[ntp:questions] National time standard differences
cjcrickmar at googlemail.com
Tue Feb 9 13:58:47 UTC 2010
On 9 Feb, 13:44, Joseph Gwinn <joegw... at comcast.net> wrote:
> In article <c2bcn.37983$Ym4.23... at text.news.virginmedia.com>,
> "David J Taylor"
> <david-tay... at blueyonder.delete-this-bit.and-this-part.co.uk.invalid>
> > > I've setup an NTP server in the south east asia region synchonising
> > > with regional NTP servers as well as a couple of servers I am
> > > responsible for in the US.
> > > remote st t when poll reach delay offset jitter
> > > ==============================================
> > > +Japan 1 u 454 1024 377 87.402 -0.560 0.056
> > > *Japan 1 u 476 1024 377 87.277 -0.810 1.542
> > > -NorthAmerica 2 u 427 1024 377 285.387 -17.741 5.084
> > > -NorthAmerica 2 u 429 1024 377 307.208 -17.061 0.083
> > > Is the above delta seen between Japanese and North American time
> > > sources purely the delta between the outbound / return network path or
> > > something else?
> > > Chris
> > Chris,
> > Most likely asymmetrical paths, yes.
> The wide area networks used for international connections are typically
> SONET rings, which are inherently asymmetrical.
> As one works around a ring, the poll response time is constant (being
> the perimeter of the ring), while the out and back times vary with
> position on the ring with respect to the server one is polling.
> Joe Gwinn
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