信息服务将像空气一样无所不在，普适概念已不再遥不可及，技术整合正在加快这一进程。通信整合是计算整合的必须和关键所在。通信的体系结构正在发生转变。铜线网络正在被宽带以太网和无线传输技术取代，而同时SS7(Signaling System Number 7)正在被基于IP的信号协议如SIP和H.323等所取代。本专著集中讨论了这一转变。它言简意赅地介绍了IP电话和公用电话网，深入探讨了如何在服务层协调这些网络。在不久的将来无论IP电话被何种新技术所取代，本专著提供的方法都可以用以确保下一轮通信与计算的融合得以顺利进行。

本书全面介绍了新兴的面向服务的电子通信体系。信息技术的高速发展使已往的高难计算逐渐变成越来越普及的电子服务，Web服务已日益盛行，传统的电信服务也越来越多地通过因特网来提供。本书介绍了面向服务的软件体系结构的最新发展，提供在因特网终端获取电信网服务的基本技术，并展示了将现有的电信服务全面Web化的最新研究成果。作者以网络电话作为Web服务的一个特例来讨论新技术的发展和日渐统一的因特网和电信网。

Foreword

The Authors

Acknowledgements

List of Abbreviations and Symbols

1 Introduction

 1．1 The Evolution ofInternet Telephony

 1．2 Problem Statement

 1．3 Solutions

1．3．1 The First Stage：Accessing Native PSTN Services from Intemet Telephony Endpoints

1．3．2 The Second Stage：PSTN Events as a Precursor for Internet Services

1．3．3 The Third Stage：Pervasive Computing and Telecommunication Services

2 Internet Telephony：The Evolution to a Service-Oriented Architecture

 2．1 Introduction

 2．2 Service Architecture for Traditional Telephone Network

 2．3 Intemet Services Architecture

 2．4 Requirements ofa Telecommunications SOA

 2．5 Conclusion

3 Background：Providing Telephony Service

 3．1 Service Architecture for the Wireline Public Switched Telephone Network

3．1．1 General Architecture ofthe PSTN

3．1．2 The IntelligentNetwork

3．1．3 The IN Conceptual Model

3．1．4 Physical Entities in an IN-EnabledNetwork

3．1．5 The Basic Call State Machine，Points in Call and Detection Points

3．1．6 The IN Capability Sets

3．1．7 Originating BCSM(O_BCSM)

3．1．8 Terminating BCSM(T_BCSM)

 3．2 Service Architecture for the Cellular Public Switched Telephone Network

3．2．1 Physical Entities in WIN

3．2．2 WIN PICs and DPs

 3．3 Service Architecture for Internet Telephony

3．3．1 Service Specification in Internet Telephony

3．3．2 Service Residency in Intemet Telephony

4 Comparative Analysis of Signaling Protocols

 4．1 Desirable Properties of a Candidate Protocol

4．1．1 Widespread Acceptance

4．1．2 Protoc01 Expressiveness

4．1．3 Protocol Extensibility

4．1．4 Primitives for Capability Description and Negotiation

4．1．5 Transaction-Style Message Exchanges

4．1．6 Suppot for an Event-Based Communications Model

4．1．7 Suppot for a Flexible Naming Scheme

 4．2 Protocols Evaluated

4．2．1 BICC

4．2．2 H.323

4．2．3 SIP

 4．3 Comparative Analysis

 4．4 The Novel SIP-Based Approach

5 Crossover Services Originating on the Internet

 5．1 Introduction

 5．2 Motivation

5．2．1 Rewrite Services for Intemet Telephony

5．2．2 Using a Platform．Neutral Service Creation and Execution Environment

5．2．3 Exploring New Techniques to Reuse Existing Services

 5．3 Call Model Mapping with State Sharing

5．3．1 CMM/SS：Preliminaries

5．3．2 CMM/SS：The Technique and Algorithms

5．3．3 CMM/SS：State Sharing and Global State

5．3．4 CMM/SS：Issues

 5．4 Implementing CMM/SS

5．4．1 CMM/SS Considerations

5．4．2 CMM/SS Architectural Model

5．4．3 Realizing CMM/SS in Software

5．4．4 Applying the Mapping

 5．5 Results from CMM/SS

5．5．1 Network Topology

5．5．2 Results

5．5．3 Service Description and Call Flows

 5．6 Performance ofCMM/SS

 5．7 CMM/SS：A General Solution

 5．8 Limitations of CMM/SS

 5．9 Related Work

 5．10 Conclusion

6 Crossover Services Originating on the Public Switched Telephone Network

 6．1 Introduction

6．1．1 Motivation

6．1．2 Genealogy and Relation to Standards Activities

6．1．3 Contributions

 6．2 Architecture for PSTN-Originated Crossover Services

 6．3 Research Challenges

6．3．1 Choosing Target Events

6．3．2 Modeling PSTN-Originated Crossover Services as a Wide-Area Event Notification Service

6．3．3 Representing the Events

6．3．4 Choosing a Protocol

6．3．5 Aggregating Events Before Publication

6．3．6 Scalability ofthe EM

6．3．7 Privacy，Security，and Trust

 6．4 An XML Schema to Represent Events in the PSTN

6．4．1 The<spirits-event>Element

6．4．2 The<Event>Element

 6．5 Proposed Extensions to SIP

6．5．1 The Asynchronous Event Notification Framework in SIP

6．5．2 The Extensions

 6．6 Examples

6．6．1 Notification ofMissed Calls

6．6．2 Presence for a Principal Using a Wireline PSTN Endpoint

6．6．3 Presence for a Principal Using a Cellular PSTN EndDoint

6．6．4 Helping First Responders

6．6．5 Schema Extension：Notifications for Low Pre-Paid Card Balance

 6．7 A Taxonomy of PSTN-Originated Crossover Services

 6．8 SIP：The Distributed Middleware

 6．9 Related Work

 6．10 Conclusion

7 Smart Spaces in the Telecommunications Domain

 7．1 Introduction

 7．2 Research Thrusts ofPervasive Computing

7．2．1 Effective Use of Smart Spaces

7．2．2 Invisibility

7．2．3 Localized Scalability

7．2．4 Masking Uneven Conditions

 7．3 Implementing a Telecommunications Smart Space

7．3．1 The Main Actors

7．3．2 Authentication and Encryption

7．3．3 Policies

7．3．4 Constructing a Telecommunications Smart Space

 7．4 Design and Implementation ofthe Event Manager

7．4．1 Design ofthe EM

 7．5 Performance Analysis ofthe Event Manager

7．5．1 Assumptions and Realffies

7．5．2 Determining Service Time per Event

7．5．3 Calculating Blocking Probability：Erlang-B Analysis

7．5．4 Modeling the Event Manager as an M/D/1 Queue

 7．6 Related Work

 7．7 Conclusion

8 Conclusions

Appendix A The SPIRITS(Services in PSTN Requesting Internet Services)Protocol

Appendix B Interworking SIP and Intelligent Network Applications

Appendix C XML Schema for PSTN Events

Appendix D XML Schema for SMS to IM

Appendix E Raw Data for Event Manager Performance Analysis

Bibliography