data link layer
     
         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)