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‫The next layer is the third layer of the U.S. reference model.

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‫The network layer.

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‫The network layer provides the means of transferring variable length network packets from a source to

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‫a destination host via one or more networks.

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‫In other words, the network layer is responsible for packet forwarding, including routing through

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‫intermediate routers.

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‫Within a service layering semantics of the USA Network architecture, the network layer responds to

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‫the service requests from the transport layer and issue service requests to the data link layer.

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‫So here are the functions of the network layer.

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‫Connection, lost communication.

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‫For example, IP is connections in that data packet can travel from the sender to a recipient without

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‫the recipient having to send an acknowledgement.

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‫Connection oriented protocols exist at other higher levels of the U.S. model.

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‫Host addressing.

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‫Every host in the network must have a unique address that determines where it is on the internet.

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‫Addresses are known as IP addresses, right?

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‫Message forwarding since many networks are partitioned into sub networks and then connect to other networks

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‫for wide area communications networks use specialized hosts called gateways or routers to forward packets

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‫between networks.