[ntp:questions] stepping and slewing

Martin Burnicki martin.burnicki at meinberg.de
Fri May 11 07:25:19 UTC 2007


Dave,

David L. Mills wrote:

> Serge,
> 
> The NTP clock discipline doesn;t work like that. The ntpdate and
> imitator compute an offset correction, hand off the adjtime() and go
> home. The NTP clock discipine algorithm incorporates a feedback loop
> which includes a proportional control with time constant of several
> teens of minutes. See the arthictecture briefing at the NTP project page.

I have seen lots of astonished requests why it takes so long for ntpd to
adjust a small initial time offset of e.g. e couple of milliseconds.

Wouldn't it be possible and useful to start up with a smaller time constant
which allowed for faster initial corrections, and then increase the time
constant to the final value to move over to the normal behaviour of ntpd?

Martin
-- 
Martin Burnicki

Meinberg Funkuhren
Bad Pyrmont
Germany




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