Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!A.ISI.EDU!CERF
From: CERF@A.ISI.EDU
Newsgroups: comp.protocols.tcp-ip
Subject: Re: TCP/IP close connection TIME_WAIT ?
Message-ID: <[A.ISI.EDU].1-Sep-89.03:54:22.CERF>
Date: 1 Sep 89 07:54:00 GMT
References: <17529@bellcore.bellcore.com>
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Phil and Sandy have done a good job of explaining the mechanism
and rationale for TIME_WAIT. During the design phase of TCP,
tremendous effort was put into exploring, through case
analysis, various sequences of events in various orders. 

The "two armies" problem is also called the Byzantine
Generals problem in the literature on synchronization.
There are some wonderfully complicated variations in
which there are more than two generals and some of them lie.

In any case, no amount of waiting and acking will guarantee
anything - but the states are there to reduce the possibility
that a successful session is considered a failure for lack
of an ACK. Generally, though, such designs fail safe in that
a truly unsuccessful session is not accidently considered
successful though a successful one may be mislabelled a
failure.

Vint