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From: kre@munnari.OZ (Robert Elz)
Newsgroups: net.mail
Subject: Real Networks (was Re: Neighbor optimized away)
Message-ID: <1104@munnari.OZ>
Date: Fri, 9-May-86 14:24:56 EDT
Article-I.D.: munnari.1104
Posted: Fri May  9 14:24:56 1986
Date-Received: Sun, 11-May-86 05:11:30 EDT
References: <4509@dartvax.UUCP> <2124@peora.UUCP>, <912@decuac.DEC.COM> <6657@utzoo.UUCP>
Organization: Comp Sci, Melbourne Uni, Australia
Lines: 21
Keywords: uucp pathalias

In article <6657@utzoo.UUCP>, henry@utzoo.UUCP (Henry Spencer) writes:
> Clearly, then, a Real Network has to have connections live all the time so
> that it knows when machines go down.

This isn't necessary or sufficient.  The only way that (I am aware
of) to determine when a machine goes down is for it to tell you
that it is going down.  For this, decicated connections will do,
as will dial up connections.

It the host goes down without telling you in advance, then all you
can ever determine is that you can't communicate with it when you
want to, you might surmise that its down, but there's no way you
can know.  Now, with either dedicated or dial up links, you can
make this assumption whenever its appropriate - on a dedicated
link it might be appropriate after a few seconds or minutes.  On
a dial up link, it might be appropriate after a few hours or days.

In either case, a Real Network can then reroute traffic after it
has made this determination.

Robert Elz	kre%munnari.oz@seismo.css.gov	seismo!munnari!kre