 Private User Identities......Page 66
3.5.3 The Relation between Public and Private User Identities......Page 67
3.6 SIM, USIM, and ISIM in 3GPP......Page 68
3.6.2 USIM......Page 69
3.6.3 ISIM......Page 70
II The Signaling Plane in the IMS......Page 73
4.1.1 Session Descriptions and SDP......Page 77
4.1.2 The Offer/Answer Model......Page 79
4.1.4 User Location......Page 80
4.2 SIP Entities......Page 81
4.2.1 Forking Proxies......Page 84
4.3 Message Format......Page 85
4.5 The Start Line in SIP Requests: the Request Line......Page 86
4.6 Header Fields......Page 88
4.8 SIP Transactions......Page 89
4.9 Message Flow for Session Establishment......Page 92
4.10.1 Record-Route, Route, and Contact Header Fields......Page 97
4.11 Extending SIP......Page 98
4.12 Caller Preferences and User Agent Capabilities......Page 99
4.13 Reliability of Provisional Responses......Page 101
4.14 Preconditions......Page 103
4.15.1 High Notification Rates......Page 106
4.16 Signaling Compression......Page 108
4.16.2 Static SIP/SDP Dictionary......Page 109
4.17 Content Indirection......Page 110
4.18 URI Lists......Page 113
5 Session Control in the IMS......Page 117
5.1 Prerequisites for Operation in the IMS......Page 118
5.2 IP Connectivity Access Network......Page 119
5.3 P-CSCF Discovery......Page 120
5.4 IMS-level Registration......Page 122
5.4.1 IMS Registration with an ISIM......Page 123
5.4.2 IMS registration with a USIM......Page 131
5.5 Subscription to the reg Event State......Page 136
5.6 Basic Session Setup......Page 141
5.7 Application Servers: Providing Services to Users......Page 172
5.7.1 Generalities About Application Servers......Page 174
5.7.2 Types of Application Servers......Page 176
5.7.3 The Session Setup Model through Application Servers......Page 179
5.7.4 Filter Criteria......Page 187
5.7.5 An Example of Service Execution......Page 191
5.8.1 SIP-PSTN Interworking......Page 195
5.8.2 Interworking with Non-IMS SIP-based Networks......Page 198
5.9 Emergency Sessions......Page 202
6.1 Authentication, Authorization, and Accounting......Page 205
6.2 AAA Framework on the Internet......Page 206
6.3 The Diameter Protocol......Page 207
6.3.1 Diameter Sessions......Page 208
6.3.2 The Format of a Diameter Message......Page 209
6.3.3 Attribute Value Pairs......Page 210
6.3.5 Diameter Base Protocol Commands......Page 212
6.3.6 Diameter Base Protocol AVPs......Page 214
7.2 The Cx and Dx Interfaces......Page 217
7.2.1 Command Codes Defined in the Diameter Application for the Cx Interface......Page 219
7.2.2 AVPs Defined in the Diameter Application for the Cx Interface......Page 224
7.3 The Sh Interface......Page 227
7.3.1 Command Codes Defined in the Diameter Application for the Sh interface......Page 229
7.3.2 AVPs Defined in the Diameter Application for the Sh Interface......Page 231
7.4 Accounting......Page 232
7.5 Charging Architecture......Page 233
7.6 Offline Charging......Page 234
7.6.1 IMS Terminal in a Visited Network......Page 235
7.6.2 IMS Terminal in Its Home Network......Page 237
7.6.3 The Rf Interface......Page 240
7.7.1 S-CSCF......Page 241
7.7.2 Application Servers and the MRFC......Page 242
8.1 HTTP Digest......Page 247
8.1.1 Security Properties of Digest......Page 249
8.3 TLS......Page 250
8.4 S/MIME......Page 252
8.4.1 Self-signed Certificates......Page 255
8.6 IPsec......Page 257
8.6.1 ESP and AH......Page 259
8.6.3 Internet Key Exchange......Page 260
8.8 Encrypting Media Streams......Page 262
8.8.1 MIKEY......Page 263
9.1.1 Authentication and Authorization......Page 265
9.1.2 Authentication and Authorization with ISIM......Page 266
9.1.4 Security Association Establishment......Page 269
9.2 Network Security......Page 271
10.1 The COPS Protocol......Page 273
10.2 The Outsourcing Model......Page 275
10.3 The Configuration Model......Page 276
11.1 SIP Procedures......Page 279
11.2 Media Authorization......Page 280
11.2.2 Media Authorization Token......Page 281
11.4 Initialization Procedure......Page 284
12.1 Integrated Services......Page 285
12.1.1 RSVP......Page 286
12.2 Differentiated Services......Page 287
13.1 Instructions to Perform Resource Reservations......Page 289
13.1.1 Proxy Modifying Bodies......Page 290
13.3 Network Authorization......Page 292
13.4 QoS in the Network......Page 294
III The Media Plane in the IMS......Page 295
14.1 Speech Encoding......Page 299
14.1.1 Pulse Code Modulation......Page 300
14.1.2 Linear Prediction......Page 301
14.1.3 GSM-FR......Page 303
14.1.4 AMR......Page 304
14.1.5 AMR-WB......Page 307
14.1.6 SMV......Page 311
14.2 Video Encoding......Page 312
14.2.2 H.263......Page 313
14.2.3 Image Encoding......Page 314
14.4 Mandatory Codecs in the IMS......Page 315
15.1 Reliable Media Transport......Page 317
15.2 Unreliable Media Transport......Page 318
15.2.2 RTP......Page 319
15.2.3 RTCP......Page 321
15.3 Media Transport in the IMS......Page 323
IV Building Services with the IMS......Page 325
16.1 Overview of the Presence Service......Page 329
16.2 Presence Information Data Format......Page 331
16.3 Rich Presence Information Data Format......Page 332
16.5 Timed Presence Extension to the PIDF......Page 334
16.7 Presence Publication......Page 337
16.9 Watcher Information......Page 339
16.10 SIP Exploders and Resource Lists......Page 342
16.11 XML Configuration Access Protocol......Page 344
16.11.1 XCAP Application Usage......Page 345
16.12 Presence Optimizations......Page 346
16.12.2 Event Notification Filtering......Page 347
17.1 The Foundation of Services......Page 349
17.2 Presence Architecture in the IMS......Page 350
17.3 Watcher Subscription......Page 351
17.4 Subscription to Watcher Information......Page 352
17.5 Presence Publication......Page 353
17.7 The Ut Interface......Page 354
18 Instant Messaging on the Internet......Page 357
18.2 Pager-mode Instant Messaging......Page 358
18.2.1 Congestion Control with MESSAGE......Page 359
18.3.2 A Closer Look at MSRP......Page 360
19.1 Pager-mode Instant Messaging in the IMS......Page 365
19.2 Session-based Instant Messaging in the IMS......Page 366
20.1 Push-To-Talk Standardization......Page 371
20.2 Architecture......Page 372
20.3 Interoperator Sessions......Page 374
A.2 The Multimedia Domain (MMD)......Page 375
A.3 Architecture of the 3GPP2 IMS......Page 376
B.2 3GPP Specifications......Page 379
B.3 3GPP2 Specifications......Page 380
Bibliography......Page 385
Index......Page 399