Network Working Group J. Rosenberg Request for Comments: 4575 Cisco Systems Category: Standards Track H. Schulzrinne Columbia University O. Levin, Ed. Microsoft Corporation August 2006 A Session Initiation Protocol (SIP) Event Package for Conference State 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 (2006). Abstract This document defines a conference event package for tightly coupled conferences using the Session Initiation Protocol (SIP) events framework, along with a data format used in notifications for this package. The conference package allows users to subscribe to a conference Uniform Resource Identifier (URI). Notifications are sent about changes in the membership of this conference and optionally about changes in the state of additional conference components. Rosenberg, et al. Standards Track [Page 1] RFC 4575 Conference Package August 2006 Table of Contents 1. Introduction ....................................................4 2. Terminology .....................................................4 3. Conference Event Package ........................................4 3.1. Event Package Name .........................................5 3.2. Filtering ..................................................5 3.3. Subscription Duration ......................................5 3.4. NOTIFY Bodies ..............................................5 3.5. Notifier Processing of SUBSCRIBE Requests ..................6 3.6. Notifier Generation of NOTIFY Requests .....................6 3.7. Subscriber Processing of NOTIFY Requests ...................6 3.8. Handling of Forked Requests ................................7 3.9. Rate of Notifications ......................................7 3.10. State Agents ..............................................7 4. Conference Document .............................................7 4.1. Format .....................................................7 4.2. Namespace ..................................................7 4.3. Versioning .................................................8 4.4. Partial Notifications Mechanism ............................8 4.5. Element Keys ...............................................9 4.6. Constructing Coherent State Procedure ......................9 5. Conference Data ................................................11 5.1. Overview ..................................................11 5.2. .........................................13 5.3. ..................................14 5.3.1. ........................................14 5.3.2. .....................................15 5.3.3. ...............................16 5.3.4. ..................................16 5.4. ...............................................17 5.4.1. .....................................17 5.4.2. .........................................17 5.4.3. .............................................17 5.5. ........................................17 5.5.1. .......................................17 5.5.2. ...........................................18 5.5.3. ...........................................18 5.6. and Its Sub-elements .......................18 5.6.1. .....................................19 5.6.2. ..................................19 5.6.3. ............................................19 5.6.4. ........................................19 5.6.5. ...................................19 5.6.6. .........................................20 5.7. ................................................20 5.7.1. .....................................20 5.7.2. .........................................21 Rosenberg, et al. Standards Track [Page 2] RFC 4575 Conference Package August 2006 5.7.3. ...........................................21 5.7.4. ...................................22 5.7.5. .....................................23 5.7.6. .............................23 5.7.7. ...............................23 5.7.8. ............................................24 5.7.9. ........................................24 5.8. ...................................................24 5.8.1. .....................................25 5.8.2. .............................................25 5.8.3.