Summary:ASTERISK-16705: T.38 Fax Fallback to Pass-Through didn't work
Reporter:sybasesql (sybasesql)Labels:
Date Opened:2010-09-21 07:22:24Date Closed:2011-07-26 15:31:34
Versions:Frequency of
Environment:Attachments:( 0) t38-fallback-pass-through.zip
Description:Dear All!

OS: CentOS 5.5 x86_64
Asterisk: x86_64

ISP: T.38 fallback g711alaw
ASTERISK: t38pt_udptl=no

I have problem with T.38 reinvite: When we received reinvite from ISP, we answered 488 Not accptable here and ASTERISK begin send UDPTL instead of G711 RTP.

I attached call trace to view in wireshark.
Comments:By: Leif Madsen (lmadsen) 2010-09-21 14:00:07

This is not a blocking issue. Block should only be set by bug marshals.

By: sybasesql (sybasesql) 2010-09-22 03:23:12

Added an excerpt from the RFC3261 for this behavior:

"If a UA receives a non-2xx final response to a re-INVITE, the session parameters MUST remain unchanged, as if no re-INVITE had been issued."

But ASTERISK begin send UDPTL packets instead of RTP G711 as seen from attached trace file t38-fallback-pass-through.zip.

By: Matthew Nicholson (mnicholson) 2011-07-26 15:31:12.564-0500

Per the Asterisk maintenance timeline page at http://www.asterisk.org/asterisk-versions maintenance (bug) support for the 1.4 and 1.6.x branches has ended. For continued maintenance support please move to the 1.8 branch which is a long term support (LTS) branch. For more information about branch support, please see https://wiki.asterisk.org/wiki/display/AST/Asterisk+Versions

If this is still a bug in 1.8, open a new issue.