[Asterisk-Users] Modem cards??

[Steven Critchfield]

On Thu, 2003-11-27 at 13:39, Andrew Nelson wrote:
> --On Wednesday, November 26, 2003 9:03 PM +0500 wasim at convergence.com.pk 
> wrote:
> > On Wed, 26 Nov 2003, Angel Gabriel wrote:
> >> I've just been informed, in an IRC room, that it is possible to use a
> >> modem card with *.  Can someon please confirm this for me? Thanks in
> >> advance.
> >
> > why don't you also mention that after being informed of this, about 10
> > different people also told you it wouldn't work and to just go ahead and
> > by an X100P ?
> 
> Ok if standard voice modmes do not work with Asterisk as an FXO then why 
> does the X100P look an awful lot like the AMI-IA-96 modem?  In fact why do 
> they even have the same FCC ID numbers?  I have no problems with supporting 
> Digium by purchasing their hardware, but what makes this modem more equal 
> than others?

Because modem drivers do not allow full duplex sound. This is a
limitation of the interface chosen by the implementers of the
specification. I'd about lay money they did this to not cannibalize
their higher profit telephony card market. 

In the case of Digium's card, they wrote a driver that no longer
contains any protected(patented) code for modems, and just exposed the
audio in both direction and the telephony sensing. This allows them to
bypass large chunks of code that would sit dormant and just be in the
way of the asterisk system.

So the extra you pay is in part helping Digium repay their development
costs up to this point, both in the driver and in the application. The
other part you are paying for is 1 hour of support from Digium, and a
bit of a free pass from being flamed on this list for scabbing parts.

So please support Digium and their fine network of resellers by buying
parts from the authorized channels. The alternative may be cheaper on
the wallet, but not on your soul.   
-- 
Steven Critchfield <critch at basesys.com>