Path: utzoo!utgpu!watserv1!maytag!xenitec!zswamp!root
From: root@zswamp.uucp (Geoffrey Welsh)
Newsgroups: comp.dcom.modems
Subject: Re: Hayes announces Ultra 144 and V.32bis upgrade
Message-ID: <270.286C060A@zswamp.uucp>
Date: Fri, 28 Jun 91 12:15:17 EDT
Organization: Izot's Swamp BBS (FidoNet), Kitchener, Ontario

In a letter to All, Kurt Sletterdahl (kurt@pnet51.orb.mn.org ) wrote:

 >Pardon my dumbness, but why don't V.32bis modems have a DTE 
 >interface speed of 57,600bps?

   I can think of two reasons right off the bat, and I'm not at all involved 
in the development of modems:

(1) You'd be surprised how many systems either don't support high baud rates 
over async RS-232 ports or don't do so reliably.  There are still some 
operating systems and/or serial cards that don't normally go higher than 
19,200!

   I'm not sure how standard 57,600 bps is; it's certainly convenient for a 
normally configured 8250-type chip, but it's 3 times 19,200... an odd number 
(no pun intended) for an increase in RS-232 speed!

(2) I advise all of my clients to send all data in compressed format, so 
V.42bis has little or no influence on the throughput.  Since V.32bis has a raw 
data rate of 14,400 bps and LAP-M strips async framing, 19,200 bps is just 
fast enough to get maximum throughput on a compressed file.
 

--  
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