[Asterisk-Users] Echo Problem

[Brian M. Arlinghaus]

I've got mostly Cisco 7960s and a few Analog phones 
on TDM Ports.  On the 7960s, the echo is quite bad. 
On the TDM ports, it is there, but not as bad.  I have 
tried setting echo cancellation to various numbers, but 
have had no luck.

This began after a HEAD version of * was installed. 
Since then, I installed what I think is the latest stable 
version (Asterisk CVS-v1-0-12/14/04-16:49:32) 
and the echo is still there.

A support guy at Digium said it was a SIP problem.

What can I do to track down and fix the issue?

Thanks in advance,
Brian

>From sip.conf...
[89XX-1]
type=friend
host=dynamic
secret=89XX-1
context=local
callerid="NAMEXX" <859-392-89XX>
disallow=all
allow=ulaw
qualify=yes

>From zapata.conf...
[channels]
echocancel=yes
echocancelwhenbridged=yes
echotraining=yes
rxgain=0.0
txgain=0.0
switchtype=national
signalling=pri_cpe
context=incoming
group=1
channel => 1-23
signalling=fxo_ks
context=longdistance
group=2
channel => 25-28