‫The next layer is the third layer of the U.S. reference model.
‫The network layer.
‫The network layer provides the means of transferring variable length network packets from a source to
‫a destination host via one or more networks.
‫In other words, the network layer is responsible for packet forwarding, including routing through
‫intermediate routers.
‫Within a service layering semantics of the USA Network architecture, the network layer responds to
‫the service requests from the transport layer and issue service requests to the data link layer.
‫So here are the functions of the network layer.
‫Connection, lost communication.
‫For example, IP is connections in that data packet can travel from the sender to a recipient without
‫the recipient having to send an acknowledgement.
‫Connection oriented protocols exist at other higher levels of the U.S. model.
‫Host addressing.
‫Every host in the network must have a unique address that determines where it is on the internet.
‫Addresses are known as IP addresses, right?
‫Message forwarding since many networks are partitioned into sub networks and then connect to other networks
‫for wide area communications networks use specialized hosts called gateways or routers to forward packets
‫between networks.