The time between rate computations. This global value
applies for the computation of all URPF rates, global
and per-interface.
When the value of cipUrpfComputeInterval is changed,
the interval in-progress proceeds as though the value
had not changed. The change will apply to the length
of subsequent intervals.
The cipUrpfComputeInterval must be less than or equal
to the cipUrpfDropRateWindow.