Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!iuvax!pur-ee!sage.cc.purdue.edu!aj0
From: aj0@sage.cc.purdue.edu (Eric Mulholland)
Newsgroups: comp.sys.apple
Subject: Re: Modems
Keywords: 2400 MNP
Message-ID: <3820@sage.cc.purdue.edu>
Date: 18 Mar 90 05:39:29 GMT
References: <9489@wpi.wpi.edu> <9522@wpi.wpi.edu>
Reply-To: aj0@sage.cc.purdue.edu (Eric Mulholland)
Followup-To: comp.sys.apple2
Organization: Purdue University
Lines: 33

)In article <9489@wpi.wpi.edu> jayg@wpi.wpi.edu (Jay Giurleo) writes:
)>Hi all.  I need some help in buying a new modem.  What I need to know
)>is whether MNP error protection circuitry is worth the extra money for
)>2400 baud modem.  Is it?  Thanks for the help!

In article <9522@wpi.wpi.edu> ear@wpi.wpi.edu (Eric A Rasmussen) writes:
)I would suggest that whether or not you need the extra protection depends on
)the quality of the phone line you are using.  Also, some cheaper modems are
)
)In theory, MNP can also result in slightly higher data transmission rates by
)utilizing data compression techniques, however this is only useful if you plan
)
)One problem with MNP modems is that you only gain the advantages of MNP if you
)are calling another modem with MNP, and I am almost positive that the modems

    As mentioned, MNP depends on the other modem supporting it to.  MNP is
only put in use when both modems connected support it.  I have noticed more
and more places starting to support MNP callers.  Around here, Compu$erve
and Tynet have both upgraded their modems from 1200 bps to 2400 bps MNP
level 4.  The level of MNP is inportant: with level 4, you get only a slight
inprovement in speed; with level 5, data is compressed and you get about
twice the speed (roughtly 4800 bps).  Of course any level of MNP protects
against line noise errors.
    If places you call support MNP and your phone lines aren't perfect, I'd
say the extra to get MNP is worth it.  If any place you call a lot supports
MNP level 5 or above, consider the extra speed improvement you will get.
Oh, if you do decide to go with MNP, make sure the modem supports at least
MNP level 5.  If it doesn't then think twice before getting it.
-- 
     ____
 Y_,_|[]|   Eric Mulholland
{|_|_|__|   aj0@sage.cc.purdue.edu
//oo--OO    ...!pur-ee!sage.cc!aj0