Session Initiation Protocol (SIP)-Specific Event Notification
RFC 3265

Network Working Group                                        A. B. Roach
Request for Comments: 3265                                   dynamicsoft
Updates: 2543                                                  June 2002
Category: Standards Track

     Session Initiation Protocol (SIP)-Specific Event Notification

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 (2002).  All Rights Reserved.

Abstract

   This document describes an extension to the Session Initiation
   Protocol (SIP).  The purpose of this extension is to provide an
   extensible framework by which SIP nodes can request notification from
   remote nodes indicating that certain events have occurred.

   Concrete uses of the mechanism described in this document may be
   standardized in the future.

   Note that the event notification mechanisms defined herein are NOT
   intended to be a general-purpose infrastructure for all classes of
   event subscription and notification.

Table of Contents

   1.       Introduction...........................................  3
   1.1.     Overview of Operation..................................  4
   1.2.     Documentation Conventions..............................  4
   2.       Definitions............................................  5
   3.       Node Behavior..........................................  6
   3.1.     Description of SUBSCRIBE Behavior......................  6
   3.1.1.   Subscription Duration..................................  6
   3.1.2.   Identification of Subscribed Events and Event Classes..  6
   3.1.3.   Additional SUBSCRIBE Header Values.....................  7
   3.1.4.   Subscriber SUBSCRIBE Behavior..........................  7
   3.1.5.   Proxy SUBSCRIBE Behavior...............................  9
   3.1.6.   Notifier SUBSCRIBE Behavior............................ 10

Roach                       Standards Track                     [Page 1]
RFC 3265            SIP-Specific Event Notification            June 2002

   3.2.     Description of NOTIFY Behavior......................... 13
   3.2.1.   Identification of Reported Events, Event Classes, and
            Current State.......................................... 13
   3.2.2.   Notifier NOTIFY Behavior............................... 14
   3.2.3.   Proxy NOTIFY Behavior.................................. 15
   3.2.4.   Subscriber NOTIFY Behavior............................. 16
   3.3.     General................................................ 18
   3.3.1.   Detecting support for SUBSCRIBE and NOTIFY............. 18
   3.3.2.   CANCEL requests........................................ 18
   3.3.3.   Forking................................................ 18
   3.3.4.   Dialog creation and termination........................ 18
   3.3.5.   State Agents and Notifier Migration.................... 19
   3.3.6.   Polling Resource State................................. 20
   3.3.7.   Allow-Events header usage.............................. 21
   3.3.8.   PINT Compatibility..................................... 21
   4.       Event Packages......................................... 21
   4.1.     Appropriateness of Usage............................... 21
   4.2.     Event Template-packages................................ 22
   4.3.     Amount of State to be Conveyed......................... 22
   4.3.1.   Complete State Information............................. 23
   4.3.2.   State Deltas........................................... 23
   4.4.     Event Package Responsibilities......................... 24
   4.4.1.   Event Package Name..................................... 24
   4.4.2.   Event Package Parameters............................... 24
   4.4.3.   SUBSCRIBE Bodies....................................... 24
   4.4.4.   Subscription Duration.................................. 25
   4.4.5.   NOTIFY Bodies.......................................... 25
   4.4.6.   Notifier processing of SUBSCRIBE requests.............. 25
   4.4.7.   Notifier generation of NOTIFY requests................. 25
   4.4.8.   Subscriber processing of NOTIFY requests............... 26
   4.4.9.   Handling of forked requests............................ 26
   4.4.10.  Rate of notifications.................................. 26
   4.4.11.  State Agents........................................... 27
   4.4.12.  Examples............................................... 27
   4.4.13.  Use of URIs to Retrieve State.......................... 27
   5.       Security Considerations................................ 28