MAC Frame Format
The unit of transfer on the MAC sublayer is called a MAC frame. The format differs for the various protocols. In general, the format is similar to the one in the picture.
In most data link control protocols, the DLC is responsible for detecting and recovering from errors. These two functions are split between the MAC and LLC layers. The MAC layers detects and discards any frames that are in error. Optionally, the LLC keeps track of which frames have been received and retransmits missing frames,