Data Link Control
OSI model
In the OSI networking model, Data Link Control (DLC) is the service provided by the data link layer.
Network interface cards have a DLC address that identifies each card; for instance, Ethernet and other types of cards have a 48-bit MAC address built into the cards' firmware when they are manufactured.
Network protocol
The same initialism, standing for the same phrase, is also a network protocol in its own right, comparable to better-known protocols such as TCP/IP or AppleTalk. DLC is a transport protocol used by IBM SNA mainframe computers and peripherals and compatible equipment. In PC networking, it is typically used for communications between network-attached printers and PCs and servers, for example by HP in their JetDirect print servers. While it was widely used up until the time of Windows 2000, the DLC protocol is no longer included in Windows XP, but available for download [1].