Re: PSA: Clock drift and pkgin

["Maciej W. Rozycki" <macro%orcam.me.uk@localhost>]

On Thu, 21 Dec 2023, Jan-Benedict Glaw wrote:

> > Unless I remember wrong, delay is merely how long it takes for packets to
> > travel back and forth to the ntp server. So it has no relation to jitter or
> > offset. It would rather be weird if delay suddenly started changing.
> 
> delay is ... "ping time".  jitter is a measure of how much ping times
> differ to each other.
> 
> It is kind of unreasonable that the jitter changes so much while delay
> seems to be always in the same region.

 Local sampling plays factor here: if the local time source is unreliable 
(i.e. the accuracy is low), then the jitter will be higher no matter the 
delay.  In older versions of `ntpq' jitter was called dispersion, which 
was maybe somewhat clearer: in statistics there is no correlation between 
the mean value (delay) and the dispersion (jitter).

  Maciej