Asterisk x100p echotraining

Echo Cancellation on the Wildcard X100P

If you are experiencing echo on the Digium Wildcard X100P, you can configure the Zap Channel Module to do echo cancellation training. Use the echotraining option in the Zap Channel Module’s configuration file. Note that this had a few issues before Dec 2, 2003 when Mark nailed down the bug that caused the DTMF to be unreliable.

Configuration

From the zapata.conf.sample:

; In some cases, the echo canceller doesn’t train quickly enough and there
; is echo at the beginning of the call. Enabling echo training will cause
; asterisk to briefly mute the channel, send an impulse, and use the impulse
; response to pre-train the echo canceller so it can start out with a much
; closer idea of the actual echo.
;
;echotraining=yes

If you set this to yes, use ztmonitor to adjust the rxgain and txgain. Ztmonitor isn’t installed by default; but it is included with the Zaptel source code, so look in /usr/src/zaptel. Use ztmonitor like this:

./ztmonitor 1 -v
Rx #################################* Tx

When there is echo on one side, both sides will have hashes even when one side is completely silent, like this:
Rx ################################ * Tx ##### *
The objective of using visual cues from ztmonitor to tune rxgain and txgain is so when you talk and remote mute, Tx side has visual bars but Rx side has nil; and vice versa.

Place a call, mute yourself and let the remote party talk. Adjust rxgain and txgain until the remote side no longer hears the echo. Then mute the remote party and you talk. Adjust again. You can do this on your own. It appears to me that txgain is more effective to control remote side echo, and rxgain is more effective to control Asterisk side echo.

For example, try this setting in zapata.conf:

rxgain=10.5
txgain=-4.5

Note: If you set the txgain value too low, your outbound calls may not go through since the DTMF tones are too quiet to be picked up.

Hope this helps with Wildcard X100P echo issues. I no longer have that 5-10 seconds of echo when making a call. HUGE IMPROVEMENT!

bkw dec 2, 2003

If echocancel=256 instead of 128(yes) then that could also be causing an echo + some terrible feedback. Cause I tried those same settings and was still getting echo. So try echocancel=yes, rxgain=4.5, txgain=4.5.

g powell Dec 30,2004

If you are unable to get rid of echo it is worth trying this: In the zconfig.h file a new zaptel echo canceller called ECHO_CAN_MG2 (MG2), Edit this file (found in /usr/src/zaptel on AAH) compile the driver and compile Asterisk – no echo at either end!!!