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From: craig@loki.bbn.com (Craig Partridge)
Newsgroups: mod.protocols.tcp-ip
Subject: Setting Initial Round-trip time
Message-ID: <8610292012.AA20495@ucbvax.berkeley.edu>
Date: Wed, 29-Oct-86 18:04:17 EST
Article-I.D.: ucbvax.8610292012.AA20495
Posted: Wed Oct 29 18:04:17 1986
Date-Received: Thu, 30-Oct-86 06:26:07 EST
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    I'm working on an implementation of RDP and am trying to find ways
to improve the round-trip time estimates.  The timeout algorithm is the
same as TCP's with the values suggested in RFC 889, but I've noticed that
choosing the wrong initial value for the estimated round trip time can
have a severe impact on throughput if the total number of packets is
relatively small and the link is lossy.

    I'd like to improve that performance by choosing better initial values.
This isn't something I know very much about so I'm soliciting advice.  How
do other people choose the initial value to put into the round trip estimate
equations?   What mechanisms do you recommend or strongly discourage or
disparage?

Craig Partridge
CSNET Technical Staff