Which one of the following is not a function of network layer?

Which one of the following is not a function of network layer?

The correct answer is :A

Explanation :

The network layer plays a crucial role in facilitating communication between devices on a computer network. It accomplishes this task by providing logical addressing, routing, and congestion control services. Logical addressing allows devices to identify each other on the network using unique identifiers, such as IP addresses. Routing involves the selection of optimal paths for data packets to travel from the source to the destination. Congestion control, on the other hand, helps to prevent network congestion by regulating the flow of packets through the network.
Transmission, however, is not a function of the network layer. Transmission refers to the physical movement of data over the network, which is handled by the data link layer and physical layer in the OSI model. The data link layer is responsible for transmitting data frames between nodes on the same network, while the physical layer deals with the transmission of bits over the physical medium.
The network layer is located between the transport layer and the data link layer in the OSI model. Its primary function is to transport network packets from their source to their destination by establishing end-to-end paths between them. The network layer accomplishes this task by encapsulating data received from the transport layer into packets called datagrams, which contain source and destination addresses, as well as other metadata.

Once a datagram has been created, the network layer determines the optimal path for it to reach its destination. This process involves the use of routing protocols, which help to build and maintain routing tables that store information about the available network paths. The network layer uses this information to select the best path for the datagram based on factors such as network congestion, link reliability, and cost.
Congestion control is another important function of the network layer. It helps to ensure that the network is not overwhelmed with traffic, which can lead to performance degradation or even network failure. The network layer accomplishes this task by monitoring the traffic on the network and adjusting the flow of packets accordingly. For example, it may slow down the transmission of packets from a particular source to prevent it from flooding the network.
In summary, while transmission is not a function of the network layer, the network layer plays a critical role in facilitating the transport of data packets across a computer network. It does this by providing logical addressing, routing, and congestion control services, and is essential for ensuring the efficient and reliable operation of computer networks.