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.

In networking and communications, the formats, codes and procedures for transmitting a unit of data (frame, packet) from one node to another. Known as a "layer 2 protocol," the data link protocol ...

Medium access control protocol data units are a package of data (group of data bits) that contain header, connection address and data protocol information that is used to control and transfer ...

Frame relay is a packet switching protocol for connecting devices on a Wide Area Network (WAN). Switched Multimegabit Data Services (SMDS) is a high-speed switched data communications service offered ...