Session Initiation Protocol demystified

State-of-the-art SIP primer SIP (Session Initiation Protocol) is the open standard that will make IP telephony an irresistible force in communications, doing for converged services what http does for the Web. SIP Demystified – authored by Gonzalo Camarillo, one of the contributors to SIP development in the IETF—gives you the tools to keep your company and career competitive. This guide tells you why the standard is needed, what architectures it supports, and how it interacts with other protocols. As a bonus, you even get a context-setting background in data networking. Perfect if you’re moving from switched voice into a data networking environment, here’s everything you need to understand: * Where, why, and how SIP is used * What SIP can do and deliver * SIP’s fit with other standards and systems * How to plan implementations of SIP-enabled services * How to size up and choose from available SIP products SIP Demystified SIP Demystified 1 Copyright 5 Acknowledgments 9 Contents 10 Preface 14 Foreword 18 Ch1 Signalling in the Circuit-Switched Network 20 The Origins of Circuit-Switching 22 Characteristics of Circuit-Switching 25 Strengths of Circuit-Switching 25 Weaknesses of Circuit-Switching 26 Introduction to Signalling 27 FDM and In-band Signalling 30 Analog Transmission 31 Digital Transmission 32 Time Division Multiplexing 34 Digital Signalling Systems 35 Access Signalling 37 Trunk Signalling 38 SS7 42 The Paradigm Behind SS7 44 Conclusions 47 Ch2 Packet Switching, IP, and the IETF 48 Packet Switching 49 Strengths of Packet Switching 54 Weaknesses of Packet Switching 55 X.25 55 IP and the Internet Paradigm 56 IP Connectivity 56 Intelligence Pushed to the End Systems 57 End-to-End Protocols 60 General Design Issues 61 History of the Internet Protocol Development Process 64 Origins of the Request For Comments 64 Coordination Bodies 65 The IETF 67 The IESG 68 The Technical Work 68 IETF Specifications: RFCs and I-Ds 69 Ch3 The Internet Multimedia Conferencing Architecture 74 The Internet Layered Architecture 75 Transport Layer Protocols 76 Real-Time Services in the Internet 78 Multicast 81 Routing Towards Many Receivers 81 Advantages of Multicast 83 Multicast Routing Protocols 84 IGMP 87 The Mbone 89 Transport of Real-Time Data: RTP 89 Jitter and Sequencing of Datagrams 90 Real-Time Transport Control Protocol 92 QoS Provisioning: Integrated Services and Differentiated Services 93 Integrated Services 93 Differentiated Services (DiffServ) 98 Session Announcement Protocol (SAP) 100 Session Descriptions 101 Session Description Protocol (SDP) 101 SDP Syntax 102 SDP Next Generation (SDPng) 105 Real-Time Streaming Protocol (RTSP) 106 Usage Example of the Internet Multimedia Conferencing Toolkit 106 Ch4 The Session Initiation Protocol: SIP 108 SIP History 109 Session Invitation Protocol: SIPv1 110 Simple Conference Invitation Protocol: SCIP 111 Session Initiation Protocol: SIPv2 111 Functionality Provided by SIP 113 Session Establishment, Modification, and Termination 113 User Mobility 115 SIP Entities 117 User Agents 117 Redirect Servers 121 Proxy Servers 122 Registrars 124 Location Servers 124 Good Features of SIP 125 SIP Is Part of the IETF Toolkit 125 Separation Between Establishing and Describing a Session 127 Intelligence in the End System: End-to-End Protocol 128 Interoperability 128 Scalability 129 SIP as a Platform for Service Creation 129 Ch5 SIP: Protocol Operation 134 Client/Server Transactions 135 SIP Responses 135 SIP Requests 136 INVITE 138 ACK 140 CANCEL 142 BYE 144 REGISTER 144 OPTIONS 145 Types of Proxy Servers 145 Call Stateful Proxy 146 Stateful Proxy 146 Stateless Proxy 148 Distribution of Proxies 148 Format of SIP Messages 149 SIP Request Format 151 SIP Response Format 151 SIP Headers 153 SIP Bodies 161 Transport Layer 163 INVITE Transactions 163 CANCEL Transactions 167 Other Transactions 169 Detailed Example 170 SIP Call Through a Proxy 170 Ch6 Extending SIP: The SIP Toolkit 178 Extension Negotiation 179 How It’s Done 180 Design Principles for SIP Extensions 181 Do Not Break the Toolkit Approach 182 Peer-to-Peer Relationship 182 Independence from Session Type 183 Do Not Change Method Semantics 183 Extensions to SIP 184 The SIP Toolkit 184 