Review Board 1.7.16

Improved support for T38 on initial INVITE

Review Request #208 - Created March 25, 2009 and submitted

Joshua Colp
This change improves our handling of T38 when we get it on an initial INVITE.

Previously we would try to setup a T38 only session end to end (between both endpoints) if the incoming call offered T38 (even if it also offered audio).

This change makes chan_sip respond appropriately to the incoming INVITE. If we get an offer with both T38 and audio, we setup both a T38 and audio session.
We do not, however, setup a T38 and audio session on a subsequent outgoing channel. We setup an audio only session. If the incoming channel sends us UDPTL
though we immediately trigger a reinvite on the outgoing channel to T38.

This seems to be the best compromise I can come to.
A few users have tested this change in their environments to confirm it works. I have also confirmed that the new behavior is present when T38 is present in the initial INVITE with my T38 test setup here.
Review request changed
Updated (March 25, 2009, 4:27 a.m.)
  • changed from /trunk to /branches/1.4
Ship it!
Posted (March 25, 2009, 9:35 a.m.)
Looks good to my eyes. The positive testing improves my confidence, too. Good job, Josh! runs on a server provided by Digium, Inc. and uses bandwidth donated to the open source Asterisk community by API Digital Communications in Huntsville, AL USA.
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