The SIM monitoring system includes one of the Gaithersburg, MD NTP servers, 129.6.15.28, http://132.163.4.82/scripts/ow_ntp.exe?2016041602001 See "Automated Clock Comparisons and Time Scale Generation in the SIM region", http://tf.boulder.nist.gov/general/pdf/2586.pdf for details.
On Sat, Apr 16, 2016 at 8:43 AM, Kurt Roeckx <[email protected]> wrote: > On Sat, Apr 16, 2016 at 03:07:45PM +0200, Max Grobecker wrote: > > Hi, > > > > Am 16.04.2016 um 10:20 schrieb Hal Murray: > > > The monitoring system is on the west coast, Los Angeles. The NIST > servers > > > are on the east coast. My guess would be asymmetric routing explains > the > > > offset in the monitoring graphs. > > > > Routing should be totally insignificant to the NTP offsets, since NTP > measures > > the packet round-trip and recalculates the timestamps received. > > So, even if the packet needs thousands of milliseconds to get around the > internet, > > your time should be +/- 1ms accurate. > > That only works properly if the delay is the same the same in both > direction. Sometimes you can get a totally different route back > and so also have a total different delay. NTP has no way to > compensate for that. > > > Kurt > > _______________________________________________ > pool mailing list > [email protected] > http://lists.ntp.org/listinfo/pool > _______________________________________________ pool mailing list [email protected] http://lists.ntp.org/listinfo/pool
