[ntp:questions] time.windows.com

David L. Mills mills at udel.edu
Tue Oct 9 23:42:54 UTC 2007


Goaded by an earlier comment that the Windows default time server 
time.windows.com was flawed, I cranked up an association and here's what 
happened. First, it now does the client/server protocol correctly. 
Second, the packet drop rate is over 50 percent(!). Third, it is not a 
primary serer; it chimes a primary server at MIT synchronized by CDMA. 
Fourth, the roundtrip delay from Delaware is over 150 ms, which as the 
net flies is further than Alaska. The time is not too bad, about +-7 ms 
with jitter occasionally over 200 ms(!).

I'm happy to find this behavior. It's hard to find behavior as bad as 
this to test the NTP mitigation algorithms. The clock filter algorithm 
and popcorn spike suppressor work really well to sift +-7 ms in 200-ms 


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