[asterisk-users] Re: DTMF detection problems on PRI channels?

[Tony Mountifield]

In article <010501c75ce6$e5146120$64fe1fac at ocg.ca>,
Michelle Dupuis <support at ocg.ca> wrote:
> Sounds like the DTMF tones are too far from spec, or noisy.  Is the DTMF
> being transcoded somewhere along the way?
> 
> If you have time to kill....try to separate the two frequencies in your
> software (I don't know goldwave) - are both present and clean and same
> amplitude and on freq?  Remove the two frequencies and what's left?  If
> there's a lot of noise, then the other party is doing a bad job encoding the
> DTMF.  Otherwise we can start to chase your machine causes

In the few examples I looked at recently, the audio appeared to be clean
and well-formed. Notching the two frequencies left very little.

The system is using E1 TDM interfaces with aLaw encoding.

I see there is a define called OLD_DSP_ROUTINES which causes conditional
compilation in dsp.c, and is defined or not in the Makefile. Is it worth
trying the old routines? What are the main differences between the old
and the new?

Cheers
Tony

-- 
Tony Mountifield
Work: tony at softins.co.uk - http://www.softins.co.uk
Play: tony at mountifield.org - http://tony.mountifield.org