[asterisk-bugs] [Asterisk 0018956]: SDP origin attribute modified when issuing re-INVITE because of directmedia=yes

[Asterisk Bug Tracker]

The following issue has been SUBMITTED. 
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https://issues.asterisk.org/view.php?id=18956 
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Reported By:                saghul
Assigned To:                
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Project:                    Asterisk
Issue ID:                   18956
Category:                   Channels/chan_sip/Interoperability
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     new
Asterisk Version:           SVN 
JIRA:                        
Regression:                 No 
Reviewboard Link:            
SVN Branch (only for SVN checkouts, not tarball releases): 1.8 
SVN Revision (number only!): 310240 
Request Review:              
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Date Submitted:             2011-03-10 17:18 CST
Last Modified:              2011-03-10 17:18 CST
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Summary:                    SDP origin attribute modified when issuing re-INVITE
because of directmedia=yes
Description: 
When directmedia=yes is set Asterisk will generate a re-INVITE with a new
SDP offer to both parties. This offer must not modify the SDP origin
attribute (o=) but for the version number. Extract from RFC3264, sec 8:

"When issuing an offer that modifies the session,
  the "o=" line of the new SDP MUST be identical to that in the
  previous SDP, except that the version in the origin field MUST
  increment by one from the previous SDP."

The attached SIP trace from the CLI shows the described behavior.
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Issue History 
Date Modified    Username       Field                    Change               
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2011-03-10 17:18 saghul         New Issue                                    
2011-03-10 17:18 saghul         Asterisk Version          => SVN             
2011-03-10 17:18 saghul         Regression                => No              
2011-03-10 17:18 saghul         SVN Branch (only for SVN checkouts, not tarball
releases) => 1.8             
2011-03-10 17:18 saghul         SVN Revision (number only!) => 310240          
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