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> <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.