On Tue, 28 Jan 2014 13:31:51 +0000, Charles Elliott wrote: > Discussion: > > It is definitely, definitely true that offset (error) is highly > correlated with the distance between the client and the server. For a > time, one of the stratum 2 servers in the USA State of New Jersey was > using a server at a technical university in Poland as a source of time. > When the New Jersey server was connected to a server in New York (maybe > 20-25 miles away), its time output was in sync with everyone else's, but > when it was connected to the one in Poland, its time was ~30 ms slower > than everyone else's. Perhaps the time it took the New Jersey server to > warm up its local DNS (or ARP???) to access the IP address of the Poland > server accounts for this error. Nothing or no one else has been able to > account for it. And I have checked the formulas for delay and offset in > the RFC and in the implementation in NTPD dozens of times and can find no > error (as long as the server and the client are relatively close (within a > few years) to each other in time).
That sounds more like a case of asymmetrical routing. I have seen that sort of behaviour in a case where path delay one way was ~40ms, and the return path over 200ms. -d _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
