Newsgroups: comp.dcom.modems
Path: utzoo!utgpu!jarvis.csri.toronto.edu!csri.toronto.edu!ray
From: ray@csri.toronto.edu (Raymond Allen)
Subject: Re: V.42 [was: Telebit in Byte's test, Ventel PEP, V.32]
Illegal-Object: Bad Keywords value found by ZMailer on jarvis.csri.toronto.edu:
	V(?illegal word in phrase?) . 42 ;
Message-ID: <8808251940.AA00343@ellesmere.csri.toronto.edu>
Keywords: error correction / data compression, standards, PEP, MNP, V.42
Organization: University of Toronto, CSRI
References: <1313@neoucom.UUCP> <5916@bigtex.uucp> <Aug.12.14.09.59.1988.16394@topaz.rutgers.edu> <6069@bigtex.uucp> <8808162000.AA04427@yorkville.csri.toronto.edu> <15303@shemp.CS.UCLA.EDU>
Date: Thu, 25 Aug 88 14:20:19 EDT

In article <15303@shemp.CS.UCLA.EDU> casey@cs.ucla.edu.UUCP (Casey Leedom) writes:
>  Standards are hard enough to get everyone to agree on that it makes
>sense to design extensible ones that can grow with technology.  Don't you
>think we've had enough standards that tie our hands as better technology
>comes along?
>
>  Standards can be wonderful things, but when they're blindly applied
>with no thought to the future they become mill stones in a very short
>time.
>
>Casey

Actually, V.42 does contain much room for adding future error correction
and/or data compression methods.  But your point is well taken.  It is worth
noting, however, that many of the industries' largest modem mfrs. have
worked together (and sometimes *not* together from my understanding) to
make V.42 what it is today.

With regards to your point about blind application, it is worth noting that
provision for the use of a 32-bit CRC (CCITT calls it
the "Frame Check Sequence") was added to the V.42 specification.  This is nice
from a technological standpoint since it will reduce the bit error rate to
about 10e-239 (note: :-) ) but from an implementation standpoint it is a real
b**ch because there is hardware in existence that will calculate the 16-bit
CRC but the 32-bit one would have to be done in software and this has to
be done for each character transmitted -- a rather large overhead.
Seems that (as usual) standards committies have reduced awareness of real-
world considerations.
-- 
Ray Allen  | Someday I'm going to have to change my .signature.
utcsri!ray | All of the above is usually my own opinion.

