From: Hal Murray <hmurray@megapathdsl.net>
To: bloat-devel@lists.bufferbloat.net
Subject: Re: One-way delay measurement for netperf-wrapper
Date: Sun, 01 Dec 2013 21:45:26 -0800 [thread overview]
Message-ID: <20131202054526.523C0406060@ip-64-139-1-69.sjc.megapath.net> (raw)
toke@toke.dk said:
> - Is clock drift something to worry about over the timescales of these
> tests?
It depends. :)
How long are you running the tests? How accurate do you expect the timings
to be?
ntpd assumes the network delays are symmetric. It's easy to break that
assumption by sending a lot of traffic in one direction. ntpd tries to avoid
that problem. It remembers the last 8 packets to a server and uses the one
with the shortest round trip time. If you run tests for long enough you will
overflow that buffer. The time scale is somewhere between minutes and hours.
--
These are my opinions. I hate spam.
next reply other threads:[~2013-12-02 5:45 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-02 5:45 Hal Murray [this message]
2013-12-02 8:34 ` Toke Høiland-Jørgensen
-- strict thread matches above, loose matches on Subject: below --
2013-11-28 20:30 Hal Murray
2013-11-28 18:51 Toke Høiland-Jørgensen
2013-11-29 8:45 ` Eggert, Lars
2013-11-29 9:42 ` Toke Høiland-Jørgensen
2013-11-29 10:20 ` Eggert, Lars
2013-11-29 13:04 ` Toke Høiland-Jørgensen
2013-11-29 14:30 ` Eggert, Lars
2013-11-29 16:55 ` Dave Taht
2013-12-02 18:11 ` Rick Jones
2013-12-02 18:20 ` Toke Høiland-Jørgensen
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