The following table contains NTP state variables
used by the NTP clock filter and selection algorithms.
This table depicts a shift register. Each stage in
the shift register is a 3-tuple consisting of the
measured clock offset, measured clock delay and
measured clock dispersion associated with a single
observation.
An important factor affecting the accuracy and
reliability of time distribution is the complex of
algorithms used to reduce the effect of statistical
errors and falsetickers due to failure of various
subnet components, reference sources or propagation
media. The NTP clock-filter and selection algorithms
are designed to do exactly this. The objects in the
filter register table below are used by these
algorthims to minimize the error in the calculated
time.