[ntp:questions] Re: isolated network + accuracy

Bjorn Gabrielsson bg at lysator.liu.se
Tue Dec 14 08:33:53 UTC 2004

"Richard B. Gilbert" <rgilbert88 at comcast.net> writes:

> Bjorn Gabrielsson wrote:
> >"Richard B. Gilbert" <rgilbert88 at comcast.net> writes:
> >
> >
> >>Using an internet server as a time source will almost certainly not
> >>allow you to achieve 1ms accuracy!  10ms accuracy is possible over the
> >>internet but cannot be guaranteed.
> >>
> >
> > I get sub 1ms time from internet servers.
> The internet servers I use tend to wander within plus/minus 5-10ms of
> my GPS receiver!!  I'm using the best servers I can find and I've seen
> far worse than the ones I finnally settled on.   

You have 5-10ms offsets. I usually have 0.1-0.5ms. 

> Your milage may vary.


> > My Linux computers shows no problem reaching below 1ms.
> My RedHat Enterprise Linux 3.0  workstation rarely runs an offset less
> than 5ms.  Once again your milage may vary!!

My FC2 x86_64 workstation very rarely sees an offset above 0.5ms. Its
getting its time from just my ntp server. Not performing better using
a server 0.3ms away compared to using public intenet servers 10-20ms
away is kind of curious...

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