[Asterisk-Users] Echo cancellation, when software doesn't cut it. Whats next?

[Andrew Kohlsmith]

On Thursday 01 July 2004 08:39, Robinson Tim-W10277 wrote:
> All voip providers will use digital 4-wire interconnect to Asterisk or
> similar, so echo problems are much reduced, as there are only 'echo
> points' at the far end and your handset.

And on my PRI that is specifically where my echo is coming from... the far 
end.

VOIP calls through nufone have no echo
MOST PSTN calls through the PRI have no echo
SOME PSTN calls (usually to local numbers NOT terminated at my local CO) have 
significant echo...  I too have been unsuccessful in getting this zapped.

My connection:

Norstart MICS <--> Adit600 <---> T100P <-- IAX2 <--> TE405P <--> Bell Canada 
PRI

*1 = Xeon/2.4 with HT with T100P
*2 = Xeon/2.4 with HT with TE405P

*2 also does the NuFone IAX2 connection (it is always in the loop, as *1 is on 
a private network)

Strange stuff, I am going to look at T1 echo cancellation hardware if I cant' 
get this solved.

Tried:
- echotraining=800 on *1 and *2
- echocancel=32,64,128 on both

Eventually the MICS will have a digital connection to *1 instead of going 
through the Adit600 but we haven't got there yet :-)

Regards,
Andrew