[Asterisk-Users] Scaleable Solution for small office

[TC]

>I would like to upgrade to a channel bank, and was wondering if anyone has
had any echo issues with other >digium hardware.
the t100 connected to a channel bank will not gurantee no echo,
but from experience I do have 2 solutions that removed 100% of the echo from
my installations


1) CAC ADIT 600 channel bank, 8 port FXO cards with what CAC call adaptive
impedance matching
     I had both a x100 and a t100 and an adtran ta-750 that both produce
echo connect to my local PSTN
     when i tried the ADIT 600 with 8 port FXO connect to my analog line ALL
perceived echo
     vanished, I still had the echo can settings in zaptel turned on

2) Install an Inline T1 hardware echo can between the T100 card and the
channel bank T1 interface
    I took that same adtran ta-750 that gave echo on the analog lines and
installed a TellLabs 2572 64ms
    hardware echo card, turned off all zaptel echo settings, and All
perceived echo vanished

My personal belief is that the hit and mis echo on the x100/x101 cards is
caused by the impedance mismatch
between these cards and different Telco lines, the zaptel stuff tries to fix
this echo after the
fact & the current algorithms will not converge in a sub-second time frame