This module examines peer-to-peer protocols and service models. Importantly, it examines three automatic repeat request (ARQ) protocols that provide reliable data transfer service.

This module introduces TCP that uses ARQ techniques to provide reliable stream service and flow control end-to-end across connectionless packet network. It also examines two framing techniques that are used to identify the boundaries of frames of information within a digital bit stream, and discusses two data link control standards in widespread use.

This module discusses the need for medium access control (MAC), and introduces representative random access and scheduling MAC protocols - including the carrier-sense multiple access with collision detection CSMA-CS protocol which forms the basis for the Ethernet LAN standard. It also shows the impact of delay-bandwidth product on protocol performance.

This module discusses the structure of the frames used in LANs, and introduces several important LAN standards, including the IEEE 802.3 Ethernet LAN and IEEE 802.11 wireless LAN. Furthermore, the MAC protocols associated with each LAN standard are also described.