On Jan 23, 2009, at 11:19 AM, [email protected] wrote: > As shown by the log at pool.ntp.org > (http://www.pool.ntp.org/scores/72.64.118.118/log?limit=50 > ), your time server sometimes gives > out time responses off by around 100-200ms. The log file is just > showing > that NTP is recognizing those inaccuracies (or, possibly, > recognizing things that aren't inaccuraciess, so incorrecting the > time) and stepping the clock to fix it
That is what I was afraid of. > This could be caused by many things, but it's likely just BitTorrent > uploads causing congestion causing high ASYMETRIC network latency > and jitter. Throttle the upload to something well under your maximum > upload and see if the problem goes away. I will give that a try. > Low-bandwidth, poor-quality connections like ADSL are poorly suited > to services such as NTP, especially if they're pushing a significant > amount of traffic. I'm on FiOS. > Shaping may help (basically, you want to avoid many packets getting > queued (so you throttle on your router below the speed of the > modem), and prioritize time over almost all other traffic, so that > *hopefully* those packets won't get delayed significantly) I haven't played with shaping with my router (m0n0wall on a soekris 4801), but the tools are there. This should be relatively easy to do since the NTP server is on my DMZ and bitorrent thingie is running on the LAN. Also, I'm not wedded to the idea of participating in Bittorrent. I had just grabbed knoppix and FreeBSD-7.1 via torrent, and thought that I should continue to serve them up. So if tuning Transmission and shaping on the router don't work, I'll just stop with it all together. Cheers, -j _______________________________________________ timekeepers mailing list [email protected] https://fortytwo.ch/mailman/cgi-bin/listinfo/timekeepers
