Network access controller

Definition
A network access controller is

"[a] physical interface to a distributed switching network. It uses a common medium that operates throughout at the same digital transfer rate using arbitration (e.g., token or carrier sense) for transmission. Independently from any other, it selects data packets or data groups (e.g., IEEE 802) addressed to it. It is an assembly that can be integrated into computer or telecommunications equipment to provide communications access."