[asterisk-users] Modem

[Jared Smith]

On Sun, 2009-08-02 at 14:54 -0400, Carlos Ruiz Diaz wrote:
> Why  PC modems were not used as FXO devices? Why chan_modem was
> deprecated? it seemed a nicer option instead of buying expensive
> gateways.

This question has been answered many times, but just for the fun of it
I'll answer it again:

If PC modems had been ideal telephony cards, we'd still be using them.

My own experience with using modems as FXO devices (long before I became
a Digium employee) was that they were awful.  I encountered problems
with echo, half-duplex audio, and lack of far-end disconnect
supervision.  All of those problems are solved with most modern
telelphony cards (except for the ultra-cheap cards, which are still just
modems).  To put it frankly, I wouldn't wish one of those modems on my
worst enemies.

> Anyway, for people living really far from USA the price gets
> incremented twice or more and this is without considering the
> conversion between currencies. 
> 
> 1 $ = 5100 Gs., not cheap at all.

I understand that the cards are disproportionately expensive in many
parts of the world as compared to the United States, because of the
difference in economies. I spent a couple of years in Paraguay in the
mid 90s, and know what it's like to pay outrageous prices for
specialized electronics just because they have to be imported from other
countries. (I'm guessing that you're from Paraguay, based on on the
monetary conversion you gave.  Does Antelco still dominate the telco
market in Paraguay, I wonder?)

That being said, the cost per port of the Digium cards (or any of our
competitors who design their own cards) is still much lower than what
you'd pay for traditional telephony cards, such as those manufactured by
Dialogic or Aculab.

I know that probably doesn't help you afford to be able to buy a more
expensive card, but hopefully you have a better understanding of why we
don't use modems as FXO devices.  If your time and sanity are worth
anything at all, it's a worthwhile investment to buy a good solid
telephony card.

-- 
Jared Smith
Training Manager
Digium, Inc.