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CS4461: Difference between revisions
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Purpose: To move a datagram over an individual link. The link layer has the end to end job of moving network layer datagrams over a ''single link'' in the path.
Possible services offered by a link-layer protocol include:
-Framing: Encapsulate the network-layer datagram within a link-layer frame
-Link Access: A medium access control (MAC) protocol specifies the rules by which a frame is transmitted onto the link.
-Reliable Delivery: When a protocol provides a reliable delivery service it guarentees to move each network-layer datagram across the link without error
-Flow Control: The nodes on each side of a link have a limited amount of frame buffering capacity.
-Error Detection: A node's receiver can incorrectly decide that a bit in a frame is zero when it was transmitted as a one and vice versa.
-Error Correction: Receiver not only detects whether errors have been intorduced in the frame but also determines exactly where in the frame the errors have occured.
-Half-duplex and full-duplex: With full-duplex the nodes at both ends of a link may transmit packets at the same time.
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