Which OSI layer is designated as the Network Layer?

The Network Layer is designated as Layer 3 of the OSI model. This layer is crucial for the function of network communications, as it is responsible for the logical addressing and routing of data packets. Specifically, it determines how data is sent from the source to the destination across multiple networks.

At this layer, protocols such as Internet Protocol (IP) operate, allowing devices to communicate with one another regardless of their physical location on the network. Layer 3 provides important functions like traffic routing, packet forwarding, and fragmentation. These responsibilities are essential for enabling connectivity and efficient data transfer between devices on an interconnected network, which is a foundational concept in communication and network security.

The other layers do not have the same functions that characterize the Network Layer. Layer 2, for instance, deals with data link functions such as framing and physical addressing, while Layer 4 manages transport layer functions, including flow control and error recovery. Layer 5 is associated with the session layer, which controls the sessions between computers. Each of these layers plays a specific role, but it is Layer 3 that pertains to the network aspects of data transfer.