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The SIP Supported Header

Document Type Expired Internet-Draft (sip WG)
Expired & archived
Authors Jonathan Rosenberg , Henning Schulzrinne
Last updated 2001-07-24
RFC stream Internet Engineering Task Force (IETF)
Intended RFC status Proposed Standard
Additional resources Mailing list discussion
Stream WG state WG Document
Document shepherd (None)
IESG IESG state Expired
Consensus boilerplate Unknown
Telechat date (None)
Responsible AD (None)
Send notices to (None)

This Internet-Draft is no longer active. A copy of the expired Internet-Draft is available in these formats:


The Session Initiation Protocol (SIP) provides a mechanism that allows a client to request that a particular protocol extension be used to process the request. The server declines the request if it does not support the extension. However, there is currently no way for a server to determine which extensions are supported by the client. Knowing about client-supported extensions allows the server to tailor its response accordingly. Furthermore, SIP does not define a way for a client to query a server about the extensions it supports. This document defines a SIP extension that allows clients to indicate, in a request, the set of extensions supported. We also define a mechanism that allows clients, through an OPTIONS request, to determine the extensions supported by a server.


Jonathan Rosenberg
Henning Schulzrinne

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)