[asterisk-bugs] [Asterisk 0015262]: RFC3261 Via-header branches not done right (section

[Asterisk Bug Tracker]

The following issue has been SUBMITTED. 
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https://issues.asterisk.org/view.php?id=15262 
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Reported By:                maniax
Assigned To:                
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Project:                    Asterisk
Issue ID:                   15262
Category:                   Channels/chan_sip/General
Reproducibility:            sometimes
Severity:                   major
Priority:                   normal
Status:                     new
Asterisk Version:           Addons-1.6.1.0 
Regression:                 No 
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Request Review:              
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Date Submitted:             2009-06-03 09:51 CDT
Last Modified:              2009-06-03 09:51 CDT
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Summary:                    RFC3261 Via-header branches not done right (section
Description: 
We're testing asterisk and res_fax against a Zoiper Communicator and got
into a SIP issue. When there's a re-INVITE to T.38, the branch parameter is
the same as for the INVITE, which in fact is wrong, because:

RFC 3261, https://issues.asterisk.org/view.php?id=8.1.1.7 : "...the branch ID
was constructed in the fashion
described by this specification (that is, globally unique)."
https://issues.asterisk.org/view.php?id=17.2.3: "
The branch parameter in the topmost Via header field of the request
is examined.  If it is present and begins with the magic cookie
"z9hG4bK", the request was generated by a client transaction
compliant to this specification.  Therefore, the branch parameter
will be unique across all transactions sent by that client.
"

Attached is a packet capture that shows this - the re-invite is not
accepted by the softphone as it has the same branch parameter and is
treated as a retransmit.
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Issue History 
Date Modified    Username       Field                    Change               
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2009-06-03 09:51 maniax         New Issue                                    
2009-06-03 09:51 maniax         Asterisk Version          => Addons-1.6.1.0  
2009-06-03 09:51 maniax         Regression                => No              
2009-06-03 09:51 maniax         SVN Branch (only for SVN checkouts, not tarball
releases) => N/A             
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