An Extension to the Session Initiation Protocol (SIP) for Request History Information
RFC 4244
Document | Type |
RFC - Proposed Standard
(November 2005; Errata)
Obsoleted by RFC 7044
|
|
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Last updated | 2015-10-14 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized with errata bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 4244 (Proposed Standard) | |
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Allison Mankin | ||
Send notices to | rohan@ekabal.com |
Network Working Group M. Barnes, Ed. Request for Comments: 4244 Nortel Category: Standards Track November 2005 An Extension to the Session Initiation Protocol (SIP) for Request History Information Status of This Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2005). Abstract This document defines a standard mechanism for capturing the history information associated with a Session Initiation Protocol (SIP) request. This capability enables many enhanced services by providing the information as to how and why a call arrives at a specific application or user. This document defines a new optional SIP header, History-Info, for capturing the history information in requests. Table of Contents 1. Introduction ....................................................2 1.1. Overview ...................................................2 1.2. Conventions Used in This Document ..........................3 1.3. Background: Why define a Generic "Request History" capability? ................................................3 2. "Request History" Requirements ..................................4 2.1. Security Requirements ......................................6 2.2. Privacy Requirements .......................................7 3. Request History Information Description .........................7 3.1. Optionality of History-Info ................................8 3.2. Securing History-Info ......................................8 3.3. Ensuring the Privacy of History-Info .......................9 4. Request History Information Protocol Details ....................9 4.1. Protocol Structure of History-Info ........................10 4.2. Protocol Examples .........................................11 4.3. Protocol Usage ............................................12 Barnes Standards Track [Page 1] RFC 4244 SIP Request History Information November 2005 4.3.1. User Agent Client (UAC) Behavior ...................12 4.3.2. User Agent Server (UAS) Behavior ...................13 4.3.3. Proxy Behavior .....................................13 4.3.4. Redirect Server Behavior ...........................18 4.4. Security for History-Info .................................18 4.5. Example Applications Using History-Info ...................19 4.5.1. Example with Privacy Header for Entire Request at Proxy2 ..................................21 4.5.2. Example with Privacy Header for Specific URI (UA4) at Proxy2 ................................22 5. Application Considerations .....................................24 6. Security Considerations ........................................25 7. IANA Considerations ............................................25 7.1. Registration of New SIP History-Info Header ...............25 7.2. Registration of "history" for SIP Privacy Header ..........26 8. Normative References ...........................................26 9. Informative References .........................................26 10. Acknowledgements ..............................................26 11. Contributors' Addresses .......................................27 Appendix. Example Scenarios........................................28 Appendix A. Sequentially forking (History-Info in Response).....28 Appendix B. Voicemail...........................................34 Appendix C. Automatic Call Distribution Example.................39 Appendix D. Session via Redirect and Proxy Servers..............41 1. Introduction 1.1. Overview Many services that SIP is anticipated to support require the ability to determine why and how the call arrived at a specific application. Examples of such services include (but are not limited to) sessions initiated to call centers via "click to talk" SIP Uniform Resource Locators (URLs) on a web page, "call history/logging" style services within intelligent "call management" software for SIP User Agents (UAs), and calls to voicemail servers. Although SIP implicitly provides the redirect/retarget capabilities that enable calls to be routed to chosen applications, there is currently no standard mechanism within SIP for communicating the history of such a request.Show full document text