[Asterisk-Users] Talkoff (Spurious DTMF) with 1.0.9.2 and TE406P

[Matthew Fredrickson]

On Oct 18, 2005, at 2:03 AM, George Pajari wrote:

> We recently migrated a couple of PRIs to Asterisk 1.0.9.2 and a TE406P 
> and are getting reports of talkoff (spurious/random DTMF tones heard 
> by people on SIP equipment connected to the Asterisk server. We 
> previously were using 1.0.3 with a T100P without any talkoff.
>
> (a) We have not set relaxdtmf.
> (b) There is no apparent pattern to the problem (seems to affect users 
> on ATAs as well as SIP phones from different manufacturers).
>
> Any suggestions?
>
Digium support can also help you with this, but as you load the module, 
there is a
parameter that you can adjust the "relaxedness" of DTMF detection.  It 
is called dtmfthreshold and it defaults to 1000.  The higher that it is 
set to makes it more stringent in DTMF detection (i.e., less likely to 
have talk off).  At about 2000-2500, most people
stop getting DTMF events altogether, so that might be the range that 
you want to play around with.

---
Matthew Fredrickson