[mod.telecom] High-speed modem query

pjatter@SANDIA-CAD.ARPA (10/21/85)

We are currently evaluating high-speed (i.e., > 1200 baud) modems to
link our remote terminal users to our Vax.

There seem to be plenty of options in the 2400 baud arena, but now
we're getting greedy and are looking at some of the 9600 baud modems
which are beginning to become available. Does anyone have any
experience with 9600 baud modems (preferrably asynchronous)?  The only
companies I've seen advertise so far are:

 Electronic Vaults (Reston, VA): upta 96 (asynchronous)
 Universal Data Systems (Huntsville, AL): UDS 9600 A/B (synchronous)

(We just obtained a UDS modem for evaluation (using their EC-100
synchronous -> asynchronous converter) and had no trouble getting it
to work here in the office.  We haven't tried it over long distance
lines yet.)

It appears that there are some proposed standards for these modems
(CCITT V.29 & V.32).  I've seen some proposed CCITT standards (V.29 &
V.32) mentioned in the literature for these modems. Does anyone know
just what these standards standardize?

Paul Attermeier
Sandia National Labs
Div 5324
Albuquerque, NM
UUCP: ...{ucbvax | ihnp4!lanl | gatech}!unmvax!sandia!pjatter
ARPANET: rowe@sandia-cad

bobh@pedsgd.UUCP (10/24/85)

In article <120@sandia.UUCP> pjatter@sandia.UUCP writes:
>We are currently evaluating high-speed (i.e., > 1200 baud) modems
>to link our remote terminal users to our Vax.
>
>There seem to be plenty of options in the 2400 baud arena, but now
>we're getting greedy and are looking at some of the 9600 baud
>modems which are beginning to become available. Does anyone have
>any experience with 9600 baud modems (preferrably asynchronous)?
>The only companies I've seen advertise so far are:
>
> Electronic Vaults (Reston, VA): upta 96 (asynchronous)
> Universal Data Systems (Huntsville, AL): UDS 9600 A/B (synchronous)

Another option which just arrived is the Telebit modem, being marketed
by Digital Communications Associates (PC Irma coax interface board et
al).  This is a proprietary asynch scheme for 9600 b/s which
purportedly can adapt to changing line conditions on the fly in
increments of <100 b/s.  They do this by subdividing the bandwidth
into numerous subchannels to spread out the information.  I seem to
recall price for the stand-alone unit to be about $2400.  I mention
this since, as they are currently selling for the volume PC
marketplace, they are likely to become a de facto standard.  I believe
the information number is 1(800) TELEBIT.

						Bob Halloran
						Sr MTS, Perkin-Elmer DSG
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