The network layer provides routing and related functions that enable multiple data links to be combined into an internetwork. This is accomplished by the logical addressing (as opposed to the physical addressing) of devices. The network layer supports both connection-oriented and connectionless service from higher-layer protocols. Routing protocols, routed protocols, and other types of protocols are implemented at the network layer.
Some common routing protocols include Border Gateway Protocol (BGP), which is an Internet interdomain routing protocol; Open Shortest Path First (OSPF), which is a link-state, interior gateway protocol developed for use in Transmission Control Protocol/Internet Protocol (TCP/IP) networks; and Routing Information Protocol (RIP), which is a TCP/IP routing protocol that uses hop count as its metric.
Was this article helpful?