Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!wuarchive!udel!burdvax!gvlv2!faatcrl!jimb
From: jimb@faatcrl.UUCP (Jim Burwell)
Newsgroups: comp.dcom.modems
Subject: Re: Summary: Do T2500 using V.32 talk to anything else.
Message-ID: <1098@faatcrl.UUCP>
Date: 26 Nov 89 03:45:10 GMT
References: <1074@kimbal.lynn.ma.us> <10336@attctc.Dallas.TX.US>
Distribution: na
Organization: FAA Technical Center, Atlantic City NJ
Lines: 47

chasm@attctc.Dallas.TX.US (Charles Marslett) writes:

>In article <1074@kimbal.lynn.ma.us>, rick@kimbal.lynn.ma.us (Rick Kimball) writes:
>[Summary omitted.]
>> Thanks to the following people for responding:
>> 	casey%gauss.llnl.gov@lll-crg.llnl.gov (Casey Leedom)
>> 	faatcrl!jimb@gvlv2.gvl.unisys.com (Jim Burwell)
>> 	"Mark Solsman" <MHS108@PSUVM.PSU.EDU>
>> 	Mark A. Verber <verber@pacific.mps.ohio-state.edu>
>> 	cca.ucsf.edu!wet!tempest@cgl.ucsf.edu
>> 
>> Rick Kimball              INTERNET: rick@kimbal.lynn.ma.us
>>                               UUCP: ...!spdcc!kimbal!rick, ...!spt!kimbal!rick
>> Personal USENET Site          POTS: (617) 599-8864
>[Most of article omitted.]

Rick said:
>> | Will [V.32] be superseded by something else.
>> 

Then I said:
>> It already is.  V.42 is out.  USR HST DS users will have chip upgrades RSN.
>> Telebit T2500 users will also get V.42 chips with the next ROM releases.

Then you asked:
>Isn't V.42 just another data compression/error correction standard?  Not really
>superceding V.32, but just replacing (or coordinating with) MNP4 and 5?  I 
>thought it was a standard for end-to-end error correction protocols.  Wrong?

>That is, doesn't it really replace MNP4 (or whatever) with a slightly more
>comprehensive scheme which includes the MNP protocol?

I don't have any technical specs in front of me, but someone told me that V.42
was a new modem to modem protocol, which combined "lapb/lapm, trellis encoding"
etc etc.  (Byte wrote a good article on all this stuff a while back).  As far
as I know, MNP just sits on top of a underlying low-level protocol, or modem
engine.  Adding a higher MNP level (I think it goes up to 9) wouldn't change
the CCITT spec, I would think.  Someone else told me that V.42 was simply the
protocol which Hayes uses in it's V-series modems.  Anyway, as far as I know,
it will be better than V.32, and HSTs and T2500s, and many other modems will
support it...

BTW:  for the person who asked, Telebit IS coming out with V.42 roms RSN.
I read it in a letter which Telebit sent with its latest upgrade roms..

Bye
Jim


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