IVR and DTMF problem

I have a Sangoma Vega 100G to connect to my PRI line. I’ve created a sip trunk in FreePBX. Inbound and Outbound working fine. However, when I create an IVR, the key presses do not get acknowledged and neither does anything go on the DTMF log. I know it must be something with the sangoma because when I try the same IVR with a sipgate trunk, it works fine.

On my sip trunk for the vega, it is set to dtmfmode=rfc2833

I have even tried dtmfmode=auto but nothing works.

One thing I noticed is when i press a key, it interupts the IVR message announcement

Any ideas what this can be?

After making the call, i’ve had a look at my Sangoma Vega logs and it seems that Vega recognizes the key dials because every key press I make, in the log it generates the following message:

(V)R29C00 [f1000533] (RFC2833) sending digit ‘1’

*** UPDATE ***

I’ve just been playing around with the settings on FreePBX. The SIP trunk connecting to the Vega was set to dtmfmode=rfc2833 and this matches the fact that the Vega log is showing that its sending rfc2833 digits.

I thought I would try changing trunk setting to dtmfmode=inband and now it seems to work.

Can anyone maybe explain why this may be?

try this