[time-nuts] Need Time Help
tic-toc at bodosom.net
Tue Oct 4 23:05:21 EDT 2016
On Tue, Oct 4, 2016 at 9:05 PM, Chris Albertson <albertson.chris at gmail.com>
> The problem, I think with your Internet sync's NTP servers is you are only
> using one server S. The most common practice is to use 3 to 5 with 5 being
> about the right number. If you get Ntp enough Internet servers to work
> with it can detect problem like asymmetric path lengths which I'm sure is
> you problem.
NTPD cannot find asymmetric delays. The NTP protocol assumption continues
to be symmetric delays with random delay spikes that can discarded.
However despite that the resultant jitter and offset from asymmetry should
be on the order of milliseconds (O(1ms)). As the OP has seen not using PPS
swamps all other errors -- NMEA (et.al.) errors are O(100ms) unless you
have a well designed unit e.g. a JL Fury.
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