Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!ucsd!ogicse!blake!milton!amigo
From: amigo@milton.acs.washington.edu (Michael Robertson)
Newsgroups: comp.dcom.modems
Subject: Re: v.42? v.32? v.va espana!!
Message-ID: <3931@milton.acs.washington.edu>
Date: 5 Jun 90 05:39:28 GMT
References: <2669790120204258@vms.huji.ac.il>
Reply-To: amigo@milton.u.washington.edu (Michael Robertson)
Organization: University of Washington, Seattle
Lines: 27

In article <2669790120204258@vms.huji.ac.il> MARX@vms.huji.ac.il writes:
>Hi Netters,
>
>Recently I purchased the ATI 2400etc. Modem, In the brochure it says the
>MNP class 5 Data Compression abilities and also, the CCITT V.42 Error
>Control Protocol.
>can anyone explain what is the difference, what are the features
>and what's good and what's bad on those protocols?
	
	MNP is just a early protocol used to boost the modem's throughput
beyond what a non-MNP modem would do. MNP is just a built-in hardware protocol
much like any other software ones used in terms (Zmodem, Xmodem, etc.).
It also has some advantages in that it is designed specifically for modem transfers of course, and it does compression (if on). Anyhow, there is MNP classes
1 to 5, and supposedly 7 was developed, but never used much in modems until
	
	>V.42<.
	
	What V's are is the CCITT standards institute's way of defining how
a modem operates, and calling that a standard of sorts. They recognize only a
few that they can agree apon, such as V.32, or 2400 baud modems all work on
V.22. (V.32 is defined as a two-way full duplex 9600 baud transfer state). 
	
	But back to V.42/V.42bis, V.42 is just the CCITT's standard for
what was MNP-7. It gives you 3 times the modems throughput, so you can
expect to get into the 350-400 characters per second data transfer rates
if your connection is made to a V.42 modem.