Network Layer in OSI Model in Computer Networks

In this tutorial, we are going to learn about network layer in OSI model.

The network layer (Layer 3) is in charge of delivering data packets from their source to their destination through numerous hops (nodes). It’s in charge of the subnet’s operations. The Network Layer in OSI Model converts the logical addresses to physical addresses. It determines the path from the source to the destination. It also handles traffic issues including switching and routing, as well as data packet congestion. The network layer’s primary function is to transport data packets from one host to another.

Functionalities of Network Layer in OSI Model:

1. Routing :

When a packet arrives on the router’s input connection, this layer forward it to the router’s output link. A packet sent from S1 to R1 must, for example, be sent to the next router on the path to S2.

2. Logical Addressing :

Physical addressing is implemented by the data connection layer, whereas logical addressing is implemented by the network layer. To distinguish between the source and destination systems, logical addressing is undoubtedly useful. The network layer adds a header to the packet that includes both the sender and receiver’s logical addresses.

3. Internetworking :

Not to mention that the network layer’s primary function is to enable logical connections between different types of networks.

4. Fragmentation :

Fragmentation is basically the process of breaking down packets into their smallest individual data units and transporting them across several networks.

Services Provided by Network Layer in OSI Model:

Guaranteed delivery

Guaranteed delivery with bounded delay

In-Order packets

Guaranteed max jitter

Security services.

Network Layer in OSI Model and TCP/IP Model :

The Internet’s protocols are described under the TCP/IP model. Above the connection layer in the TCP/IP model, there is the Internet layer. There is confusion between the TCP/IP Internet layer and the OSI network layer in textbooks and other secondary sources. The allowable properties of protocols placed into these tiers are different in the two models, therefore this comparison is deceptive. The TCP/IP Internet layer is generally a subset of the network layer’s capability. It describes only one sort of network design, the Internet.