DTMF over IAX Trunk problems

First of all let me explain my setup; I have 3 locations all tied together with IAX trunks and Location A serves out a PRI and an AGI application.

It seems that ever since upgrading to 1.4.15 from a 1.2 installation, I cannot get reliable DTMF detection in my AGI application when accessing it from Location B and C. The AGI application still works fine from Location A. So I’m thinking that it has something to do with the IAX trunks not sending DTMF properly.

I did some reading and set jitterbuffer=no in my iax.conf to make sure that isn’t the problem. No dice.

I started doing some more reading and I believe the problem may be related to the variable length DTMF implementation into IAX. But I have no idea how to solve it.

The problem seems to exist whether or not I use AGI or standard dialplan to read the DTMF.

I have verified that I am not sending both rfc2833 and inband from my phones

I dunno, the whole problem is spinning me in circles. Can anyone help?

Anybody know if it would help if I converted from IAX trunks to SIP trunks?