This counter tallies the number of received frames that this PM instance discarded on the way in, as stated in the MIB description. Reading this alongside cienaCesPmBasicRxTotalStatsBinBasicRxDroppedBytes lets an admin work out the average size of the discarded frames -- a high frame count with a low byte count usually means small control or voice-sized frames are the ones being dropped, which is far more disruptive to real-time traffic than losing an equivalent volume of large bulk-transfer frames. For example, 3,575 dropped frames in a single 15-minute bin on a VoIP-carrying pseudowire would translate into audible call-quality issues even though the aggregate byte loss might look small.