[ntp:questions] how does jitter and round trip time affect the accuracy of the local clock?

Richard B. Gilbert rgilbert88 at comcast.net
Sun Jun 26 19:04:17 UTC 2011


On 6/26/2011 11:36 AM, chipper wrote:
> How doe Jitter and round trip time affect local time clock time acccuracy?

They don't *affect* the accuracy, they measure it!
>
> When looking at the jitter, what values would tell me that the phase
> noise would make the local clock in accurate?
>
> Are there any "Rules of thumb" to go by when looking at jitter and delay
> to determine local clock accuracy
>
> Kindly
>
> Chip
>
>

How close do you need the time to be?  Many people live most of their 
lives with clocks that may well be off by a minute or two.

Other people need numerous clocks to agree with each other +/- a few 
seconds, milliseconds, or microseconds and don't care that the time is 
not correct as long as all the clocks involved agree within the 
specified tolerance.

Still others need to know the time +/- a few microseconds or +/- a few 
nanoseconds.

Specify your needs.  If you can't figure out how to meet your needs,
post a description of your requirements and somebody might be able to 
give you a clue or two or three.




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