[Asterisk-Users] Sending DTMF out-of-band over IAX2

[Steven Critchfield]

On Tue, 2004-02-10 at 08:53, Mark Johnston wrote:
> I am planning to deploy a fairly standard PSTN-dodging setup, like this:
> 
> T1 - * - IAX2 - * - T1
> 
> In other words, two Asterisk boxes with T100Ps, interconnected with IAX2,
> used for bridging calls from one PSTN endpoint to the other.  What makes
> this interesting is that on the receiving end, there is an IVR that isn't
> under my control, so DTMF has to pass between the boxes.
> 
> I'd like to use GSM to save bandwidth, but I know DTMF won't survive
> anything less than alaw.  Is there a way for the sending Asterisk to pick
> up DTMF from the inbound Zaptel channel, send it out-of-band across the
> IAX2 link, and have the receiving Asterisk synthesize the DTMF on the
> outbound Zaptel?  I know all of the components (DTMF decoding, out-of-band
> transmission, and synthesizing) are there in Asterisk, but I don't know
> how to make them work together to accomplish my goal.

It is there and just works. IAX doesn't let you try and send the DTMF
inband.
-- 
Steven Critchfield  <critch at basesys.com>