[asterisk-users] [Zaptel] Why no driver for PCI voice modems?

[Andrew Kohlsmith (lists)]

On April 1, 2009 01:32:18 pm Jason Aarons (US) wrote:
> I don't think a off the shelf modem has the necessary DSPs to convert
> voice to codec....that is why a Voice Gateway/Analog Telephony Adapter
> or FXO/FXS cards exist instead of modem having a second life.

There are no DSPs in any of the telephony products you get from Digium, 
Sangoma, etc., with the exception of the VPM (echo cancellation) add-on 
modules and some minor hardware assistance that hardware that the digital 
span cards provide.

In fact, that was the entire point made by Zaptel and also by projects such as 
SpanDSP -- you don't need a fancy DSP to do mid-scale voice processing on the 
computers of the day, and processing power is only increasing.

-A.