Short for Data Link Control, the second lowest layer in the OSI Reference Model. Every network interface card (NIC) has a DLC address or DLC identifier (DLCI) that uniquely identifies the node on the network. Some network protocols, such as Ethernet and Token-Ring use the DLC addresses exclusively. Other protocols, such as TCP/IP, use a logical address at the Network Layer to identify nodes. Ultimately, however, all network addresses must be translated to DLC addresses. In TCP/IP networks, this translation is performed with the Address Resolution Protocol (ARP). For networks that conform to the IEEE 802 standards (e.g., Ethernet ), the DLC address is usually called the Media Access Control (MAC) address.