[Asterisk-Users] Re: Echo Training Question From a Newbie

[Stephen R. Besch]

> 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.

Well, yes and no. For many of us, the wire run to the telco's digitizer 
is rather consistent. Even in cases where consistency is a problem, as 
long as the delay line tap wights were stored on a per-FXO basis, it 
would make a better starting point for the echo training than some 
arbitary set of weights (like all 1's for instance), especially since 
the echo canceller trains constantly anyway. In theory it would speed up 
the initial training.  This would be a particularly useful option to 
have for those of us with highly consistent line conditions.

Stephen R. Besch