(PDU) A packet of data passed across a network. The term
implies a specific layer of the OSI seven layer model and a
protocol data unit
The technical name of a frame of data transmitted over the data link layer (layer 2) in a communications network. Ethernet and Token Ring are examples of this layer. Many people neither use the term PDU nor the term frame, but call every unit of data traveling over a network a "packet." See OSI model and packet.