This read-only PerfCounter64 counts Bytes Red Frame Dropped by this traffic port's QoS shaper as retained in the history bin, the archived counterpart to cmTrafficPortQosShaperStatsBREDD. It gives an administrator historical evidence of how much out-of-profile byte volume this specific physical port has been discarding over time. For example, a steadily increasing trend across cmTrafficPortQosShaperHistoryBREDD bins for one port would support a recommendation to the customer to upgrade their contracted rate.