Recent NTP pool traffic increase

Majdi S. Abbas msa at latt.net
Fri Dec 30 21:04:15 UTC 2016


On Fri, Dec 30, 2016 at 02:08:50PM -0500, Allan Liska wrote:
> In the United States that would the United States Naval Observatory
> (USNO) Master Clock (http://tycho.usno.navy.mil/).  You can read more
> about it here:
> http://motherboard.vice.com/read/demetrios-matsakis-and-the-master-clock

	One of the things I have learned as a time hobbyist is that if
something involves time, and you think there is a simple answer, you
are probably wrong.  :)

	USNO is our military time keeper -- NIST keeps time for civil
purposes, and while they coordinate to stay in reasonably close
proximity, even they don't agree.  Even better, the GPS clocks are
run by (and corrections distributed) by the Air Force, not the Navy.
And they have made mistakes in recent memory.

	From an international perspective, BIPM is responsible for UTC,
but it is only figured well after the fact.  We distribute "UTC" via
NTP, but it's not true UTC since that is not figured in real time,
it's much, much coarser, and everyone's local views differ anyway.

	For an idea just how many components there are, take a look
at BIPM's Circular T:

ftp://ftp2.bipm.org/pub/tai//Circular-T/cirthtm/cirt.347.html

	But back to the point...while UTC is an international
time scale, individual national labs and institutions keep their
own views of it, and correct periodically...then they distribute
these timescales, and in some fashion we attempt to get a coarse
version of it onto the Internet in real time.

	There is no one authority responsible for this, and you
may take time from any one (or more) of them that you choose.
And for this reason, there is no single authority for time 
distribution on the Internet -- because there is none for the
world as a whole, either.

	We /can/ have an authoritative system for something 
like host naming, where it's comparatively easy to produce a
single authoritative source.  Timing is not nearly such a
simple subject.

	Cheers,

	--msa


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