[asterisk-bugs] [Asterisk 0018957]: Calls from VOIP to Dahdi requiring transcoding fail

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=18957 
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Reported By:                clint
Assigned To:                
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Project:                    Asterisk
Issue ID:                   18957
Category:                   Channels/chan_dahdi
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     new
Asterisk Version:           1.8.3 
JIRA:                        
Regression:                 No 
Reviewboard Link:            
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Request Review:              
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Date Submitted:             2011-03-10 21:18 CST
Last Modified:              2011-03-21 12:14 CDT
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Summary:                    Calls from VOIP to Dahdi requiring transcoding fail
Description: 
A call which originates on VOIP (SIP, IAX tested) and terminates via Dahdi
will fail if codec other than ulaw is used on VOIP leg of call.

https://issues.asterisk.org/view.php?id=18242 is a subset of this issue - that
issue refers specifically to
DISA having this problem, however the problem exists whenever a call is
bridged from VOIP to Dahdi.  Creating a new issue to highlight the wider
scope of the bug and clarify that it is not DISA related.
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Relationships       ID      Summary
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related to          0018242 DISA "Cannot handle frames in gsm ...
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 (0133043) clint (reporter) - 2011-03-21 12:14
 https://issues.asterisk.org/view.php?id=18957#c133043 
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While the above patch does indeed stop the error from appearing, the guy
who thought that the codec check would be useful in the first place needs
to chime in here with an explanation of the motivation behind the check. 
Otherwise, the above patch would be more correct in simply removing the
if() statement altogether.

Additionally, the subsequent code seems to depend upon the call being in
either slin or u/alaw.

So I don't think the above patch is correct. 

More likely, the problem is that for some reason, when asterisk is
presenting indication, the leg of the call on dahdi (the outbound leg in
the case above) is being flagged with the codec of the inbound (voip) leg,
causing dahdi_write to blow up.  It is clear that this flag is being set in
a manner inconsistent with reality, as if the frames were truly not in one
of the acceptable formats, something would blow up further down the road
after we ignore the format per the patch above. 

Issue History 
Date Modified    Username       Field                    Change               
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2011-03-21 12:14 clint          Note Added: 0133043                          
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