[asterisk-bugs] [Asterisk 0018677]: T38 passthrough doesn't work in glare reinvite situation

[Asterisk Bug Tracker]

The following issue has been SUBMITTED. 
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https://issues.asterisk.org/view.php?id=18677 
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Reported By:                mdu113
Assigned To:                
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Project:                    Asterisk
Issue ID:                   18677
Category:                   Channels/chan_sip/T.38
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):  1.4  
SVN Revision (number only!): 302311 
Request Review:              
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Date Submitted:             2011-01-25 16:02 CST
Last Modified:              2011-01-25 16:02 CST
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Summary:                    T38 passthrough doesn't work in glare reinvite
situation
Description: 
Have the following situation:
000011206003 (cisco 1751+fxs with t38 enabled) <-> asterisk <-> sipp1
(ITSP)
ITSP is using Cisco AS5400 to terminate sip calls to PSTN and has T38
enabled
The problem is that both cisco devices detect fax tones (and send T38
reinvites) almost concurrently and that seems to confuse asterisk. I see
the following logged on the console:
[Jan 25 16:03:21] WARNING[5956] chan_sip.c: Failed to read an alternate
host or port in SDP. Expect audio problems
[Jan 25 16:03:21] WARNING[5956] chan_sip.c: Failed to set an alternate
media source on glared reinvite. Audio may not work properly on this call.
When it happens fax 100% fails. When it doesn't happen fax works very
reliably

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Issue History 
Date Modified    Username       Field                    Change               
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2011-01-25 16:02 mdu113         New Issue                                    
2011-01-25 16:02 mdu113         Asterisk Version          => SVN             
2011-01-25 16:02 mdu113         Regression                => No              
2011-01-25 16:02 mdu113         SVN Branch (only for SVN checkouts, not tarball
releases) =>  1.4            
2011-01-25 16:02 mdu113         SVN Revision (number only!) => 302311          
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