Answer to Question #269687 in Computer Networks for Olwam

Question

Models are useful because they help us to understand difficult concepts and complicated systems. When it comes to networking, there are several models that are used to explain the roles played by various technologies and how they interact. The most popular and commonly used of these models is the Open Systems Interconnection (OSI) Reference Model. Discuss the OSI model in terms of the functions of the various layers that it is made up of. Make use of a diagram to explain the various layers.

Answer 1

OSI Model describes How information transforms from one software in one computer moves through a network to reach software in another computer. And it does this by breaking huge task of data communication into several seven different layers and given control of data being sent from one layer to another. This layers include Application, Presentation, Session, Transport, Network Data-Link and physical layer. The Application Layer closer to the end receives information directly from users and displays incoming data to the user. Presentation Layer represents the preparation or translation of application format to network format, or from network formatting to application format. When two computers or other networked devices need to speak with one another, a session needs to be created and it is done at Session layer. The Transport Layer deals with the coordination of the data transfer between end systems and hosts. Here at the Network Layer, this layer is responsible for packet forwarding, including routing through different routers while Data Link provides node-to-node data transfer and handles error correction from the physical layer. At the bottom is Physical Layer, which represents electrical and physical representation of the system.