[ntpwg] ntpwg Updated NTPv4 Protocol Specification/timestamplocation

[David L. Mills]

TOdd,

No, no, no... The goal was never, never even since the 1979 ancestor of 
NTP, to set the clock relative to the transport medium or any capture 
point of the packet in flight.

THE GOAL OF NTP IS TO MINIMIZE THE TIME DIFFERENCE BETWEEN THE CLIENT 
CLOCK AND THE SERVER CLOCK.

With due and kind respect, have you been reading my messages?

The current discussion about the boys and girls is not about defining 
capture points for the NTP PDU but to demonstrate some design goals and 
rules that the operating system and hardware can use to optimize the 
accuracy. For my part these are not an integral component in the 
specification; others may disagree. A discussion on these points might 
well become and appendix to the specification in the form of best 
practices, but the implementer can choose or not choose one or the other 
without violating the specification.

Dave

> Q:
> Wasn't the original goal to assign an "instant in the NTP 
> packet-receipt process" which would indicate the specific time 
> represented in the packet-structure itself?
>
> Todd
> ----- Original Message ----- From: "STUART VENTERS" 
> <stuart.venters at adtran.com>
> To: <mills at udel.edu>
> Cc: <ntpwg at lists.ntp.org>
> Sent: Wednesday, February 06, 2008 3:55 PM
> Subject: Re: [ntpwg] ntpwg Updated NTPv4 Protocol 
> Specification/timestamplocation
>
>
>> Dave,
>>
>>>> In the famous equation you cite, add one second on the path from t1 to
>>>> t2 and a corresponding second on the path from t3 to t4. The 
>>>> additional
>>>> second cancels out. offset = {[(t2 + D) - t1] + [t3 - (t4 + D)]} / 2
>>>
>>
>> That does not compute.
>>  In your equation, D delays the receive timestamps (T2 and T4)
>>  In the example, D delays Sue's timestamps (T1 and T4)
>>
>> I fear the question stack has pushed too deep to ever pop out to the 
>> original goal.
>>  (IE. Understanding why CP1 and CP2 are (or are not) a necessary part 
>> of the spec.)
>>
>> 73's,
>>
>> Stuart
>> -.-. .-. -
>>
>>
>> ps, If anyone would like to call and help me understand, my office 
>> phone number is (256) 963-8719.
>> _______________________________________________
>> ntpwg mailing list
>> ntpwg at lists.ntp.org
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>
>