[time-nuts] An embedded NTP server
David J Taylor
david-taylor at blueyonder.co.uk
Wed Dec 26 11:18:08 UTC 2012
From: Michael Tharp
> Oh, and your Windows box 172.24.0.68 is either poorly configured or
> broken - they can work much, much better than yours illustrates as I
> expect you know.
Yes, it's not healthy. I installed Meinberg's NTP build and configured
it using defaults other than the server list but it seems to not be
tracking well. Right now it's "only" 30ms off but as shown in the forum
snippet it makes excursions into the hundreds. Still an improvement over
default Windows timekeeping but I'd love for it to work properly.
-- m. tharp
Michael, for comparison, I've put up a couple of plots of Windows using
Internet-only servers running on Windows-7 and Windows-8 PCs. The Windows-8
PC should be better as it has a more precise GetSystemTime API (it's called
GetSystemTimePreciseAsFileTime). This is using the newish POOL directive
which provides about 10 NTP servers.
Roll the mouse over the different captions below the graphs to see the
various statistics. The Windows-7 PC shows offsets in the range 10 - 20 ms,
with averaged jitter in the 3 - 9 ms range. Were my Internet connection
more heavily loaded these figures could be worse. Windows-8 has offsets in
the -3 to +5.5 ms range, with averaged jitter eventually 0.4 to 0.6 ms. I
guess if your Internet connection is not as good as mine you might be seeing
such large offsets.
These are running a recent NTP development version which you could download
and I would recommend this as it has significant improvements over the
Meinberg in the Windows port.
SatSignal Software - Quality software written to your requirements
Email: david-taylor at blueyonder.co.uk
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