[ntp:questions] NTP tunning for OWD measurements
david at ex.djwhome.demon.invalid
Fri Oct 26 22:19:16 UTC 2012
pret3nder at gmail.com wrote:
> Also, I don't want to use NTP to directly measure the one-way delay, I have OWAMP
You can't stop it measuring the delay asymmetry! The trouble is you
will not have any way to obtain that value, which will tend to cancel
out the asymmetry measured by your primary tool, assuming it depends on
accurate time stamps!
> (more specifically perfSonar - http://www.internet2.edu/performance/pS-PS/)
> to do that for me.
The page is a commercial type hype, not a technical overview of the
algorithms used, but the only way I know of measuring one way delay is
synchronise the clocks somewhat better than the acceptable measurement
error, which you can't do if the synchronisation process is vulnerable
to the effects of the same delay asymmetry.
More information about the questions