On Sat, Nov 10, 2012 at 13:18 UTC, David J Taylor wrote: > For those who may not have seen it elsewhere, I've been playing with a > Raspberry Pi computer and a couple of different GPS/PPS receivers (Trimble > and u-blox). A stratum-1 NTP server with a 4W power consumption: > > http://www.satsignal.eu/ntp/Raspberry-Pi-NTP.html > > It's all a bit experimental, but if the note is of use to anyone - great! > Not tested for load capacity - does anyone have a Windows program for > stress-testing an NTP server.
I am not aware of any, but you might be able to provide one with just a bit of work using the socket API, assuming that's exposed to Delphi. However, if you have a reasonably stable public IPv4 address and can port-forward UDP 123, you my find you can use the pool to generate load, modulated by the bandwidth knob controlling the frequency of your IP being in pool.ntp.org DNS responses. For that approach to be feasible you need to have packet counters outside the R. Pi, such as in your NAT router or a managed switch, that you could compare with its counts to detect the failure to respond. In the US, a pool server set at the maximum bandwidth (1 Gbps) just now saw 1400 packets per second over a one-minute sample. Presumably a UK pool server at the same setting would get a fraction of that traffic. I think the long-term average is lower, too, as I sampled near the top of the hour where pool servers get slammed the worst by cron and remember a few months ago the server typically getting closer to 200 requests/sec over longer samples. I suspect your ADSL will be able to deliver more packets/sec than the Pi can handle, but you should be mindful the link may be the limiting factor. Cheers, Dave Hart _______________________________________________ pool mailing list [email protected] http://lists.ntp.org/listinfo/pool
