Lei wrote: > In RFC 2030(written by Prof. D.Mills), we have roundtrip delay time > formula as follows: > > d = (T4 - T1) - (T2 - T3) .................(1) > > However, IMHO, it should be > > d = (T4-T1) - (T3 - T2)....................(1)' > > using which we can get > > t = ((T2 - T1) + (T3 - T4)) / 2 ...........(2) > > successfully by inserting d into the following formula > > t = T3 + d/2 - T4. ...........................(3) > > But if we use d as in formula (1), we can not get (2). > > Anyone has an idea? :) > > Thanks. > -Lei
This was in error in the RFC. The NTP v4 draft shows it correctly (Section 8): The four most recent timestamps, T1 through T4, are used to compute the offset of B relative to A theta = T(B) - T(A) = 1/2 * [(T2-T1) + (T3-T4)] and the round trip delay delta = T(ABA) = (T4-T1) - (T3-T2). Danny -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
