[ntp:questions] Tighter regulation?

Mischanko, Edward T Edward.Mischanko at arcelormittal.com
Sun May 26 04:23:26 UTC 2013


> -----Original Message-----
> From: questions-bounces+edward.mischanko=arcelormittal.com at lists.ntp.org
> [mailto:questions-
> bounces+edward.mischanko=arcelormittal.com at lists.ntp.org] On Behalf Of
> unruh
> Sent: Saturday, May 25, 2013 9:27 AM
> To: questions at lists.ntp.org
> Subject: Re: [ntp:questions] Tighter regulation?
> 
> On 2013-05-25, Mischanko, Edward T <Edward.Mischanko at arcelormittal.com>
> wrote:
> >
> >> -----Original Message-----
> >> From: Charles Swiger [mailto:cswiger at mac.com]
> >> Sent: Friday, May 24, 2013 1:01 AM
> >> To: Mischanko, Edward T
> >> Cc: questions at lists.ntp.org
> >> Subject: Re: [ntp:questions] Tighter regulation?
> >>
> >> On May 23, 2013, at 10:02 PM, "Mischanko, Edward T"
> >> <Edward.Mischanko at arcelormittal.com> wrote:
> >> > It takes too long to figure out it needs a more aggressive
> correction.
> >> > If I leave maxpoll at the default of 1024 seconds, my clock drifts
> >> outside
> >> > of 5 milliseconds consistently.
> >>
> > [Mischanko, Edward T]
> >
> > Measured by the best time sources I have available.  I am saying that my
> 
[Mischanko, Edward T] 

What details do you want?  I am syncing to 10 stratum 4 servers in my case.
  Servers outside of my LAN are blocked by the corporate firewall.

> And maybe it is that "best" that is wrong. Why not give the details so
> we can decide?
> 
> >  clock will drift to 5 milliseconds at maxpoll 10 and polling does not
> >  decrease to a level that will bring my clock back to an offset of +/- 1
> >  millisecond.
> 
> Note that on maxpoll 10, the clock will freerun for about 7000 sec
> between disciplines. 5ms in 7000 sec is about 1PPM.

[Mischanko, Edward T] 

I don't believe the room temperature changes much at this computer's
 location.

Now if your computer
> heats up and cools down by 20C over an hour that could change the clock
> by a few ms. And ntpd is slow to respond to changes in clock rate.
[Mischanko, Edward T] 

If I do maxpoll 8, then I get regulation within 1 millisecond.  What other
 details would you like?  I can post my loopstats in the future if that
 would be helpful?

> What happens if you do maxpoll 6? Give us details, not vague statements.
> 
[Mischanko, Edward T] 

I do not know how to analyze the peerstats file, but I can post it if that
 would help?

> Also try plotting peerstats and the offset as a function of time.
> 


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