[Asterisk-Users] Channel Bank Echo

[Peter Svensson]

On Sat, 29 Jan 2005, Matt Schulte wrote:

> Agh, what I meant was the echo is heard from the PSTN side. It seems
> echo canceling on the T1 (going to channelbank) does nothing, I'm
> assuming because the T1 is "digital" and the channelbank is the
> traversal from digital to analog.

Still, echo cancelling on the T1 should solve the problem since it is on 
the digital path from the echo source (the hybrids on the channel bank and 
on the phone) to the pstn.

Perhaps your channel bank is set to the wrong impedance compared to the
hybrid in the phone? That can cause an echo more powerful than the cho
canceler is designed to handle.

You need to set "echocancelwhenbridged=yes" in the zapata.conf for 
asterisk to even attempt to cancel echo between two digital links.

Peter