[Asterisk-Users] how do i get rid of this blasted echo !!!

[Brett, Gary]

Any help on this would be great

I have 2 TDM400P's, 2 asterisk servers (running on powerful boxes with FC1
and * v CVS 1.0.02), and 4 analogue PSTN lines from BT and whatever I do, I
cannot get rid of this damn local echo. Ive tried setting the echoTraining,
echoCancel (in phone.conf and Zapata.conf) , echocancelwhenbridged to every
possible combination , Ive even tried running the fxotune utility to no
avail. Ive swapped cards, telephone lines, servers and also tried different
phones (budgetone, x-lite, 7940) but still it's the same.

Does anybody have any other suggestions as this is driving me up the wall 

Cheers
Gary