[Asterisk-Users] echo cancellation on an iax2 channel

[Steve Underwood]

Script Head wrote:

>I have minor echo on an IAX2 channel when using Firefly and a head
>set. I have tried various headsets and settings but still a little bit
>of the echo remains and I'd love to get rid of it. After some research
>I stubled on zaptel/mec2.h but it seem that it works only on the ZAP
>channel. Is there something I can do on the IAX2 channel?
>  
>
Basically no. You cannot apply echo cancellation to a VoIP path. The 
path length needs to be precisely constant for the algorithms to work. 
That cannot be guaranteed over a VoIP path. A VoIP phone (hard or soft) 
needs to remove the echo at source. Good ones do. Bad ones, including 
some expensive ones, do not.

Regards,
Steve