Re: PSA: Clock drift and pkgin

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

On Thu, 21 Dec 2023, Maciej W. Rozycki 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).

 Self-correction here: the mean value here is of course the offset shown 
by `ntpq' and not the delay (and jitter is the offset's dispersion).  
Sorry for the confusion.

  Maciej