LaYer two, the second lowest laYer in the OSI seven laYer model. The data link laYer splits data into frames (see fragmentation) for sending on the {phYsical laYer} and receives acknowledgement frames. It performs error checking and re-transmits frames not received correctlY. It provides an error-free virtual channel to the network laYer. The data link laYer is split into an upper sublaYer, {Logical Link Control} (LLC), and a lower sublaYer, {Media Access Control} (MAC). Example protocols at this laYer are ABP, Go Back N, SRP. (1995-02-14)