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Requesting Answering Modes for the Session Initiation Protocol (SIP)

Approval announcement
Draft of message to be sent after approval:


From: The IESG <>
To: IETF-Announce <>
Cc: Internet Architecture Board <>,
    RFC Editor <>, 
    sip mailing list <>, 
    sip chair <>
Subject: Protocol Action: 'Requesting Answering Modes for the 
         Session Initiation Protocol (SIP)' to Proposed Standard 

The IESG has approved the following document:

- 'Requesting Answering Modes for the Session Initiation Protocol (SIP) '
   <draft-ietf-sip-answermode-08.txt> as a Proposed Standard

This document is the product of the Session Initiation Protocol Working 

The IESG contact persons are Cullen Jennings and Jon Peterson.

A URL of this Internet-Draft is:

Ballot Text

Technical Summary 

This document defines extends SIP with two header fields and associated 
option tags that can be used in INVITE requests to convey the requester's
preference for user-interface handling related to answering of that
The first header, "Answer-Mode", expresses a preference as to whether the
target node's user interface waits for user input before accepting the 
request or instead accepts the request without waiting on user input. The
second header, "Priv-Answer-Mode" is similar to the first, except that it
requests administrative-level access and has consequent additional 
authentication and authorization requirements. These behaviors have 
applicability to applications such as Push-to-Talk and to diagnostics 
like loop-back. Usage of each header field in a response to indicate 
how the request was handled is also defined. 

Working Group Summary 

There is consensus in the working group to publish this document. The 
proposal was originally submitted as a P-header, but it was decided that 
this aspect should be brought out and made generally applicable to all 
SIP implementations. Early concerns about the possibility to use the 
header as a means of eavesdropping have been addressed in the 
security considerations.

Document Quality 

There has been no indication of implementation. The document has been 
required in support of the OMA PoC feature, and it can be assumed that
there  have been implementations of the OMA work that have therefore
used this feature. 


The document shepherd for this document was Keith Drage. The responsible
Area Director was Cullen Jennings.

RFC Editor Note