In article <[EMAIL PROTECTED]>, Rick Jones <[EMAIL PROTECTED]> wrote:
> taps with clue bats, is if I can take the difference in offset between > each client and the time server and ass-u-me that is the difference in > time between the two clients. Or do I have to do something ntp-like No. If NTP is working properly, it is actually an indication of the order of magnitude of the error you can expect in measuring the combination of network and system timing. The actual system timing variation should be considerably less than this, but there may be a systematic bias, even if offset is consistently almost zero. The NTP clock discipline will strive to zero the offset, but cannot correct for round trip asymmetry. Any individual offset measurement will contain a measurement error. That measurement error will be of the same magnitude as the measurement error you will get with your application. If you are interested in one way latency, you are interested in asymmetry! To the extent that the above is not true, either you are making use of information not available to NTP (like recent temperature excursions), or the NTP algorithms need fixing. You need to use local, probably GPS, reference clocks, with pulse per second feeds, to remove network asymmetry. _______________________________________________ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions