D'apres David Floyd <david@floyd.org.uk>,
dans le forum uk.telecom.voip...

> >Did you adjust the line impedance settings ? Both for FXO and FXS ?

> Yes, but if you read other posts on this subject in the past as I have
> now done, this is a known problem with making PSTN calls on a SPA3K

That's right, but having good settings helps the echo canceller
operation, thus reducing (even if not totally eliminating) the
perceivable echo.