[Asterisk-Users] Chaining more than one zap echo canceller?

[TC]

> I have Asterisk connected to a channel bank via a t100p card. There
> excessive sidetone generated on the analog side due to an impedance
mismatch
> - I am very close to my serving CO which brings the line down to about
> 150ohms and the channel bank is expecting 600ohms.
where/how did you measure this ?
> However, the very loud
> sidetone is being fairly effectively supressed by the zap echo canceller
and
> I have quite usable lines as a result.
>
>  From time to time calls are placed to other PSTN numbers (even
terminating
> off of the same CO) that are introducing their own far end echo component
on
> the line and it isn't being supressed at all - thus my outbound callers
> begin to hear their own voice and get very frustrated. I have to assume
the
> second reflection couldn't be supressed by design - the zap echo can has
> already locked on to the sidetone echo after all.
>
>  So, I have a fix for the sidetone/impedance problem (PRI on order)
however
heh looks like your in BC, is replacing with  a pri cost effective in my
calc's
here the break pt is usually about 16-18 analog lines ?
> is it possible to insert another can into the system somehow?
some of us that have been around the block a few times with this fscking
echo echo echo
have ended up buying an inline hardware echo can between the T1xx/T4xx
and the channel bank then turn off all echo cans in asterisk
i have used the Tellab 2572 64ms and have crystal clear sound others report
the same
google for some other brands other have used ...
(its prolly more cost effective that buying the PRI here in BC as well :)