[asterisk-bugs] [Asterisk 0012414]: Asterisk replies with "No compatible codecs" for t.38 Re-INVITE

[noreply at bugs.digium.com]

The following issue has been SUBMITTED. 
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http://bugs.digium.com/view.php?id=12414 
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Reported By:                MVF
Assigned To:                
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Project:                    Asterisk
Issue ID:                   12414
Category:                   Channels/chan_sip/T.38
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     new
Asterisk Version:           SVN 
SVN Branch (only for SVN checkouts, not tarball releases):  1.4  
SVN Revision (number only!): 114035 
Disclaimer on File?:        N/A 
Request Review:              
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Date Submitted:             04-10-2008 16:55 CDT
Last Modified:              04-10-2008 16:55 CDT
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Summary:                    Asterisk replies with "No compatible codecs" for
t.38 Re-INVITE
Description: 
I have an Asterisk (SVN) peering calls between two proxies. Incoming calls
are sent to terminating proxy and routed from there to different brand GWs.
Some of these gateways are Asterisk GW and others are Addpac GW. 
I found that for fax call the re-invite coming from terminating Asterisk
GW is successfully handled by peering Asterisk but the re-invite from
Addpac GW is dropped with "488 Not acceptable here". 
The only difference that I can see between the re-invites is in SDP, the
one coming from Addpac GW don't have "a" fields after the "m" field of SDP
like Asterisk do.

Asterisk Re-Invite SDP:
v=0
o=root 31588 31590 IN IP4 10.10.20.126
s=session
c=IN IP4 10.10.20.126
t=0 0
m=image 4208 udptl t38
a=T38FaxVersion:0
a=T38MaxBitRate:9600
a=T38FaxFillBitRemoval:0
a=T38FaxTranscodingMMR:0
a=T38FaxTranscodingJBIG:0
a=T38FaxRateManagement:transferredTCF
a=T38FaxMaxBuffer:400
a=T38FaxMaxDatagram:400
a=T38FaxUdpEC:t38UDPRedundancy

Addpac Re-Invite SDP:
v=0
o=005622457495 1207839041 1207839041 IN IP4 10.10.20.83
s=AddPac Gateway SDP
c=IN IP4 10.10.20.83
t=1207839041 0
m=image 24086 udptl t38

After receiving re-invite from Addpac GW I see:
[Apr 10 14:50:42] NOTICE[29023]: chan_sip.c:5493 process_sdp: No
compatible codecs, not accepting this offer!

Please check the attached sip debug for complete detail of these two
calls.
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Issue History 
Date Modified   Username       Field                    Change               
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04-10-08 16:56  MVF            Asterisk Version          => SVN             
04-10-08 16:56  MVF            SVN Branch (only for SVN checkou =>  1.4         
  
04-10-08 16:56  MVF            SVN Revision (number only!) => 114035          
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