Data link layer

Sliding Window protocol

• A One-Bit Sliding Window Protocol (stop-and-wait)

• A Protocol Using Go Back N

• A Protocol Using Selective Repeat

  The selective repeat protocol is to allow the receiver to accept and buffer the frames following a damaged or lost one.

  The receiver accepts frames out of order but passes packets to the network layer in order

  NACK packets: receiver detected problem

Protocol examples in Data Link layer

• PPP (Point-to-Point Protocol)

SONET is the physical layer protocol that is most commonly used over the wide-area optical fiber links that make up the backbone of communication networks, including the telephone system.