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

chipper black at intre.nt
Sun Jun 26 19:52:40 UTC 2011


If the ntp client needed to be withing .5 milliseconds of the server,how could I tell if the jitter and delay were to
much to support this kind of accuracy?

Thanks

Chip


Richard B. Gilbert wrote:
> 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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