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[brent at texascountryt...]

Still grasping at straws trying to solve DTMF detection issues with one
of my asterisk servers. This particular server is now running Asterisk
1.4.18.1 and Zaptel 1.4.9.2 in runlevel 3 (console only) with 2 X100P
cards. I have tried adjusting channel gains, turning call progress and
relaxdtmf on and off, switching echo cancelers, just about everything
that Google turns up and I can't seem to solve the problem.

If I turn relaxDTMF off then most incoming calls from Cell Phones cannot
navigate our menu and I get doubled digits showing up in the log. With
it enabled 99% of calls work correctly, but a few of the calls do not
show ANY dtmf digits being passed at all. I have debug and verbose both
set to 20 and have several debugging NoOps set in the dial plan to add
some call-flow tracking to the log. When someone calls in that has
problems with DTMF our main greeting plays all the way through and the
WaitExten times out and they are sent to our operator extension. I'm
not 100% sure yet if this is relavant, but the majority of the people
experiencing this problem are calling in from locations that have their
own internal PBX systems. Is there maybe a way to further relax the
DTMF detection?

Thanks,
Brent Davidson

[brent at texascountryt...]

To add some further details to this thread I set up a "Monitor" command
that records just the IVR portion of an incoming call. I left the m
flag off so I could listen to the incoming audio separate from the
outgoing recording. On calls where the DTMF detection works correctly I
only hear extremely short clips of the DTMF tone in the incoming audio
sample. They usually sound like just a click in the audio stream but
there is a hint of the DTMF tone in the background. I'm assuming that
Asterisk and/or my X100P is recognizing the DTMF tones immediately and
muting them out of the audio path as soon as they are detected. What
gets left behind is just the initial sample.

The calls where DTMF detection is not working sound completely
different. The tones in those audio streams are very loud and very
distorted. It sounds almost like an old Atari 2600 video game instead
of DTMF tones. The odd thing is that I can hear a hint of the correct
tone in the background of the audio. When the caller is routed to the
operator extension the voice audio quality is fine. Also, our outgoing
greeting is noticeably quieter than the incoming DTMF tones so it
shouldn't be interfering. I currently have rxgain set at 0.0 and have
to set txgain to 4.5 or callers complain that our outgoing audio is too
quiet.

As much as I would love to say this is a problem with the Caller's PBX I
just don't see how that's possible. They never had any problems calling
us with our old phone system, and it is not limited to any one caller.

Thanks,
Brent Davidson

Brent Davidson wrote: