-------- In message <[email protected]>, Magnus Danielson writes:
>The NTP scatter-plot wedge is another way to present it, and finding the >"tip" of that wedge is really about finding the min-value of delay in >each direction prior to doing the two-way time-transfer equations. The important part about the wedge diagram is that the wedge is not filled out. With a very large probability only one of the two packets is impacted by extra delays. The current NTP filter totally fails to exploit this fact and performs quite a bit worse because of it: A median filter is really not a suitable way to handle that situation. But steering back to the original topic again: You really should not look at NTP for clock-ensemble or clock-steering examples, the challenges NTP copes with, are nothing like the challenges you have with a bunch of local high-quality frequencies. There used to be an academic paper on timing.com's home-page about their clock-ensemble algorithm called something like "Advances in Time-Scale Algorithms". It's not super detailed but it was certainly a much better place to start than NTP source or documentation -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [email protected] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
