We have telephony to talk to each other, messaging to dispatch mail or instant messages, browsing to read published content and search engines to locate content sites. However, current mobile networks do not provide the possibility for one application rich terminal to communicate with another in a peer-to-peer session beyond voice calls. Mobile telephony with the current technology has been hugely successful and shows that there is immense value in communicating with peers while being mobile, and with increasingly available smarter multimedia terminals the communication experience will be something more than just exchanging voice. Those multimedia terminals need IP multimedia networks. Hence, the Third Generation Partnership Project (3GPP) has developed a standard for SIP based IP multimedia service machinery known as 'The IMS (IP Multimedia Subsystem)' and this informative book explains everything you need to know about it……... Presents the architecture and functionality of logical elements of IMS and their interfaces providing detailed description of how elements are connected, what protocols are used and how they are used Explains how the optimisation and security of the mobile communication environment has been designed in the form of user authentication and authorisation based on mobile identities Illustrates how optimisation at the radio interface is achieved using specific rules at the user to network interface. This includes signalling compression mechanisms as well as security and policy control mechanisms, allowing radio loss and recovery detection Addresses important aspects from an operator's point of view while developing architecture such as charging framework, policy and service control Describes many services on top of IMS in detail, including voice, presence, messaging and conferencing. Written in a manner that allows readers to choose the level of knowledge and understanding they need to gain about the IMS, this volume will have instant appeal to a wide audience ranging from marketing managers, research and development engineers, network engineers, developers, test engineers to university students.
Author(s): Miikka Poikselka
Year: 2004
Language: English
Pages: 448
Contents......Page 8
Foreword......Page 20
Preface......Page 22
Acknowledgements......Page 24
List of Figures......Page 26
List of Tables......Page 30
PART I: ARCHITECTURE......Page 32
1.1 Why the Internet Protocol Multimedia Subsystem was developed......Page 34
1.2 Where did it come from?......Page 36
1.3 Other relevant standardization bodies......Page 39
2.1 Architectural requirements......Page 42
2.2 Description of IMS-related entities and functionalities......Page 49
2.3 IMS reference points......Page 60
3.2 Registration......Page 80
3.3 Session initiation......Page 82
3.4 Identification......Page 84
3.5 Identity modules......Page 90
3.6 Security services in the IMS......Page 91
3.7 Discovering the IMS entry point......Page 103
3.8 S-CSCF assignment......Page 104
3.9 Mechanism for controlling bearer traffic......Page 106
3.10 Charging......Page 122
3.11 User profile......Page 132
3.12 Service provision......Page 136
3.13 Connectivity between traditional Circuit-Switched users and IMS users......Page 140
3.14 Mechanism to register multiple user identities at once......Page 142
3.15 Sharing a single user identity between multiple terminals......Page 144
3.16 SIP compression......Page 145
PART II: DETAILED PROCEDURES......Page 148
4.1 The example scenario......Page 150
4.2 Base standards......Page 152
5.1 Overview......Page 154
5.2 Signalling PDP context establishment......Page 156
5.5 SIP registration and registration routing aspects......Page 157
5.6 Authentication......Page 168
5.7 Access security—IPsec SAs......Page 174
5.8 SIP Security Mechanism Agreement......Page 186
5.9 Compression negotiation......Page 193
5.10 Access and location information......Page 196
5.12 User identities......Page 198
5.13 Re-registration and re-authentication......Page 212
5.14 De-registration......Page 215
6.1 Overview......Page 222
6.2 Caller and callee identities......Page 223
6.3 Routing......Page 229
6.4 Compression negotiation......Page 247
6.5 Media negotiation......Page 250
6.6 Resource reservation......Page 260
6.7 Controlling the media......Page 270
6.8 Charging-related information for sessions......Page 276
6.9 Release of a session......Page 281
7.2 Scenario 2: routing from a PSI to a user......Page 286
7.3 Scenario 3: routing from a PSI to another PSI......Page 287
PART III: PROTOCOLS......Page 290
8.1 Background......Page 292
8.2 Design principles......Page 293
8.3 SIP architecture......Page 294
8.4 Message format......Page 296
8.5 The SIP URI......Page 299
8.6 The tel URI......Page 300
8.7 SIP structure......Page 301
8.8 Registration......Page 304
8.9 Dialogs......Page 305
8.10 Sessions......Page 307
8.11 Security......Page 309
8.12 Routing requests and responses......Page 314
8.13 SIP extensions......Page 318
9.1 SDP message contents......Page 332
9.3 Selected SDP lines......Page 334
10.2 The answer......Page 338
10.3 Offer/Answer processing......Page 339
11.1 RTP for real-time data delivery......Page 342
11.2 RTCP......Page 344
11.4 RTP profile and payload format specification for audio and video (RTP/AVP)......Page 345
12.2 The naming authority pointer (NAPTR) DNS RR......Page 348
12.3 ENUM – the E.I64 to URI Dynamic Delegation Discovery System (DDD) application......Page 350
12.4 Service records (SRVs)......Page 352
13.2 Packet Data Protocol (PDP)......Page 354
13.3 Access points......Page 355
13.4 PDP context types......Page 356
14.2 TLS Record Protocol......Page 358
14.3 TLS Handshake Protocol......Page 359
14.4 Summary......Page 361
15.1 Introduction......Page 362
15.3 Message processing......Page 363
15.5 Diameter agents......Page 365
15.6 Message structure......Page 366
15.7 Error handling......Page 368
15.8 Diameter services......Page 369
15.9 Specific Diameter applications used in 3GPP......Page 370
15.11 Diameter credit control application......Page 371
15.12 Summary......Page 374
16.2 Connection model......Page 376
16.3 Protocol operation......Page 377
17.1 Introduction......Page 380
17.2 Message structure......Page 381
17.3 COPS usage for policy provisioning (COPS-PR)......Page 382
17.5 Summary......Page 385
18.1 Introduction......Page 386
18.3 Internet Security Association and Key Management Protocol (ISAKMP)......Page 387
18.5 Encapsulated Security Payload (ESP)......Page 388
18.6 Summary......Page 390
19.1 SigComp architecture......Page 392
19.2 Compartments......Page 393
19.3 Compressing a SIP message in IMS......Page 394
20 DHCPv6......Page 396
20.2 DHCP options for SIP servers......Page 397
21.1 XCAP application usage......Page 400
22 CPCP......Page 402
PART IV: SERVICES......Page 404
23 Presence......Page 406
23.1 SIP for presence......Page 407
23.2 Presence service architecture in IMS......Page 408
23.4 XCAP usage for resource (presentity) lists......Page 409
23.7 Watcher information event template package......Page 410
23.8 Example signalling flows of presence service operation......Page 411
24.1 Overview of IMS messaging......Page 414
24.3 Immediate messaging......Page 415
24.5 Deferred delivery messaging......Page 416
25.1 Conferencing architecture......Page 418
25.2 SIP event package for conference state......Page 419
25.3 Example signalling flows of conferencing service operation......Page 420
References......Page 424
Abbreviations......Page 432
B......Page 440
D......Page 441
H......Page 442
I......Page 443
M......Page 444
P......Page 445
R......Page 446
S......Page 447
T......Page 449
X......Page 450
