Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!easy!lron
From: easy!lron@uunet.uu.net (Dwight Hubbard)
Newsgroups: comp.sys.amiga.misc
Subject: Re: v.32, v.32bis, v.42, v.42 bis
Message-ID: <1899d952.ARN0bf6@easy.hiam>
Date: 29 Jan 91 23:50:26 GMT
References: <GHOST.91Jan13020101@bucsf.bu.edu> <sJkiw2w162w@zooid>
Reply-To: easy!lron@uunet.uu.net
Followup-To: comp.sys.amiga
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In article <sJkiw2w162w@zooid>, Lima Bone writes:

> ghost@bucsf.bu.edu (Jay Adelson) writes:
> > Can someone please tell me what the difference between the standards
> > v.32, v.32bis, v.42, v.42bis is? And which modems have which? (Between
> > the Telebit and the USRobotics?)

> Wayll, I think any modem with v.42bis has also v.32bis..I have a USRobotics
                                ^^^^^^^^^^^^^^^^^^^^^^^^^
                    No, they are two different types of standards
> HST with v.42bis and it also has the capability of v.42bis...which I think
> is merely the name of the data-compression that it uses. I could be wrong,
> but that's what it looks like.

V.32    is a modulation standard to get 9600 full duplex, it is supported by
        the Telebit T2500 and the USR Dual Standard.  Both companies make V.32
        only modems as well.  V.32 modems from Intel and PP&S tend to be
        cheaper than either the Telebit or the USR V.32 modems.

V.32bis is a modulation standard to get 14.4K full duplex, it is supported
        by the newer USR Dual standard modems as well as modems made by
        DigiComm.  Final approval of V.32bis is not until next month, however
        it is not likely to change.

V.42    is a standard for error detection/correction MNP levels 1-4 are a
        subset of V.42, allowing V.42 modems to use MNP error detection/
        correction.  This mode is supported by the Telebit T2500, the USR
        Dual Standard and the USR HST 14.4.  It is supported by most newer
        V.32 modems by other companies as well.

V.42bis is a standard for on the fly compression.  It normally comes with
        V.42 error correction/detection.  V.42bis allows a maximum compresion
        of 4:1 however like any other compression system it will not cause
        a very large increase in speed on compressed files, unlike MNP-5 it
        will not however increase the amount of data (slowing things down).
        This is supported by the Telebit T2500 and the USR Dual Standard and
        HST 14.4 modems.  It is supported by most of the newer V.32 modems as
        well.

-Dwight Hubbard                     USENET  : uunet!easy!lron
-Kaneohe, Hawaii                    CFR     : 31:910/101 (Dwight Hubbard)