Does anyone have any idea what would cause distorted audio but ONLY for
DTMF tones coming in over our analog lines. (The analog interfaces are
X100P's). I have carefully adjusted the gains in the zapata.conf using
a local test line after trying various settings with no gain or just
random gain settings. RelaxDTMF has no effect. I set up a monitor
command in my dial plan to capture separate In and Out audio streams
during the main menu portion of my IVR so I can listen to the tones
being played.
On most calls, the tones appear to be detected properly and are muted
out of the audio stream (except for a slight click at the beginning of
the tone). For problem calls, the tones can be heard in the audio
stream as terribly distorted. sometimes the distortion is like the tone
being echoed back over itself with some sort of pitch shift, other times
the distortion is like the tone is being over-amplified. The unusual
thing is that regular audio on these calls is fine.
I'm using Asterisk 1.4.18.1, Zaptel 1.4.9.2 built with Oslec SVN running
under Centos 5.0 (runlevel 3 to rule out interference from X Windows) on
an AMD Athlon 64 4000 with 2 gigs ram.
I can provide audio examples to anyone that is interested.
Thanks,
Brent Davidson
