Network Layer(Layer 3): It is responsible for the source-to-destination delivery of packets across multiple links(networks).It is also responsible for structuring and managing a multi-node network, including addressing, routing, and traffic control. Functions include: Logical Addressing: IP addressing is defined at the Network Layer of the OSI model. This layer adds a header to the packet coming from the upper layer that, among other things, indicates the logical addresses of the sender and receiver. IP addressing is also known as logical addressing. Routing: When independent networks are connected together to create a large network, the connecting devices(routers/gateways) route the packets to their final destination. The decision which route/path should be followed to reach from source to destination is handled by the network layer.