Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!wasatch!helios.ee.lbl.gov!ace.ee.lbl.gov!leres
From: leres@ace.ee.lbl.gov (Craig Leres)
Newsgroups: news.software.nntp
Subject: Re: Minutes ... (nntpxmit)
Message-ID: <2955@helios.ee.lbl.gov>
Date: 7 Jul 89 02:03:28 GMT
References: <32853@apple.Apple.COM>
Sender: usenet@helios.ee.lbl.gov
Reply-To: leres@helios.ee.lbl.gov (Craig Leres)
Organization: Lawrence Berkeley Laboratory, Berkeley
Lines: 31

Erik E. Fair writes:
> quickly. If everyone is running with what we recommended in the
> original NNTP release (every 10 minutes), then it takes an hour to go
> six hops. I'd like to see it take six minutes (i.e. run nntpsend every

If I run nntpsend every 10 minutes, I would expect it to take 5 minutes
(on average) for me to propagate a new article. I would also expect it
to take 30 minutes (on average) to travel six hops.

I suppose my posting has the potential for starting a minor probability
and statistics war (like the one on engine counting in comp.risks) so
perhaps I should state my assumptions in an attempt to cut out the
simpletons.

My first assumption is that not everyone clocks are synchronized. A
small sampling of internet hosts at several sites shows a spread of
about plus or minus 3 minutes.

My other assumption is that not everyone who runs nntpsend with a 10
minute interval starts on the hour. Even if you (stupidly) assume that
every single nntp peer's clock is synchronized, I don't see how you can
assume that they all start their cycles on the hour (my own system
starts at 3 minutes past the hour or 7 minutes before the hour,
depending on how you look at it).

Note that even if every host starts their cycle on the hour, the
un-synchronized clock syndrome will make it take almost 10 minutes for
an article to travel in one direction and almost 0 minutes for it to
travel in the other direction. This averages out to 5 minutes.

		Craig