Hi Chris!
I have a week's worth of data now... Take a look at these graphics
http://www.flickr.com/photos/miguelbarbosagoncalves/8955346508/ and
http://www.flickr.com/photos/miguelbarbosagoncalves/8955346522/
One of them shows is the plot of the loopstats of my stratum 1 server. The
other one shows the offset determined every minute of their servers
compared to mine.
On 28 May 2013 16:11, Chris Albertson <[email protected]> wrote:
The "stratum 2" servers are by definition not connected to GPS. They get
their time from some other NTP server that is connected to an
authoritative
clock which may or may not be GPS. It looks like the "red server" has
I know that but I would expect good stratum 2 servers if they are keeping
their stratum 1 servers private and not available to the public.
rather smooth swings over around a "handful" of milliseconds. This is to
be excepted. It is within the normal range of what NTP does. Perhaps it
is a Windows PC running in some room where the temperature changes and the
network that connects it to the strum 1 server is loaded. I don't know
but
a handful of milliseconds is in the normal range. Yes it could be better.
I don't believe it is a Windows server but I could be wrong...
Also the curve is somewhat smooth. It does not look like noise from a
busy
network. It looks like their server really is moving around.
I believe they are on the same network. It looks like a temperature problem
really.
Thanks for all the input!
Kind regards,
Miguel
==========================================
Miguel,
I notice a step in the blue (ntp02) graph in:
http://www.flickr.com/photos/miguelbarbosagoncalves/8955346508/
and I think in the red (ntp04) graph as well. This suggests some change in
connectivity between your monitoring PC and both servers, so perhaps a
network change. Unless your stratum-1 server took a 2 millisecond step,
which seems unlikely.
Their ntp02looks well behaved, but their ntp04 is clearly not well behaved,
and disappointing for public service. In my own plotting program:
http://www.satsignal.eu/software/net.htm#NTPplotter
I find it useful to be able to plot the offset versus time of day, as
regular temperature variations tend to stand out - at least in my
environment where the heating switches on at the same time every morning.
For comparison on a similar time scale, you might like to look at my Windows
LAN-synced PCs here:
http://www.satsignal.eu/mrtg/performance_ntp.php?period=week#windows
so even if their servers were running Windows, they could be doing far
better than that your graph suggests. Could you plot offset versus time of
day?
Cheers,
David
--
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: [email protected]
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