In article <[EMAIL PROTECTED]>, [EMAIL PROTECTED] wrote: > (a) The difference in time between the incorrect time on a local > server, and the correct time on a correct NTP server. > or
It's closer to this one, but it is not this one. In the peers output, it is the difference between the estimated value of the software clock on the local machine and estimated value of the software clock on the server in question, allowing for round trip delay, but not for past history. As one normally expects to be able to read the local clock more accurately than the server clock (NB this does not apply to W2003 latest service pack W32Time as a client to the reference implementation on Windows or many Unix(like) boxes), the normal state will be that the local time is a better estimate of true time than the server time. The local time will only be the more "incorrect" time during initial convergence (and even then there was a big debate, about a couple of weeks ago, as to whether ntpd could actually avoid this situation in cases where it knew it to be true). (Actually, it could be wrong in phase due to assymmetric delays, as well, but those would not be visible in the reported offset.) The offset actually used for the disciplining the local clock is, a weighted average of the, assumed, best value from several of the servers. > (b) The time delay (caused by latency etc) to receive the correct time > from an NTP server. Ie By the time the local server receives the > "correct time", this "correct time" value is now slightly old. Noting the above caveat about the local time being likely to be the more correct, the delay parameter gives half the maximum error due to this, give or take the clock reading precisions. (Noting that W32Time on anything except the current SP of W2K3 does not implement NTP, the reason that the W32Time implementation of NTP may be less correct than the server is that it only reads the software clock to a one tick resolution, whereas the reference implementation interpolates, using the cycle counter on the CPU.) _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
