I’m trying to set up a system based on Asterisk 126.96.36.199 and DAHDI 2.2.0. Try as I might, I just can’t seem to find the right combination of echo canceller settings. I am using a TDM410 with a single FXO port.
I have a second Asterisk machine here which uses a TDM400 card and the old Zaptel drivers. Simply setting ‘echocancel=yes’ and ‘echotraining=yes’ in zapata.conf was sufficient to get no discernable echo on my BT line (in the UK).
Using exactly the same line and wiring, I should reasonably expect to be able to get the performance of my newer DAHDI based system to match, am I right? Problem is - it doesn’t. There is considerably more echo on the DAHDI system than on the Zaptel one.
I have run fxotune and it’s spat out “4=5,0,0,0,0,0,0,0,0”.
I have tried the MG2, KB1 and SEC2 echo cancellers. At the moment I’ve got the best results I can with the KB1 canceller and the following settings in chan_dahdi.conf:
Does anyone know what the equivalent settings are in the various DAHDI options to cause the echo canceller to behave as the default on in the Zaptel drivers?
And has anyone had any eureka moments and can post a ‘magic’ set of settings that actually cancels the echo?
Would a hardware echo canceller be that much better? Seeing as I don’t have one on my Zaptel system I don’t really see why I should need to pay for one on the DAHDI system.
Any help appreciated. Giles.