[asterisk-bugs] [Asterisk 0011483]: Asterisk rejects legitimate G.729a call with 488 Not Acceptable Here

[noreply at bugs.digium.com]

A NOTE has been added to this issue. 
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http://bugs.digium.com/view.php?id=11483 
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Reported By:                revolution
Assigned To:                
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Project:                    Asterisk
Issue ID:                   11483
Category:                   Core/RTP
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     new
Asterisk Version:           1.4.15  
SVN Branch (only for SVN checkouts, not tarball releases): N/A  
SVN Revision (number only!):  
Disclaimer on File?:        N/A 
Request Review:              
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Date Submitted:             12-06-2007 09:33 CST
Last Modified:              12-07-2007 02:39 CST
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Summary:                    Asterisk rejects legitimate G.729a call with 488 Not
Acceptable Here
Description: 
Linksys/Sipura brand phones send rtpmap:18 as G729a (other brands may as
well). Although technically legitimate and correct, INVITE is being
rejected with 488 Not acceptable here -- i.e. no compatible codecs despite
the fact that realtime sip peer is set to allow g729.

After going into Linksys/Sipura SPA-941 (as well as SPA-2100) and altering
name of rtpmap:18 to G729 (sans the a) -- call was accepted and completed
as expected.

Attaching two capture files (for the rejected call and the accepted call)
as well as a patch to rtp.c which seems to fix this minor issue (mostly
just an annoyance).
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---------------------------------------------------------------------- 
 srl100 - 12-07-07 02:39  
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RFC 3551 says:

   The speech coding
   algorithms in the main body of G.729 and in G.729 Annex A are fully
   interoperable with each other, so there is no need to further
   distinguish between them.  An implementation that signals or accepts
   use of G729 payload format may implement either G.729 or G.729A
   unless restricted by additional signaling specified elsewhere related
   specifically to the encoding rather than the payload format.

So it would appear that the Linksys/Sipura hardware is being somewhat
non-standard in it's rtpmap statement for G.729. 

Issue History 
Date Modified   Username       Field                    Change               
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12-07-07 02:39  srl100         Note Added: 0075010                          
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