[asterisk-users] Seeking advice about ISDN BRI Cards

[jg]

> Thank you all for valuable input,
>
> another question: when do I actually need the echo cancellation
> (hardware / on board /on module ) ?
>
It depends on your environment. If there are still analog devices in addition to VoIP, I'd say 
always, but Asterisk has a rudimentary echo canceller already on board. The Telcos use echo 
cancellers themselves, but it cannot hurt to have a hardware canceller on your BRI card.

Nowadays I see more problems with reverberation in connection with cheap speakerphones or simple 
mics and speakers on PCs, but that's a different story.

jh