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

[karl at streetlampsoftware.com]

Jenny -

I'm glad I'm not the only one! I just installed Asterisk on Friday and I
spent all day trying to de-gremlin my system. I'm glad I'm doing it for
myself and we haven't switched from our legacy system yet, but I have a
potential client that wants to see how well I can implement this system
for myself...

(Speaking of which, don't forget that your supplier and consultant
probably make more off of other phone systems and a lot of old-line
suppliers are kind of afraid of Asterisk. There were some big companies
that lost out when the State of Oregon's court system went to Asterisk for
their teleconferencing needs... 600 MeetMe sessions a day does say
something, I think.)

First, it would help -me- to know precisely what hardware you're using
(including network... switches and cards) and what phones you're using.
You can email me off-list if you want.

I'm personally using a AMD Sempron-based system with a TDM-04B (4x FXO) in
it, routing out through an IntelPro 10/100 card. The data switch is
currently a crappy D-Link, but more on that and the network card in a
second. The other end is one soft phone on Linux and two SPA-841 hardware
phones.

When I first installed, the echo was terrible. Tweaking around with the
echo settings in zapata.conf endlessly didn't do a whole lot. So, using my
go-go-gadget troubleshooting instincts (and my handy-dandy go-go-gadget
credit card) I figured the problem might be network latency ... so I
replaced the crappy realtek network card with a high-quality Intel one,
and borrwed a Dell managed switch from a client for the day. Voila, a few
more tweaks to the echo learning rate and my echo problems went away, and
I spent 45 minutes learning about my sister's love life in the wilds of
downtown San Francisco. (Note to self: Don't use family to test telecom
systems.) The clicking persisted, though. I thought it was the phone at
first, but if you're experiencing it too... well, apparently it's not.

I searched the archives and couldn't find any other reference to clicking
noises, so I'm at a loss but I'm hoping it's wiring-based and heading back
to the office tomorrow to try and solve it. I think you're right that
Digium is focusing on their T-1/E-1 market. I've noticed it when I called
with a question, and that really ticks me off. It might be a decent, sound
business decision based on profits for the different cards, but it's
leaving a lot of us smaller business operators -- those who might take
great experiences with Digium and Asterisk products into potential large
customers -- swinging in the wind.

-Karl Katzke
Streetlamp Software Solutions
http://www.streetlampsoftware.com


> 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
>
>
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