On 11 Jun 96 at 18:28, Brian Elfert wrote:
>
>
> > actually... the best thing they could do is to offer v.34 "digital
> > modems"... they will be upgradeable to 33.6 etc etc that way... a source
> > said that the new box they are throwing out has a 486-66 and a digital
> > modem solution. it will also handle one or two PRI and modems on all
> > channels and not just 3/4's of the channels like some current solutions...
> > it should also be the sizeish of an irx... how's that for port density...
>
> Well, if they OEMed USR modems, they have flash ROM and they already
> support 33.6. I guess I'm not sure what the difference between a digital
> modem and one with flashable DSP and ROM is.
A real digital modem is a modem which allows direct access to the DSP
(digital signal processors) from the line interface. Of course this
line interface has to be digital; a BRI connection or one B-channel
of a PRI.
To clearify: USR does exactly this with the Total Control System: if
you have a T1 or PRI card, the digital data on the B-channel for
analog calls (3.1 khz speech) is directly transmitted to the DSPs of
the modems.
Manufacturers like Ascend first convert the digital signal from the
B-channel to analog data (a/b interface), transfer it to the modem
part which then converts the analog signal to digital adat to supply
this to the chipset (mostly Rockwell stuff). This is shit.
Say MZ, Livingston will do the digital thing, right? (I'm pretty sure
they will...)
Frank
-- ***** The expressed opinions are totally mine! ***** Frank M. Heinzius MMS Communication GmbH frimp@mms.de Eiffestrasse 598 http://www.mms.de 20537 Hamburg, Germany Phone: +49 40 211105-0 Fax: +49 40 210 32 210 ***** U.S.Robotics and Livingston Distributor *****