[LEAPSECS] google abandons NTP ?

Steve Allen sla at ucolick.org
Mon Nov 26 13:45:34 EST 2012

On Mon 2012-11-26T18:30:09 +0000, Poul-Henning Kamp hath writ:

> Uhm, they run PTP, so what ?

That doesn't quite seem to be the case. The paper is at

In that is

The underlying time references used by TrueTime are GPS and atomic
clocks. TrueTime uses two forms of time reference because they
have different failure modes. GPS reference-source
vulnerabilities include antenna and receiver failures, local radio
interference, correlated failures (e.g., design faults such as
incorrect leapsecond handling and spoofing), and GPS system
outages. Atomic clocks can fail in ways uncorrelated to GPS and
each other, and over long periods of time can drift significantly
due to frequency error.

It seems to indicate that the "leap smear" is one of the features
implemented within this scheme.

Steve Allen <sla at ucolick.org> WGS-84 (GPS)
UCO/Lick Observatory--ISB Natural Sciences II, Room 165 Lat +36.99855
1156 High Street Voice: +1 831 459 3046 Lng -122.06015
Santa Cruz, CA 95064 http://www.ucolick.org/~sla/ Hgt +250 m

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