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

[Kris Boutilier]

> -----Original Message-----
> From: TC [mailto:trclark at shaw.ca]
> Sent: October 12, 2004 11:06 AM
> To: Asterisk Users Mailing List - Non-Commercial Discussion
> Subject: Re: [Asterisk-Users] Chaining more than one zap echo 
> canceller?
> 
> 
> - I am very close to my serving CO which brings the line down to about
> 150ohms and the channel bank is expecting 600ohms.
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> where/how did you measure this ?

This was measured out of the distribution frame at the CO by a telco cable
technician.

> >  So, I have a fix for the sidetone/impedance problem (PRI on order)
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> 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 ?

We have both overline and DID facilities that we are consolidating onto the
PRI. Combined with the addition of CallerID services, the ability to
reassign existing analog numbers as DID numbers and our contract discounts
it works out economical for us to implement as 11B+D at this site. The costs
for adding facilities later are pretty scary though.

For those who may be interested prices for all of Telus offerings can be
gleaned from their tariff documents at:
http://about.telus.com/cgi-bin/tariffs.cgi

> > 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

I think I'm going to end up going down this road also as I have other sites
where PRI would not be economical at all.