[ntp:questions] how does jitter and delay measure time accuracy

C BlacK rblak at non.net
Wed Jun 29 22:51:33 UTC 2011


On 06/28/2011 06:42 PM, David Woolley wrote:
> chipper wrote:
>> Ok how do jitter and delay measure time accuracy?
> 
> You cannot measure time accuracy.  If you could, you would use the time that you were comparing against as the time to which to synchronise.
> 
> Jitter and delay measure the short term consistency in the time error measurements and the give an indication of the worst case error due to network asymmetry.  They are both measures of the quality of the time error estimate.
> 
> My feeling is that you are either not listening or you have unrealisable expectations.
where could I get a good explanation of the ntpd pll and the math behind it.

Thanks

Chip




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