[Asterisk-Users] Echo Training Question From a Newbie

[Anon]

On Monday 26 April 2004 04:53 pm, Kevin Williams wrote:
> I'm running CVS code from about a week or so ago.  We've been having
> echo problems on outbound calls to the PSTN, so this weekend I enabled
> the echotraining flag in my zapata.conf.  This works great - after the
> first 3 or 4 seconds of the call.  Those first few seconds have terrible
> echo however.
>
> I was expecting the system to remember its "training" between calls - is
> there some additional configuration flag I need to enable that?  Or is
> there something more I need to do?
>
> Also, I read that there are alternative echo cancellation algorithms
> available - but I haven't seen a way to specify which one should be used...
>
> Thanks!

As I understand it, there are many characteristics of the PSTN line that are 
continuously changing.  That is the reason Asterisk "trains" on each call.  
If Asterisk did not train on each call, we would regularly get less than 
optimal results for echo cancellation.  Be sure to see the Wikki about echo 
cancellation:
http://www.voip-info.org/tiki-index.php?page=Asterisk%20x100p%20echotraining

Anon