What is Data-Link layer? - Definition from Whatis.com

The Data-Link layer is the protocol layer in a program that handles the moving of data in and out across a physical link in a network. The Data-Link layer is layer 2 in the Open Systems Interconnect (OSI) model for a set of telecommunication protocols.

The Data-Link layer contains two sublayers that are described in the IEEE-802 LAN standards:

  • Media Access Control (MAC)
  • Logical Link Control (LLC)

The Data-Link layer ensures that an initial connection has been set up, divides output data into data frames, and handles the acknowledgements from a receiver that the data arrived successfully. It also ensures that incoming data has been received successfully by analyzing bit patterns at special places in the frames.

This was last updated in June 1997

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