[Asterisk-Users] inband DTMF with IAX

[Alex Brett]

Hi,

I am currently having a problem where I am making outbound calls via 
IAX, these calls are then being routed by my provider through a SIP 
connection to a service providing PSTN access.

The problem I have is the the DTMF is being sent inband over the SIP 
connection, and I am only receiving the DTMF inband on my IAX connection 
which asterisk is sensibly ignoring as from what I understand with IAX2 
the DTMF should be sent out-of-band.

I assume the simplest way to fix it is for my provider to put a 
dtmfmode=inband on the sip.conf entry for their PSTN provider, then 
presumably their asterisk would see the DTMF and send them out-of-band 
over the IAX2 channel, however, they are understandably wary of doing 
this in case it affects any of their other services which currently work 
perfectly...

Is there any way to get Asterisk to listen for inband DTMF from an 
outbound IAX2 channel so that I can get round this problem in a simple way?

(The reason I need to get DTMF on an outbound call is I am trying to set 
up a 'press 1 to accept the call' system for forwarding calls to mobiles).

Thanks in advance,
Alex Brett
alex.brett at loho.co.uk