1. A method of transmitting digital data over a network comprising: receiving a plurality of packet data units; identifying at least two of the plurality of packet data units that have a same aggregation identifier; forming an aggregate packet from the at least two of the plurality of packet data units wherein the aggregate packet comprises a media access control header; calculating a first checksum for the aggregation header; comparing the first checksum to a second checksum that is received in an aggregation header of the aggregate packet; determining the presence of an original frame check sequence bit in the media access control header; and transmitting the at least two of the plurality of packet data units without modifying the frame check sequences if the second checksum is found to be correct to at least one destination.