Working of LAN, OSI Model, OSI

How does a LAN Work?

The year 2000 saw a boom in the Information technology. Rather one can call it as, the revolution in the digital age. Computers were much advanced and there was a need for more advanced networking. Network and  networking are two different terms. A group of computers attached together is called as 'Network'. Whereas, networking takes place only when the computers share their resources with each other. The process of sharing of files, resources and data from a computer to another computer is called as 'Networking'. 

But how does a computer share the resources within a click?

For this, there must be some Protocols or methods for a computer to operate within a network. The Set of protocols designed under OSI model allow the computer to share. OSI stands for Open Systems Intercommunication.The objective of OSI model is to display the communication facilities between different systems without making any changes to the logic of hardware and software. The OSI is not a protocol rather it is a model for understanding and designing a network architecture that is flexible and vigorous.

Operation of Networking:
Lets understand the terminology and working behind the network.

The OSI model consists of  7 layers. These 7 layers define the various protocols in a series. 

The recipient computer requests the server for an operation. The server then undergoes ahead to serve the request.  Thus, the 7 layers of OSI model allow the server and recipient to make a successful sharing.

Below is the diagram of OSI model.

1. Physical Layer: The physical layer defines the hardware. All the hardware devices relating to a computer are recognized in this layer. The physical layer defines the protocol to establish and close a connection between two connected computers.  

2. Data Link Layer: This is the second layer.  The data link layer provides computer to computer data transfer. The MAC and LLC are two sublayers that operate within data link layer. MAC stands for media access control and LLC stands for Logical link layer.

3. Network Layer: The network layer is the third layer which provides functional and procedural means of transmission of data from computer to computer. The data is transmitted in form of fixed packets called as data packets. Hence, data is prepared in the form of packets in this layer.The network layer does not support guarantee successful transmission.

4. Transport Layer: This is the fourth layer. The purpose of transport layer is to transmit the data packets to the recipient computer. The TCP/IP protocol works under this layer and is responsible for the transmission. The transport layer is responsible for successful transmission of data packets.

5. Session Layer: This is the fifth layer of OSI model. The session layer controls the connections i.e. sharing between two computers.The session layer works as an intermediator deciding the flow of packet transmission.

6. Presentation Layer: This is the sixth layer of the OSI model. The function of this layer is to map the semantics and relevancy of the data transmitted on the end user. Thus, the presentation layer transforms the data that the application accepts.

7: Application Layer: The application layer is the data close to the end-user. The user interaction is direct and the user can view the processed information. The responsibility of the application layer is synchronization of the processed information.

Conclusion: The OSI model is the basis of the networking between computer and computers. This technology is the basic platform for any resource sharing in the digital age. Thus, a LAN work efficiently only if there is synchronization among all the layers of the OSI Model.