A count of the number of frames that were dropped by the OAM multiplexer. Since the OAM mulitplexer has multiple inputs and a single output, there may be cases where frames are dropped due to transmit resource contention. This counter is incremented whenever a frame is dropped by the OAM layer. When this counter is incremented, no other counters in this MIB are incremented. Discontinuities of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of the ifCounterDiscontinuityTime.