Re: PSA: Clock drift and pkgin
"Maciej W. Rozycki" <[email protected]>
| Newsgroups | gmane.os.netbsd.ports.vax |
|---|---|
| Message-ID | <[email protected]> |
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