Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.3 alpha 4/15/85; site ucbvax.ARPA
Path: utzoo!watmath!clyde!burl!ulysses!ucbvax!tcp-ip
From: tcp-ip@ucbvax.ARPA
Newsgroups: fa.tcp-ip
Subject: Re: Speaking of 4.2 time programs
Message-ID: <7812@ucbvax.ARPA>
Date: Wed, 5-Jun-85 02:49:56 EDT
Article-I.D.: ucbvax.7812
Posted: Wed Jun  5 02:49:56 1985
Date-Received: Thu, 6-Jun-85 08:04:21 EDT
Sender: daemon@ucbvax.ARPA
Organization: University of California at Berkeley
Lines: 22

From: MILLS@USC-ISID.ARPA

In response to the message sent  03 Jun 85 23:35:09 EST (Mon) from cak@Purdue.ARPA

Chris,

Mike O'Connor (oconnor@dcn9) installed a program on our Sun workstation
which mumbles the DCNet protocols via our local Ethernet. Unfortunately,
the Sun clock wanders all over the place and is unsuitable for locking
to anything better than a windmill generator. I don't think you want
the DCNet protocols, anyway, but some sort of similar protocol that
operates over real Internet paths. That's not trivial, as a grok at
RFC-889 should show. The fuzzies have a highly evolved tracking algorithm
involving both linear and nonlinear filtering and estimation in order
to achieve the claimed accuracies even on local nets. It would be a useful
and positively fascinating exercise to adapt these algorithms to real
Internet dynamics using UDP for coarse tracking and ICMP timestamps for
fine synchronization. Someone out there should cop a Master's thesis for
going after this one with hammer and tongs.

Dave
-------