Answer:
Network layer
Explanation:
Network layer is used when devices from different network involves communication.So,network layer is not required if devices communicate in a same network.
The network layer is concerned with the selection of network paths.
The network layer is the layer in OSI Model. This layer provides data routing paths for communication. Data is transferred on nodes via packets in an order controlled by the network layer.
This layer includes hardware devices such as bridges, firewalls ,routers and switches, but it effectively generates a logical image of the most effective communication path and implements it with a physical medium.
