[asterisk-bugs] [Asterisk 0008736]: asterisk reinvites to G.711 after a T.38 negotiation - fax fails depending on ATA config

[noreply at bugs.digium.com]

The following issue has been ASSIGNED. 
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http://bugs.digium.com/view.php?id=8736 
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Reported By:                alex-911
Assigned To:                file
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Project:                    Asterisk
Issue ID:                   8736
Category:                   Channels/chan_sip/T.38
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     assigned
Asterisk Version:           1.4.2 
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Disclaimer on File?:        No 
Request Review:              
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Date Submitted:             01-05-2007 12:29 CST
Last Modified:              11-02-2007 10:06 CDT
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Summary:                    asterisk reinvites to G.711 after a T.38 negotiation
- fax fails depending on ATA config
Description: 
I have the following setup for outgoing fax calls to PSTN:

G3FAX - LinksysATA SPA-2102 - Asterisk 1.4 - SessionBorderController -
Cisco Class4 CA - Cisco AS series MG - PSTN

depending on the SPA config, there are several possibilities how T.38
calls are handled.

test 1 (test1.txt): next to T.38 enabled, there is FAX Passthru Method NSE
enabled. that forces the call setup like this: SPA invites for PCMA. the
Cisco MG detects fax and the Cisco  CA reinvites for T.38. in this
scenario, T.38 is negotiated and the fax is sent to the receiver. after the
fax has been sent, asterisk sends a reinvite for G.711 to the SPA-2102..?
the SPA sends BYE, the fax passed through. asterisk's reinvite didn't
disturb in this case, but what  was it good for?

test 2 (test2.txt): when I disable the FAX passthru Method on the
SPA-2102, the call setup is different: now it is the SPA itself who
reinvites for T.38 after it detects FAX locally on the line. here,
asterisks reinvites immediately for PCMA towards the call agent. the T.38
negotiation fails and no fax passes through.
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Issue History 
Date Modified   Username       Field                    Change               
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11-02-07 10:06  file           Status                   acknowledged => assigned
11-02-07 10:06  file           Assigned To               => file            
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