Richard B. Gilbert wrote: > It may also be worth noting that Windows does not use NTP software; > Microsoft supplies a broken implementation of SNTP called W32TIME. NTP > software is available for Windows if you wish to download and install it
Windows 2003 Standard Server with Service Pack 1 seems to have a much better "almost real" NTP service. It's not just SNTP anymore. I've been testing it compared with NTPv4 for a few weeks now, but I haven't had a chance to do a full write up yet. Here's a quick outline of the results, when Win2003sp1 or R2 is compared with NTPv4 running against the same set of Stratum-1s from the same network: - it keeps reasonable average offsets with NTPv4 at stratum 2 for at least a week (my test length) - it selects its reference clocks roughly the same as NTPv4, usually hopping to a new reference server a few minutes ahead or behind NTPv4 as network conditions warrant - it polls servers at similar intervals to NTPv4 - it advertises stratum and reference ID correctly (tested with stratum 1 & 2 servers) The big caveat: Windows 2003 SP1 time service only advertises -6 precision in its packets, and unfortunately, this claimed precision seems about right. On the graphs I've made so far, it looks like it steps the clock in ~10 ms increments rather infrequently. The result is a far higher jitter than you would see with NTPv4, although the offsets are almost always within 20 ms of UTC, and a moving average is within a couple of ms of NTPv4's offset moving average. Basically, I'd say that w32time in Windows 2003 SP1 and R2 is definitely more RFC-compliant than the SNTP service in previous Microsoft offerings. It is usable for many applications, but still of course not nearly as good as the full NTPv4. Regards, Ryan _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
