[asterisk-dev] DTMF / SIP / snom phones

[Dave Hawkes]

Hi all,

I've been having problems accessing external IVRs using snom phones with 
asterisk. I tracked the problem down to the snom generating an inband 
tone as well as asterisk generating a tone in response to either RFC2833 
   signalling or SIP info messages. It would appear that the only way to 
prevent the snom sending inband signalling is to press mute before using 
an IVR.

I tried using the snom with asterisk configured for inband signalling, 
however asterisk frequently detects two key presses where there is only 
one and that is just as bad, though the inband tones are filtered.

Pressing mute is not an ideal situation and a better remedy would be to 
  enable the tone filtering that occurs when asterisk is not actually 
set for inband signalling. Does anyone know if there is this is 
feasible? Or better still how to do it? If it is feasible I'll take a 
look at the code and hack something in...

Thanks
Dave Hawkes