[time-nuts] Divide by five ->Ensemble

Poul-Henning Kamp phk at phk.freebsd.dk
Mon Nov 10 01:59:17 EST 2014

In message <4CDC0090-DD4B-4380-ACC1-40A80D3BC20C at n1k.org>, Bob Camp writes:
>Here’s what I’m saying:
>The NTP algorithm as it is written and as it is implemented results
>in an output clock that does *not* improve when a number of very
>good clocks are being used [...]

The crucial word here is "good clocks".

A "good clock" in NTP is nearby and because it is nearby, the chances
of several of them overlapping is usually not high enough for any
clock combining to happen.

The NTP algorithms were built for 10-100msec packet delays, not
low microsecond packet delays.

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.

More information about the time-nuts mailing list