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From: mouse@mcgill-vision.UUCP
Newsgroups: comp.dcom.lans
Subject: Re: Ethernet Null Modem- Ever Heard of It?
Message-ID: <711@mcgill-vision.UUCP>
Date: Fri, 27-Mar-87 21:07:19 EST
Article-I.D.: mcgill-v.711
Posted: Fri Mar 27 21:07:19 1987
Date-Received: Sat, 4-Apr-87 20:08:20 EST
References: <383@oblio.UUCP>
Distribution: na
Organization: McGill University, Montreal
Lines: 29
Keywords: Ethernet TCP-IP connection direct transceiver

In article <383@oblio.UUCP>, charlie@oblio.UUCP (Charlie Richardson) writes:
> Is there such a thing as an Ethernet null modem cable which allows
> you to connect any TWO machines directly, i.e. from the xceiver port
> on one system to the port on the other WITHOUT using a transceiver?

> It seems to me that it might be possible with TCP/IP only; you could
> [theory]

What could the protocol you're using possibly have to do with it?  I
can't see that it could matter whether you're using IP, XNS, ND,
Chaosnet, or whatever.  What am I missing?

> The only joker in the deck would be how to handle collision detect;

If there's any contention when they both try to transmit at once then
you handle it same as on a regular Ethernet.  If there's no contention
then data can flow both directions and you just wire the collision
detect down to a constant logic signal, whichever way means "no
collision".

Am I just exposing my ignorance of Ethernet or is this really no
problem?

					der Mouse

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