[ntp:questions] A question about the NTP delay time formula

Lei juliettlay at gmail.com
Tue Jun 23 02:36:01 UTC 2009


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




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