[Asterisk-Users] One way echo canceling?

[Doug Lytle]

Hey everybody,

I have a situation where we have 2 Asterisk (CVS as of 08/25/2005) 
connected via IAX.  On the corporate side, we have 1 TE110P connecting 
to a Definity G3R and it's connecting to a TN464F card, giving a 23 
channel connection.  I have echocancel=yes, echotraining=yes and 
echocancelwhenbridged=yes.

One the remote office side, they a Adit 600 channel bank for 10 outside 
lines and is using a Point to Point T1 for communications between divisions.

When there is a call on zap 1, from a sip phone on the remote office 
side and typing 'zap show channel 1'  shows echo cancel is on, doing the 
same thing from the Definity to a SIP phone shows echo cancel off.  
Shouldn't it be on during a call on both the incoming and outgoing legs 
as long as it comes accross the PRI?  Some (Myself included) have noted 
a slight echo on the Definity to SIP leg of the connection.

My zapata.conf is below:

switchtype = national
context = incoming
signalling = pri_cpe
echocancel=yes
echotraining = yes
echocancelwhenbridged=yes
overlapdial = yes
group = 1
channel => 1-23

All suggestions would be welcome.

Thanks!

Doug