[ntp:questions] high precision tracking: trying to understand sudden jumps

David Woolley david at ex.djwhome.demon.co.uk.invalid
Mon Mar 31 18:18:49 UTC 2008

Heiko Gerstung wrote:

> time has passed without the signal coming back. This results in the time 
> server replying with stratum 12 (for example) after a while and ensures 
> that everybody has the same time, although it might be wrong. If a user 
> does not want that, they can simply set the local clock stratum to 15 
> and the server will not be accepted anymore.
> Can you please let me know why you consider this a "bad implementation"?

Because the protocol fails to signal the loss of the time source 
properly when one has a local clock configured.  As such, I believe that 
enabling a local clock should always be an opt in choice.  Basically, 
when it falls back to the local clock, root dispersion goes to zero, 
when the true situation is that root dispersion is growing without bound.

Things can go seriously wrong if there is more than one local clock 
source on a network, as it becomes possible for them to outvote the real 

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