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Path: utzoo!watmath!clyde!burl!ulysses!allegra!mit-eddie!genrad!decvax!mcnc!unccvax!dsi
From: dsi@unccvax.UUCP (Dataspan Inc)
Newsgroups: net.dcom
Subject: Re: Experience with 9600 bps on Dialup
Message-ID: <135@unccvax.UUCP>
Date: Mon, 11-Feb-85 19:06:35 EST
Article-I.D.: unccvax.135
Posted: Mon Feb 11 19:06:35 1985
Date-Received: Thu, 14-Feb-85 01:42:49 EST
References: <266@ttidcb.UUCP>, <550@vortex.UUCP>
Organization: UNC-Charlotte
Lines: 28


     One of the major modem manufacturers (UDS) have a facility whereby
you can dial a number in a distant city, dial a second number in same
distant city, and have the two connect. These were in place in several
major markets, and were used presumably by UDS to do real world testing
for the 9600 A/B. 

     Has anyone been able to confirm the effects of SLIC compressors and/or
noise gates on the 9600 A/B? We were having one heck of a time in the 662 
exchange at Buffalo, NY. When the lines were requested with RJ-45S jacks,
the "effect" that was munging the training burst magically went away. Several
other circuits which are "normal" still fail to work correctly. 

    The effect was that the first part of the training burst was being cut
off by something like an expander with a very long attack time. In fact, if
you wrote software to take DTR high, low, then high again, the faulty 
circuits would then work about 50 $% of the time. (high=assert, low = negate..
no flames please)

     What was * REALLY * funky about this compression business was that
within Orchard Park, nothing would ever work at all. When dialing from 
or into Orchard Park via long distance from about 10 major American cities,
the equipment worked perfectly. Where would such a noise gate or other
device be located ?

dya
/