Which one of the following is not a function of network layer?
|None of the mentioned
The correct answer is :A
- 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 assumes a pivotal position between the transport layer and the data link layer within the OSI model. Its principal role revolves around orchestrating the transit of network packets from their origins to their designated destinations, achieved by establishing comprehensive end-to-end pathways connecting them. This function is executed through the encapsulation of data, received from the transport layer, into discrete units referred to as datagrams. These datagrams encompass essential elements such as source and destination addresses, alongside supplementary metadata.
- Once a datagram is composed, the network layer undertakes the task of discerning the most optimal trajectory for its journey to the intended endpoint. This intricate process is reliant on routing protocols, which facilitate the construction and maintenance of routing tables housing vital insights regarding available network routes. These routing tables empower the network layer to make judicious decisions in selecting the most suitable path for the datagram. Factors weighed in this determination encompass aspects such as network congestion, link stability, and cost considerations.
- A fundamental responsibility of the network layer also encompasses congestion control. This imperative function serves to uphold network performance by averting overwhelming traffic that could precipitate performance deterioration or, in extreme cases, network collapse. The network layer effectively undertakes this duty by vigilant traffic monitoring and subsequent regulation of packet flow. For instance, it may enact measures to moderate the pace of packet transmission from specific sources to forestall inundating the network with an excessive volume of data.
- 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.