[ntp:questions] different request pattern

arne_woerner at yahoo.com arne_woerner at yahoo.com
Tue Jul 1 07:41:35 UTC 2008

On Jul 1, 7:10 am, David Woolley
<da... at ex.djwhome.demon.co.uk.invalid> wrote:
> arne_woer... at yahoo.com wrote:
> > 2. "offset per second" describes the estimated offset-difference after
> > a second...
> > i compute it like this (dont laugh :-) ):
> > (adjtime_offsets + estimated_offset_to_server_X)/T
> > let T be the time when the offset to server X was 0
> > let adjtime_offsets be the sum of the adjtime() offsets in the last T
> > seconds...
> That seems to me to be an estimate of the local machine's clock
> frequency, evaluated over an excessively short period in relation to
> network timing jitter.  10ms/s would be 10,000 parts per million, which
> is much much higher than you would get even from a real false ticker,
> and could only really represent the result of jitter.  On a heavily
> loaded connection, traffic variations can results in offsets varying by
> hundreds of milliseconds (relative to true time).
yup... the round trip time should be assessed too... historically...

who said something about 10ms/s? if i did it, i was wrong...

i was talking about this: http://www.pool.ntp.org/scores/
unluckily its refids and its server's ntpq-information r not recorded,
so that we just have my "testimony"... :)


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