Re: [chrony-dev] [GIT] chrony/chrony.git branch, master, updated. 2.4-9-g6cd5583

[Bill Unruh <unruh@xxxxxxxxxxxxxx>]

Is there some way to automate the determination of the best offset and slope
correction to apply due to network assymetries. If one plots the offset vs the
delay, one often gets a scatter plot in which there is a definite slope to the
result, suggesting that there is a persistant assymmetry to the round trip
time (see the scatter plots in 
www.theory.physics.ubc.ca/chrony/chrony.html
Note that in some of the cases, one event with a huge offset will make the plot a bit useless, 
but in general, it seems that most of the variation in the round trip time
takes place on one of the legs of the trip.
Ie, if one took out the slope, one would reduce the uncertainty by a factor of
2 or so. (Ie, actual offset = offset - .5 (roundtrip-minroundtrip)  for example.)

Of course for some there seems to a reasonable probability that it is on the
other leg of the roundtrip that the delay occurs, so one would have to be
careful, especially if which leg the delay occured on varied from time to
time.





On Tue, 28 Jun 2016, git@xxxxxxxxxxxxx wrote:

>    ntp: add offset option
>
>    Add offset option to the server/pool/peer directive. It specifies a
>    correction which will be applied to offsets measured with the NTP
>    source. It's particularly useful to compensate for a known asymmetry in
>    network delay or timestamping errors.

--
To unsubscribe email chrony-dev-request@xxxxxxxxxxxxxxxxxxxx with "unsubscribe" in the subject.
For help email chrony-dev-request@xxxxxxxxxxxxxxxxxxxx with "help" in the subject.
Trouble?  Email listmaster@xxxxxxxxxxxxxxxxxxxx.