[asterisk-users] wrond DTMF detection on Zap channel

[nik600]

Dear all

i have a TE205P connected to an Asterisk 1.2.18.

Yes i know, the version is old but since now the system was stable and
i don't have the necessity of an upgrade.

The system provide an IVR service that:

1) receive the call
2) verify the queue length
3) hangup if queue length is > 1
4) put the call in the queue othervise

Then, there is an AGI php script that
1) verify the queue
2) wait 5 seconds if the queue is empty
3) pick-up a call from the queue and transfer it to an extension othervise

Finally, the extension lanuch another AGI php script that requires
some DTMF tone to the user to perform some actions.
This system is working properly since 2006.

Well, the problem during last days is that it seems that sometimes the
DTMF recognition doesn't work, in the debug i get:

 AGI Tx >> 200 result=0

But users complains to me because they assure to have digited
something different than 0.
The problem seems to be reproducible when the system is loaded (i
don't have information on the SO but we receive abut 2500 calls per
hour each call is very short because usually it is hangup after a very
short time, as the queue length is very often 1)

It's not an AGI application problem as i get the "wrong" dtmf tone
directly from Asterisk.
It's not a phone problem as the same phone may retry and then it works.

Is it possible to relate it with the load of the server?

Can you suggest me something?

Thansk

-- 
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nik600
http://www.kumbe.it