ALL COMPETITION STUDY MATERIALS

What is OSI model ? Explain the Layers of OSI model with diagram . What is OSI model? The OSI model (Open System Interconnection) model defines a computer networking framework to implement protocols in seven layers. A protocol in the networking terms is a kind of negotiation and rule in between two networking entities. Layers of OSI model: Physical layer The Physical layer is also called as the Layer 1. Here are the basic functionalities of the Physical layer: ·        Responsible for electrical signals, light signal, radio signals etc. ·        Hardware layer of the OSI layer ·        Devices like repeater, hub, cables, ethernet work on this layer ·        Protocols like RS232, ATM, FDDI, Ethernet work on this layer Data Link layer The data link layer is also called as the Layer 2 of the OSI model. Here are the basic functionalities of the data link layer: ·        Responsible for encoding and decoding of the electrical signals into bits. ·

    ➤➤➤Computer - Networking computer network :  A computer network   is a system in which multiple computers are connected to each other to share information and resources.  Characteristics of a Computer Network ·       Share resources from one computer to another. ·       Create files and store them in one computer, access those files from the other computer(s) connected over the network. ·       Connect a printer, scanner, or a fax machine to one computer within the network and let other computers of the network use the machines available over the network. Following is the list of hardware's required to set up a computer network. Network Cables Distributors Routers Internal Network Cards External Network Cards Network Cables : Network cables are used to connect computers. The most commonly used cable is Category 5 cable RJ-45. Distributors : A computer can be connected to another one via a serial p