[asterisk-bugs] [Asterisk 0015770]: faxing with T.38 fails

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=15770 
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Reported By:                Had
Assigned To:                kpfleming
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Project:                    Asterisk
Issue ID:                   15770
Category:                   Channels/chan_sip/T.38
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     assigned
Asterisk Version:           1.4.26.1 
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:             2009-08-24 12:10 CDT
Last Modified:              2009-08-24 15:28 CDT
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Summary:                    faxing with T.38 fails
Description: 
I have asterisk 1.4.26.1 setup with T.38 passthrough. I have linksys 2102
ATA and my provider use Cisco gateway with T.38 support enabled. Everytime
I send fax this fail with no apparent reason. 
In sip debug logs it looks that T.38 negotiation was successfull, later I
receive SIP BYE packet from provider and the call si hangup but no fax is
sent.
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 (0109542) kpfleming (administrator) - 2009-08-24 15:28
 https://issues.asterisk.org/view.php?id=15770#c109542 
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That log shows a gap of about 49 seconds between the T.38 reINVITE process
being completed and the BYE arriving; that would match up with the FAX
protocol's 'no response' timer, and would indicate that the FAX endpoints
could not communicate with each other. If you look at your packet capture,
at packet 1980 the SPA starts to send T.38 UDPTL packets with a 'no-signal'
indication, meaning the calling FAX machine is not sending any content. The
receiving machine is not sending any content at all, but I can see some
malformed T.38 packets being generated by Asterisk, so I'm still
investigating. 

Issue History 
Date Modified    Username       Field                    Change               
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2009-08-24 15:28 kpfleming      Note Added: 0109542                          
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