[ntp:questions] Re: HowTo calibrate system clock frequency using NTP

Daniel Kabs daniel.kabs at gmx.de
Mon Feb 6 11:39:23 UTC 2006


Hello Terje!

Terje Mathisen wrote:
> ... I was just trying to persuade  the OP that it was unrealistic to expect
 > better than PPM agreement between various methods to determine the 
"average" drift value.

Of course I took your comments about the precision that one can 
reasonably expect from these experimant seriously. I didn't mean to 
argue against them. I just wondered whether the two experiments showed a 
difference of 500 ms per day because I was actually measuring different 
values (live vs. averaged drift value).


 > [two modem calls ... free-run for a week]
> The resulting offset was 60 ms. :-)

You achieved an exceptionally good precision of 60ms per week with just 
two phone calls. I have all the "intellegence" of NTP and only achieve 
500 ms per day. I should try harder, don't you think? :-)


Cheers
Daniel




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