[Asterisk-Users] echo / delay problem

[C F]

> > [channels]
> > echocancel            = 16
> > echocancelwhenbridged = yes
> > echotraining          = no  ;; yes
> > rxgain                = -2.0
> > txgain                = -2.0
> 
> If you are in the US and using a digium x100p, then try the following:
>  echotraining=800
>  echocancel=yes
> (The values you are showing above aren't even valid parameters.)

Why not? I don't see what wrong with those values? Can you explain please?