Beep Sound Over POTS Line


I am experiencing a problem with a beeping noise/audio blank out while using Trixbox and would appreciate some advice on troubleshooting this issue. My system details are as follows:

P4 server with 2mb of RAM (dedicated physical server)
Openvox A400P card
POTS lines only for external (no SIP trunks)
System is located in China
Telecom carrier is China Telecom

The problem happens during every external call and can be described as follows:
The outside caller periodically hears a high-pitched beep
The internal caller (during the time that the external caller hears a beep) experiences a loss of both incoming and outgoing audio

I am guessing that this problem may be related to the OpenVox card, but I am not sure where to begin looking. Any advice would be most appreciated.



If you connect a phone directly to the POTS line, do you hear a beep? Is it coming from China Telecom or from your PBX?

It seems to be a problem with the PBX as the problem does not occur with just a phone plugged in. Also, we have four POTS lines connected to the interface card and the problem appears across all of them.

Any ideas what elements of the PBX system we should be looking at?



Which drivers are you using zaptel or dahdi?

We are using the zaptel drivers.

Any idea how I can look into the echo training issue?

In /etc/asterisk/zapata.conf

echotraining=800 <= number of mSec

There was a semicolon before that line in /etc/asterisk/zapata.conf
I have removed the semicolon, updated the file, and am testing it now.

Will let you know if this works, and thanks for the tip