Echo on Linksys SP941 IP Phone

When you say you're calling in is this on an FXO port in the asterisk box? T1? SIP?

If you're calling in on a zaptel port (FXO, T1, or any other PSTN connect) you'll want to check a couple things.
Make sure you get the latest zaptel driver (svn is the best but stable is fine as well)
Edit the zconfig.h and make sure you are using
#define ECHO_CAN_MG2
as the echo anceller and comment out the rest.

Recompile the zaptel driver, unload and reload the modules, and restart asterisk.

MG2 has made some huge echo cancelling improvements.

Also make sure in your zapata.conf you have
echocancel=yes
echotraining=yes (or 800)
rxgain=0.0
txgain=0.0

This is where you want to start for testing.

From here place a call and run ztmonitor from the zaptel source directory:
./ztmonitor <zaptel channel number> -v

This will show you the RX and TX gains. The general setting would be to have both about in the middle, but it varies what will help echo. Watch the ### movement to see if you are hitting extremely high or extremely low while talking. From there adjust the rxgain and txgain in the zapata.conf to increase or decrease the db as needed. By properly getting the rxgain and txgain set you will see a huge decrease in echo.

Normal situations you will see rxgain require a higher value than the txgain. It's just going to be a large amount of trial and error to find something that works on your lines.

Make sure you restart asterisk after editing the zapata.conf as a simple reload does not make the new changes take effect.

Chris

thanks in advance chrsitsis...I'll try everything you listed here.

btw, this is my first asterisk server so bare with me since i'm still a noob.

AS for calling, I'm currently testing my settings on an FXO port but will be deploying the Asterisk server using a T1 line in a few weeks.

will the echo settings have different results on either a T1 or FXO port?

thanks for the prompt help!