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From: root@zswamp.uucp (Geoffrey Welsh)
Newsgroups: comp.dcom.modems
Subject: SO...On average, what kind of throughput will I get on Compressed Files
Message-ID: <154.284B10AF@zswamp.uucp>
Date: 3 Jun 91 21:37:01 GMT
Organization: Izot's Swamp BBS (FidoNet), Kitchener, Ontario
Lines: 35

In a letter to All, Robert D. Thompson (rdthomps@vela.acs.oakland.edu ) wrote:

 >What kind of throughput can one expect on compressed
 >files over V.32bis ?

   That depends on protocol; streaming protocols like ZMODEM or YMODEM-G 
should give 1750 CPS or so unless you're calling a modem that doesn't support 
V.42 or MNP (which isn't all that common these days).

 >From the discussions, I gather that it does not 
 >degrade below 9600 because of error-correction, flow, etc...

   I can't for the life of me guess what that means.

 >I also gather that it does not take advantage of 
 >compression, and thus does not exceed 9600 ?

   Perhaps the most important thing that a reader can learn from this 
conference is that data compression has absolutely nothing to do with the 
modulation protocol.  V.32bis is a modulation protocol (it describes how bits 
are converted into signals for the phone line, and nothing more), and it does 
not include data compression... but neither does any other modulation 
standard.  You follow?

 >So...will compressed (or randome) files pretty much 
 >stay at 9600 baud throughput ?

   They'd better not, since V.32bis is a 14,400 bps modulation protocol.
 

--  
Geoffrey Welsh - Operator, Izot's Swamp BBS (FidoNet 1:221/171)
root@zswamp.uucp or ..uunet!watmath!xenitec!zswamp!root
602-66 Mooregate Crescent, Kitchener, ON, N2M 5E6 Canada (519)741-9553
"He who claims to know everything can't possibly know much" -me