[asterisk-dev] Queries regarding Echo Cancellation in Zaptel-1.2.6

[Steven]

On Mon, 2006-07-17 at 17:04 +0800, Chan Kwang Mien wrote:
> Hi Paul,
> 
> Thanks for your reply. 
> 
> The purpose of my tests is to verify that Echo Cancellation is up and
> running in the zaptel-1.2.6 that I have installed. 
> 
> In my test-bed, 
> 
> IP Phone A <------> Asterisk IP PBX <---> Analog Phone B

Hopefully to put one more explination out here to make sure it is well
known why your problem isn't one that is solveable in Asterisk.

Take your example above and break it down the way asterisk will see it.

IP phone <-----> Asterisk 

IP phones are 4 wire equivalent so no echo should be introduced here. No
echo cancellation is needed

Analog Phone <---- Asterisk

Asterisk monitors this to gather data for echo cancel.

Asterisk ----> Analog Phone

Now asterisk knows what it sent and can try to remove it from the
returning audio stream. 
 
-- 
Steven <critch at basesys.com>