[asterisk-bugs] [Asterisk 0012485]: Answer preferred codec only in SIP response

[noreply at bugs.digium.com]

The following issue has been SUBMITTED. 
====================================================================== 
http://bugs.digium.com/view.php?id=12485 
====================================================================== 
Reported By:                bamby
Assigned To:                
====================================================================== 
Project:                    Asterisk
Issue ID:                   12485
Category:                   Channels/chan_sip/CodecHandling
Reproducibility:            always
Severity:                   feature
Priority:                   normal
Status:                     new
Asterisk Version:           SVN 
SVN Branch (only for SVN checkouts, not tarball releases):  trunk 
SVN Revision (number only!):  
Disclaimer on File?:        N/A 
Request Review:              
====================================================================== 
Date Submitted:             04-21-2008 02:58 CDT
Last Modified:              04-21-2008 02:58 CDT
====================================================================== 
Summary:                    Answer preferred codec only in SIP response
Description: 
There is a following situation. The third party SIP gateway sends to
Asterisk INVITEs with codecs A and B in that order. Asterisk answers the
same A and B codecs. But gateway has internal policy to prefer the codec B
if possible and so it immediately sends reINVITE with codec B only. This is
undesirable behavior for the system. However Asterisk cannot be limited to
codec A only as there can be INVITEs with codec B only from the gateway and
they should be handled as well. The task is to avoid codec B when it is
possible at asterisk.

It would be nice that Asterisk is able to answer the most preferred codec
only in SIP response. This leaves no choice to the SIP gateway and thus the
reINVITEs are suppressed.

I've developed a patch that adds a global option to sip.conf that causes
the Asterisk to include the most preferred codec only in response.
====================================================================== 

Issue History 
Date Modified   Username       Field                    Change               
====================================================================== 
04-21-08 02:59  bamby          Asterisk Version          => SVN             
04-21-08 02:59  bamby          SVN Branch (only for SVN checkou =>  trunk       
  
======================================================================