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From: CERF@USC-ISI.ARPA
Newsgroups: mod.protocols.tcp-ip
Subject: Re:  Zero window probes
Message-ID: <[USC-ISI.ARPA]12-Nov-85.06:52:07.CERF>
Date: Tue, 12-Nov-85 06:52:00 EST
Article-I.D.: <[USC-ISI.ARPA]12-Nov-85.06:52:07.CERF>
Posted: Tue Nov 12 06:52:00 1985
Date-Received: Wed, 13-Nov-85 07:59:22 EST
References: <851108205728.000456@CISL-SERVICE-MULTICS.ARPA>
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Approved: tcp-ip@ucbvax.berkeley.edu

John,

The philosophical basis for the TCP design, if not stated explicitly,
was that the TCP protocol and implmentation could not and should not
make too many timeout decisions on behalf of a using process. Only
the using process (or perhaps a person) knows how long it is willing
to "wait" for some action.  Consequently we assigned no value for
timing out the condition you describe and instead assumed that the
using process would eventually close the connection unilaterally
when it wanted to.  of course, if you get no ACK back from the probe,
you timeout and report this to the using process but you still do not
unilaterally close the connection at the TCP level.  

Vint