[Asterisk-Users] Small office setup/using analog lines w/ Asterisk

[jennyw]

Hi,

We recently tried installing Asterisk for a small office. We figured the 
safest way to go would be to buy from someone who sold equipment 
specifically for Asterisk and to use a consultant that they 
recommended.  However ... it didn't turn out so great.  Sound quality is 
terrible -- the echo is pretty bad, and there are popping noises, too. 
Callers say that people on the Asterisk end sound very faint, while 
people on the Asterisk end hear people maybe too loundly (might be 
related to the popping noises -- sounds like when you have stereo turned 
up too high).  The reseller and the consultant both say that the most 
likely cause for this is using Digium cards w/ analog phone lines. 
Apparently, they say, sound quality can be pretty bad.

I called Digium and they gave me some suggestions for settings, but 
nothing has worked well. So I wanted to ask others ... has anyone had 
good luck with using analog phone lines and Asterisk? Especially with 
Digium cards (we use the TDM400P)? Although from reading articles on the 
net it sounds like people do have a lot of echo problems, it also sounds 
like some people are using analog phone lines with some success.

FYI, what I've mainly done is try changing echotraining, echocancel, 
echocancelwhenbridged, txgain, and rxgain in zapata.conf. I've heard 
from the reseller that what might work better is to trade the Digium 
cards in for VegaStream gateway. It's more expensive, but apparently has 
a DSP built in that should increase voice quality. Of course, they say 
there are no guarantees with this.  They also mentioned (after the fact) 
that Asterisk systems don't necessarily save money. So far, the 
experience has been very frustrating and I'd love to hear some success 
stories from others (or more info on what I can realistically expect 
from an Asterisk system)! And, of course, some ideas on how I can get 
things to work better.

One of the next tests will be using Asterisk with a VoIP provider to see 
what the sound quality is like with digital on both ends. PRI sounds 
like it'd be even better, but for an office w/ 5 people, it sounds 
pretty expensive. How do other people do this?

Thanks in advance for any pointers!

Jen