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From: jjj@blob.hut.fi (Joni Jaakko J{rvenkyl{)
Newsgroups: comp.dcom.modems
Subject: Re: USR 9600 baud dual standard - V.42bis throughput
Message-ID: <1990Oct7.211433.21894@santra.uucp>
Date: 7 Oct 90 21:14:33 GMT
References: <1990Sep30.024433.28717@athena.mit.edu> <1990Sep30.171414.5132@nstar.uucp> <1990Oct1.175833.28288@athena.mit.edu> <1990Oct2.092 <1990Oct06.145608.15322@scuzzy.in-berlin.de>
Sender: news@santra.uucp (Cnews - USENET news system)
Reply-To: jjj@niksula.hut.fi (Joni Jaakko J{rvenkyl{)
Organization: Helsinki University of Technology, Finland
Lines: 23

In article <1990Oct06.145608.15322@scuzzy.in-berlin.de> src@scuzzy.in-berlin.de (Heiko Blume) writes:
>a question, while i'm at it: is V.42bis asymmetric like the HST protocol
>(with a slow backchannel) ?? theres nothing about it in the manual.

V.42bis has nothing to do with the data transmission technique, it is a data
compression standard ONLY.

So, you now have the good old HST with the V.42bis which tries to compress
the data being sent. What comes to sending precompressed data, the V.42bis
has the ability to turn itself off if there's nothing much to compress.
1600-1700 cps throughputs are usual with even a normal HST (read: with MNP5)
with compression disabled (&K0) when sending f ex .ZIP files.

If you don't believe me, get a HST with MNP5, and then download a
precompressed file with the MNP5 compression on. Then put the compression
off and try again. You'll be surprised to get better throughput with the
compression off.

--
jjj@niksula.hut.fi
jjj@otax.tky.hut.fi

fire me, fire					until you die