[asterisk-bugs] [Asterisk 0015773]: SendFax without reliable transmission.

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=15773 
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Reported By:                ChrisDE
Assigned To:                kpfleming
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Project:                    Asterisk
Issue ID:                   15773
Category:                   Applications/app_fax
Reproducibility:            random
Severity:                   major
Priority:                   normal
Status:                     assigned
Asterisk Version:           SVN 
Regression:                 No 
SVN Branch (only for SVN checkouts, not tarball releases): 1.6.0 
SVN Revision (number only!): 213837 
Request Review:              
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Date Submitted:             2009-08-24 14:14 CDT
Last Modified:              2009-08-24 14:22 CDT
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Summary:                    SendFax without reliable transmission.
Description: 
Using sendfax application there are random transmission errors.

Transmission has been tested extensively with different carriers,
different documents and also different asterisk versions but same results.


In some cases (approximately 50% of the cases) fax transmission is
SUCCESSFUL
In other cases (approx. 10%) fax transmission ends with

WARNING[14167]: app_fax.c:178 phase_e_handler: Error transmitting fax.
result=21: No response after sending a page.

in approx. 40% I get

WARNING[16247]: app_fax.c:178 phase_e_handler: Error transmitting fax.
result=20: Received no response to DCS or TCF.

Because only 50% of the faxes pass with OK the functionality is not
reliable and the severity of this problem is major.
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 (0109538) kpfleming (administrator) - 2009-08-24 14:22
 https://issues.asterisk.org/view.php?id=15773#c109538 
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This cannot be a 'major' issue, as it does not affect the proper operation
of Asterisk itself or any channel driver.

Please keep in mind that app_fax is just a wrapper around the FAX
functionality of the spandsp library; there isn't any code in Asterisk that
actually implements any FAX protocol. If the failures you are experiencing
are FAX protocol errors, you'll have to work with the author of spandsp to
troubleshoot them.

Your debug1 and debug2 logs don't include enough information to actually
see if there was any negotiation problems; if you are going to upload a
log, please use 'core set verbose 10', 'core set debug 10' and 'sip set
debug on', and ensure that your console logger channel has all the logger
levels enabled (debug, verbose, and all the rest).

Your debug3 log is from an older revision of Asterisk 1.6.0 and exhibits
an SDP formatting problem that does not exist in current revisions. 

Issue History 
Date Modified    Username       Field                    Change               
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2009-08-24 14:22 kpfleming      Note Added: 0109538                          
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