[asterisk-bugs] [Asterisk 0017878]: [patch] chan_sip fails to remove hold when receving a reINVITE without SDP

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=17878 
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Reported By:                frawd
Assigned To:                
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Project:                    Asterisk
Issue ID:                   17878
Category:                   Channels/chan_sip/Interoperability
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     confirmed
Asterisk Version:           1.6.2.11 
JIRA:                       SWP-2064 
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:             2010-08-17 11:05 CDT
Last Modified:              2010-08-17 18:35 CDT
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Summary:                    [patch] chan_sip fails to remove hold when receving
a reINVITE without SDP
Description: 
Patch for issue https://issues.asterisk.org/view.php?id=14448 never made it to
trunk so all versions above 1.4
suffer this problem.

Here is an updated patch for 1.6.2.11.
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Relationships       ID      Summary
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related to          0014448 [patch] chan_sip fails to remove hold w...
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 (0126055) frawd (reporter) - 2010-08-17 18:35
 https://issues.asterisk.org/view.php?id=17878#c126055 
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Sorry i hadn't seen issue https://issues.asterisk.org/view.php?id=14385 which
has exactly the same patch!

I've only seen that behavior in situations when the proxy wants to update
something in the call setup. It places the call on hold to stop the stream
and quickly sends an empty INVITE to force the UA (Asterisk) to renegotiate
the media session from zero by letting it send the SDP 'offer' (in the '200
OK').

As the call was placed on hold by the other side, it means Asterisk didn't
originally want that call to be on hold, so given the opportunity to send a
new offer, it should remove it.

I don't understand why it wasn't committed yet, as it's not such a bad
workaround for the time it might take to rethink important parts of SDP
handling (as in https://issues.asterisk.org/view.php?id=16254,
https://issues.asterisk.org/view.php?id=16313,
https://issues.asterisk.org/view.php?id=16373, and of course
https://issues.asterisk.org/view.php?id=17849).

It just fixes it! 

Issue History 
Date Modified    Username       Field                    Change               
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2010-08-17 18:35 frawd          Note Added: 0126055                          
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