[Asterisk-Users] X100P and echo cancelation

[Dan]

Hi,

Using a Cisco SIP phone to make a PSTN call through an X100P card, a small
echo can be heard in the phone. The other party does not have this problem.
I have echo cancelation switch in the zapata.conf file to on.

echocancel=yes
echocancelwhenbridged=yes

What else can be done to make this anoying echo dissapear?
It is not a strong echo, but it can be much better without it....

Thanks,
Dan