Accepts data packets of arbitrary length from the Network Layer.

Accepts the address of an adjacent node to which it is to transmit the data. An adjacent node is one connected to the sending node by a Physical Layer link.

Controls access to a shared Physical Layer medium, such as a broadcast network.

Adds sequence information to the frames. If they get out of sequence during error recovery, they can be put back into the right sequence by the receiving peer process.

Adds error detection and correction codes to the frames so the receiving peer process can tell when an error has occurred. (Remember that the Physical Layer cannot detect data errors.)

Adds handshaking information to the data frames so it can cooperate with the peer process to correct problems, such as a frame that is completely lost.

Handshakes with its peer to ensure that the complete packet is received correctly.

Uses the services of the Physical Layer to transmit frames.

During transmission, does not send frames to the Physical Layer at a faster rate than the receiving Data Link Layer process can handle them.

Receives bits passed up from the Physical Layer and interprets groups of bits as frames.

Checks each frame for errors. If errors are found, it takes corrective measures, such as requesting a retransmission from the transmitting peer process.

Handles problems, such as missing frames, through handshaking with its peer process.

Puts the frames back in the correct sequence to reconstruct the packet.

Passes each decapsulated packet up to the Network Layer.