Link level
In computer networking, in the hierarchical structure of a primary or secondary station, link level is the conceptual level of control or data processing logic that controls the data link.
Link-level functions provide an interface between the station high-level logic and the data link. Link-level functions include (a) transmit bit injection and receive bit extraction, (b) address and control field interpretation, (c) command response generation, transmission and interpretation, and (d) frame check sequence computation and interpretation.
References
This article incorporates public domain material from the General Services Administration document: "Federal Standard 1037C".