Re: Question about significance of header(Supported: timer, 100rel)
Rashid Shakil <rashidshakil <at> yahoo.com>
2010-10-04 12:26:54 GMT
Thanks for the detailed response, very helpful ...
--- On Fri, 10/1/10, Maddipatla, Maheswara Rao (Mahesh) <mmaddipatla <at> avaya.com> wrote:
From: Maddipatla, Maheswara Rao (Mahesh) <mmaddipatla <at> avaya.com>
Subject: RE: [Sip-implementors] Question about significance of header(Supported: timer, 100rel)
To: "Rashid Shakil" <rashidshakil <at> yahoo.com>, sip-implementors <at> lists.cs.columbia.edu
Date: Friday, October 1, 2010, 10:55 PM
The Supported header field contains a list of option tags (timer,100rel,replaces,histinfo,join
...)that are understood by the UAC or UAS .
If a UAC wants to inform UAS about his capability of supporting/exchanging SIP extensions it will add those
in the Supported header and sends in the INVITE message .Supported header doesn't have impact on the call
since UAC doesn't insist UAS and its optional as well. Where as Require: header insists UAS and It becomes
mandatory for other party to respond .
If 100rel is enabled on both ends either calling or called party can include Supported :100rel or Required :
100rel in INVITE or subsequent 1xx message to show that it supports PRACK messages .Refer rfc3262 for
From: sip-implementors-bounces <at> lists.cs.columbia.edu