[asterisk-bugs] [Asterisk 0016756]: app_fax doesn't receive fax with T.38

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=16756 
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Reported By:                viniciusfontes
Assigned To:                
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Project:                    Asterisk
Issue ID:                   16756
Category:                   Applications/app_fax
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     feedback
Asterisk Version:           1.6.1.13 
JIRA:                       SWP-845 
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:             2010-02-02 13:56 CST
Last Modified:              2010-02-03 01:26 CST
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Summary:                    app_fax doesn't receive fax with T.38
Description: 
When I try to receive a fax from a provider that supports T.38 using
ReceiveFAX() provided by app_fax.so, the fax transmission ends prematurely
with an error.

What happens (according to Kevin Fleming) is this:

"In this call, Asterisk sent a re-INVITE to T.38 mode
from audio mode, the provider accepted it, and then Asterisk
acknowledged it. Immediately afterwards, Asterisk sent a re-INVITE
*back* to audio mode, which the provider accepted (and included T.38
capabilities in their response). Because of this, the FAX reception
process failed since the T.38 session was destroyed."
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 (0117596) raivisr (reporter) - 2010-02-03 01:26
 https://issues.asterisk.org/view.php?id=16756#c117596 
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WARNING[7880]: app_fax.c:178 phase_e_handler: Error transmitting fax.
result=13: Unexpected message received.

this is returned by spandsp, so looking at packet capture of failing
session might help to understand what went wrong and what is the unexpected
message that was received. use tcpdump/wireshark to capture session and
analyze it in wireshark telephony->voip calls 

Issue History 
Date Modified    Username       Field                    Change               
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2010-02-03 01:26 raivisr        Note Added: 0117596                          
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