Reliable Delivery of Provisional Responses 184 Mid-session Transactions That Do Not Change the State of the Session 188 Multiple Message Bodies 189 Instant Messages 190 Automatic Configuration of UAs 191 Preconditions to Be Fulfilled Before Alerting 193 Caller Preferences 195 Asynchronous Notification of Events 198 Third-party Call Control 200 Session Transfer 203 Sending Commands 205 SIP Security 206 Ch7 Building Applications with the SIP Toolkit 210 Third-generation Mobile Systems 211 Network Domains 212 Call Flow Examples 214 Instant Messages and Presence 218 SIMPLE Working Group 218 Presence Architecture 219 Instant Messaging 220 PacketCable 221 Architecture 222 Call Flow Example 222 PSTN-to-SIP Interworking 223 Low-Capacity Gateways 226 High-Capacity Gateways 228 SIP Extensions for PSTN Interworking 229 The PINT Service Protocol 232 SIP for Conferencing 233 Multicast Conferences 234 End User Mixing Model 234 Multipoint Control Unit (MCU) 235 Decentralized Multipoint Conference 236 Control of Networked Appliances 238 Appendix 240 IETF Web site 240 Henning Schulzrinne’s SIP Web page 242 Dean Willis' Web Pages 244 The SIP forum 245 RFC example 246 RFC 248 Acronyms 258 References 264 Index 270 About The Author 284 SIP,VoIP Publisher's Products purchased from Third Party sellers are not guaranteed by the publisher for quality, authenticity, or access to any online entitlements included with the product. State-of-the-art SIP primer SIP (Session Initiation Protocol) is the open standard that will make IP telephony an irresistible force in communications, doing for converged services what http does for the Web. SIP Demystified authored by Gonzalo Camarillo, one of the contributors to SIP development in the IETFgives you the tools to keep your company and career competitive. This guide tells you why the standard is needed, what architectures it supports, and how it interacts with other protocols. As a bonus, you even get a context-setting background in data networking. Perfect if youre moving from switched voice into a data networking environment, heres everything you need to * Where, why, and how SIP is used * What SIP can do and deliver * SIPs fit with other standards and systems * How to plan implementations of SIP-enabled services * How to size up and choose from available SIP products Annotation State-of-the-art SIP primerSIP (Session Initiation Protocol) is the open standard that will make IP telephony an irresistible force in communications, doing for converged services what http does for the Web. SIP Demystified Đ#8211; authored by Gonzalo Camarillo, one of the contributors to SIP development in the IETFĐ#8212;gives you the tools to keep your company and career competitive. This guide tells you why the standard is needed, what architectures it supports, and how it interacts with other protocols. As a bonus, you even get a context-setting background in data networking. Perfect if youĐ#8217;re moving from switched voice into a data networking environment, hereĐ#8217;s everything you need to understand: * Where, why, and how SIP is used * What SIP can do and deliver * SIPĐ#8217;s fit with other standards and systems * How to plan implementations of SIP-enabled services * How to size up and choose from available SIP products Content: Chapter 1: Signaling in the Circuit-Switched Network. Chapter 2: Packet Switching, IP, and the IETF. Chapter 3: The Internet Multimedia Conferencing Architecture. Chapter 4: The Session Initiation Protocol: SIP. Chapter 5: SIP: Protocol Operation. Chapter 6: Extending SIP: The SIP Toolkit. Chapter 7: Building Applications with the SIP Toolkit. Appendix RFC Acronyms References Index Session Initiation Protocol is essentially a simple protocol, but understanding why it's needed, what architectures it supports, and how it interacts with other protocols is key to deploying it. This work contextualises SIP against its forebears and competitors This book gives you jargon-free explanations of the concepts that set SIP apart from other protocols and the reasons the standard was drafted--so you can decide what to do with it. -- Edited summary from book The telephone network, also known as the Public Switched Telephone Network (PSTN), reaches almost every country in the world.