"Spoon" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > Maarten Wiltink wrote:
>> [...] could you monitor the buffer length and adjust frequency >> on system B from that? If it's slowly draining, slow down B a little; >> if it's growing, speed it up ever so slightly. Just like NTP does, >> really. > > The very hard part (for me) is seeing that B's buffer is in fact slowly > draining when there is a lot of jitter on the link between A and B. > > I've tried using an exponentially-weighted moving average to filter the > jitter out, but it didn't work as well as I had hoped. That is when I > turned to NTP. I'm trying not to reinvent the wheel. > > Are you saying I should use the theory in NTP but not the daemon? Well, not _all_ the theory. Just the basic idea of slowing down a fast clock and speeding up a slow one. If it became too much work, I'd say you're better off just adopting NTP, all of it. But the jitter problem is (in retrospect) obviously inevitable - if you didn't have a jitter problem, you wouldn't have _any_ problem. So you need to filter, and that's the first step towards a full, but very roundabout, NTP implementation. Incidentally, IIAMN (and I've been before) NTP uses a median filter to remove jitter. That throws away more information than a weighted average, which in this case is a good thing. You might try that before calling it a day. Groetjes, Maarten Wiltink _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
