> From: Attila Kinali <[email protected]> > Can you tell a little bit how your device looks like on the inside?
GPS is a Ublox. MCU is Cortex-M7 and does not run any OS - just main loop with prioritised interrupts. Network stack is hand-made. I don't use saw-tooth correction in this device because +-11ns is not worth correcting for NTP application for such a budget device. If you can build a test NTP client system that can detect sawtooth 10ns offset from the NTP server I'd like to know how you did it. >> When you come to testing I can highly recommend placing your prototypes in >> public NTP pool and asking the admins to add it to .ch zone - you are >> guaranteed to get full 110kpps traffic spikes that will help to flush out >> bugs. > > Why specifically the .ch zone? IIRC you are located in the uk. > I am running an NTP server in the .ch pool and have not yet noticed any large > spikes. (ok, my monitoring is rather crude and if the spike is very short > lived, i wouldnt notice it) Sorry, it was a typo - I meant Chinese zone (.cn) Spikes usually happen around full or half-hour and last only few seconds but you often (about once a day) get true 100% fully saturated wire speed with packets coming in (and out) back to back. The theory behind these spikes is interesting - most probably they are results of SNTP clients running from cron jobs. So, ironically, the more accurate time they receive from you, the more concentrated their behaviour becomes. Leo _______________________________________________ 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.
