[Asterisk-Users] DTMF Simultaneous Inband and RFC2833 performedby Asterisk => Duplicate tones

[steve at daviesfam.org]

On Thu, 19 Jan 2006, Andreas Sikkema wrote:

> The same thing can happen when a SIP "ATA" is configured to 
> use rfc2833 but is also a little to lote with the filtering 
> out of the DTMF. So sometimes it's not Asterisks fault at 
> all ;-)
> 
> And then there's some IVR's that don't notice it at all, while others 
> are totally unusable.


Obviously we can't do anything about the ATA.

But I did have an idea for Asterisk...

Which is that when the DTMF detector spots DTMF in an audio frame, that it 
passes along on the channel a kind of "merged frame" which is both the 
detected DTMF AND the actually audio.  Then, when the frame arrives at an 
application of a channel that wants the indication, it can use that.  On 
the other hand, if the frame arrives at a channel that needs to send 
inband DTMF, the indication can be ignored and the original audio passed 
on instead.

Steve