The number of packets, delivered by this sub-layer to a
higher (sub-)layer, which were not addressed to a multicast
or broadcast address at this sub-layer. This object is a
64-bit version of ifInUcastPkts.
Discontinuities in the value of this counter can occur at
re-initialization of the management system, and at other
times as indicated by the value of
ifCounterDiscontinuityTime.