A MAC unit is provided that processes the flow of data between a higher protocol-layer unit and a physical-layer control unit of a network communications component. The MAC unit includes a first processor that receives high-level data units from the higher protocol-layer unit and generates outgoing MAC protocol-data units therefrom. The MAC unit also includes a second processor that receives outgoing MAC protocol-data units generated by the first processor and generates outgoing FEC blocks therefrom for outputting to the input port of the physical-layer control unit. In addition the MAC unit includes a MAC-PDU reception buffer accessible by the first and second processors, the second processor storing incoming MAC protocol-data units in the MAC-PDU reception buffer, and the first processor reading incoming MAC protocol-data units from the MAC-PDU reception buffer.