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From: naftoli@aecom.UUCP
Newsgroups: comp.dcom.modems
Subject: Re: 2400 Baud MNP Correction Synchronization
Message-ID: <912@aecom.UUCP>
Date: Fri, 20-Feb-87 10:26:36 EST
Article-I.D.: aecom.912
Posted: Fri Feb 20 10:26:36 1987
Date-Received: Sat, 21-Feb-87 16:47:28 EST
References: <2607@well.UUCP>
Organization: Albert Einstein College of Medicine, NY
Lines: 34

In article <2607@well.UUCP>, ewhac@well.UUCP (Leo 'Bols Ewhac' Schwab) writes:
> 
> 	I have a MultiTech 224E error correcting modem.  It's got automatic
> fallback, both flavors of Hayes compatability, etc.  It also has MNP error
> correction in hardware.
> 
> 	I've been having trouble with this.  When I call up some local
> non-MNP modems in Auto-Reliable mode (as the manual calls it), I get
> garbage, as though the modem I'm calling is running at the wrong baud rate.
> Sometimes (rarely), this doesn't happen, and I get a good connection (with a
> non-MNP modem (by the way, I've never connected with an MNP modem)).
> 
> 	Am I doing something wrong, or is the act of MNP handshaking causing
> the destination modem to see a framing error, which many systems interpret
> as a signal to change baud rates?

Yes, the auto-reliable handshake isn't always transparent and will send 
garbage to non-MNP modems.  The same thing happens with Microcom AX2400s so 
it's not just the Multitech that's doing it wrong (I have one of those too).  

What I do is simply not use it.  I just set the modem to either MNP or non-MNP 
depending on who I'm calling (in fact my terminal program does this for me).  
I am also not crazy about it because it takes longer to connect to non-MNP 
sites since it first has to decide whether the other is MNP or not; this takes 
a few seconds.  

However, we do have our dialin Microcoms set to auto-reliable.  This way
both MNP and non-MNP work fine when they dialin (and no glitch seems
to be transmitted to the host).
-- 
Robert N. Berlinger
Systems Analyst, Scientific Computing Center		Compuserve: 73047,741
Albert Einstein College of Medicine			Easylink:   62956067
UUCP: ...{philabs,cucard,pegasus,rocky2}!aecom!naftoli	GEnie:	    R.Berlinger