[Asterisk-Users] DTMF problems with Zaptel T100P

[Nick Eggleston]

We've got an asterisk system hooked up to a number of telephones via a channel
bank.

[*]T100P---CAC(access bank)---Phones...

What we are seeing is problems with DTMF tone detection on some (but not all) of
the FXS ports.  In our testing, we plugged a simple analog phone into each of
the first 10 ports, called outside the syatem, and listed while the user
depressed the "5" key for four seconds.

What we expect to hear on the remote-end is four seconds of DTMF tone.  That is
what the local user hears.

On some of the ports we do indeed hear four seconds of continuous DTMF.
On one port, we only hear about 1/2 second of DTMF followed by 3.5 seconds of
silence.
On anohter port, we hear about 3.5 seconds of silence, followed by 0.5 seconds
of DTMF.
On another port, we hear 4 seconds of DTMF interrupted by blips of silence.

When not playing DTMF tones, we can hear just fine.

Has anyone else had these symptoms?

Can anyone suggest a way to debug this?

Thanks!
-- 
Nick Eggleston
Consultant
Data Communications Consulting, Inc.
6320 Rucker Road, Suite E
Indianapolis, IN  46220
317/726-0295 x18
317/202-2445 (fax)