Notes on Network Layer

What Is an OSI Model?

Before starting off with the network layer, let us know what an OSI model is. The Open System Interconnection model, or OSI model, in short, is a system that has been created to facilitate an effective communication process between diverse network services. It has been standardised and implemented by international protocols.

The OSI model has been divided into seven layers on the basis of the functions assigned to each layer. The network layer comes at position number three in an OSI model.

Network layer:

The network layer is the most important layer of the OSI model. It is involved in the real-time transferring and processing of data. It functions at both the source and destination of the data to be transferred.

How does a Network layer work?

The network layer converts data into small forms called packets. The data packets are encapsulated after receiving them from the transport layer. The packets are decapsulated after reaching the destination. In case the data packet is too large to be transported across, it is broken down into smaller packets or fragments to facilitate the easy flow of data.

The network layer majorly uses the method of routing, which is referred to as the process of using the most feasible pathway among the multiple available routes to deliver the data.

It has a system of inclusion of physical addresses of both the source and the destination, thereby making it easier to address the details of the data route easily.

Some of the services by  network layer are:

1. Sense of Security: A network layer follows the encryption route end-to-end by the addition of a session method between the source and the receiver. The session method is key to providing maximum communication in a secure way by allotting a particular time period for the data transfer.
2. Traffic control: By creating optimal “virtual circuits” with the help of the routing method, the network layer minimises congestion and ensures guaranteed data transfer.
3. Control of Data Flow: By optimising the virtual routes of communication, it prevents an overload of data by regulating the data load within the source and destination. Such situations arise in case of a greater rate of data products from the source side, but the destination does not have the adequate speed for receiving it, resulting in an overload of data for the receiver’s end.
4. Control of Errors: It is not a very effective service provided by the network layer. An example includes the case of transportation of a large amount of data. As stated earlier, the large data packets are broken down into smaller bits for easier data transfer. However, with this breakdown of data arises the issue of errors, as there is no feasible way of checking the errors at the receiver’s end due to the breakdown of data.

Advantages of a network layer:

1. It reduces the network traffic by using the router method, thereby optimising the pathways of communication.
2. The packet system of data handling ensures easy transportation of the data across.

Conclusion:

In this article, we saw a brief overview of an OSI model. With this model, the facilitation of communication between various network systems becomes easier due to the implementation of international protocols. The network layer of the OSI model is the most important layer of this system. The network layer works both from the source as well as the destination ends by real-time processing and transferring of data. It uses the method of routing for optimisation of effective data transfer and to prevent network traffic. By converting data into packets and also breaking it down in cases of large amounts of data, it facilitates easy transportation of data across.