Hi,
I’m quite new to Asterisk. I’ve setup a server with Asterisk 1.4, an OpenVox B100P ISDN 1xBRI PCI card and four SNOM M3 DECT/SIP phones.
In some cases, I can hear my own voice while I talk with someone. The sound quality is very good except for that.
I’m under the impression that echo shouldn’t occur when using ISDN cards/lines. Am I wrong?
What could be the problem here? The card? My settings? The SNOM phones? I must mention that echo may occur or not while talking with the same person, using the same handset, over the same lines etc, so I don’t think it’s a hardware issue… but then again, what do I know? 
I’d appreciate any help or pointers,
Thanx in advance