I was using FreeBSD-7.1 with Asterisk-220.127.116.11 with Zaptel-1.4.6. That was working well but then the porters at FreeBSD decided to remove the wcfxo module from the latest port for zaptel which rendered my X101P card useless. So I rebuilt a new drive using Fedora-10, Asterisk-1.6.4, and Dahdi-2.0.1. The system seem to work just great until I tried to make calls with my SIP phones. The echo was overpowering. I put the old drive back in with the older version of * and zaptel and the phones worked without echoing.
So my question is this: Does Dahdi not have the same echo cancellation features as zaptel and why does the zaptel cancellation work but Dahdi does not?
My dahdi conf files included the echo cancellation lines.