Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!zaphod.mps.ohio-state.edu!van-bc!cynic!curt
From: curt@cynic.wimsey.bc.ca (Curt Sampson)
Newsgroups: comp.dcom.modems
Subject: Re: Using High Speed Modems
Message-ID: <1991May24.095529.101@cynic.wimsey.bc.ca>
Date: 24 May 91 09:55:29 GMT
References: <156460@pyramid.pyramid.com>
Distribution: na
Organization: Mad Artists' Technological Hangout
Lines: 29

In article <156460@pyramid.pyramid.com>
  lstowell@pyrnova.pyramid.com (Lon Stowell) writes:

> In article <1991May23.040723.18039@cynic.wimsey.bc.ca> curt@cynic.wimsey.bc.ca (Curt Sampson) writes:
> >
> >Well, V.42 is an error correcting scheme.  It does introduce a certain
> >amount of "compression" when it strips the start and stop bits,
> >generally giving you about a 15% increase in bps rates no matter what
> >you transfer.
>   
>   Any V.22bis or V.32 modem does this....or any other phase
>   modulated modem.  Async data is NOT transferred end to end as
>   a bit stream.  It is converted to a sync format and xmitted.
> 
>   Any modem that needs to be configured for bits/character,
>   parity and/or async DTE baud rate is converting the data...and
>   recreating it at the far end.  

Wrongo.  NO V.22bis or V.32 modem, unless it includes V.42 or MNP
levels 3 and above, is stripping start and stop bits.  (And they do
not need to be configured for bits/character or parity unless they are
using V.42 or MNP levels 3 and above).  MNP3, MNP4 and V.42 all strip
start and stop bits.

cjs
-- 
Curt Sampson            | "[Atari's Race Drivin'] is more fun as a perverse
curt@cynic.uucp         | sort of flight simulator than a driving game."
curt@cynic.wimsey.bc.ca |           --Kevin Nomura (chow@netcom.com)