SIP 183 Session Progress Message

Document Type Expired Internet-Draft (sip WG)
Authors Jonathan Rosenberg  , Henning Schulzrinne  , Matthew Cannon  , Steve Donovan  , Adam Roach 
Last updated 1999-10-22
Stream Internet Engineering Task Force (IETF)
Expired & archived
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Stream WG state WG Document
Document shepherd No shepherd assigned
IESG IESG state Expired
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


This document describes a proposed extension to SIP [1]. This exten- sion adds the 183 Session Progress response and a new header to indi- cate why a SDP message body is included in a 18x message. The introduction of the 183 informational response message would allow a called user agent to indicate to the calling user agent whether or not the calling user agent should apply local alerting for the session. The existing 180 Ringing message would indicate that the calling user agent has the option of providing local alerting (and generally should). The 183 Session Progress message would indi- cate that the calling user agent should not provide local alerting. In additionally, the calling user agent may be called on to establish a media session to be used by the called user agent to indicate the status of the session setup request as part of the indicated media stream. The indication of whether or not to play early media to the calling user would be controlled with a new Session header included in the 183 message.


Jonathan Rosenberg (
Henning Schulzrinne (
Matthew Cannon (
Steve Donovan (
Adam Roach (

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