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COMPUTER NETWORKING A computer network, often simply referred to as a network, is a collection of computersand devices interconnected by communications channels that facilitate communications and allows sharing of resources and information among interconnected devices.[1] Put more simply, a computer network is a collection of two or more computerslinked together for the purposes of sharing information
PROJECT-ON SETTING FOR NETWORKING OF FIFTY PC
Advantages of Computer Networks File Sharing Resource Sharing Increased Storage Capacity Increased Cost Efficiency
Disadvantages of Computer Networks • Security Issues • Rapid Spread of Computer Viruses • Expensive Set Up • Dependency on the Main File Server:
TYPES OF NETWORK • Peer-to-Peer Networking This is a simple network configuration that requires some basic know-how to set up. Each of the interconnected machines share dual capability and responsibility on the network. That is to say, that each machine serves a dual purpose or role, i.e. they are both clients and servers to some extent. • Client/Server Networks Server based networks, or client/server networks as they are properly called, has a machine at the heart of its operations called the server. A server is a machine that provides services over a network by responding to client requests. Servers rarely have individuals operating it, and even then, it is usually to install, configure or manage its capabilities. The server's essential role on the network is to be continuously available to handle the many requests generated by its clients.
OTHER TYPES OF NETWORK • LOCAL AREA NETWORK • METROPOLITEN AREA NETWORK • WIDE AREA NETWORK • CAMPUS AREA NETWORK • SYSTEM AREA NETWORK
DEVICES OF COMPUTER NETWORKING • Common basic networking devices: • Router: a specialized network device that determines the next network point to which it can forward a data packet towards the destination of the packet. Unlike a gateway, it cannot interface different protocols. Works on OSI layer 3. • Bridge: a device that connects multiple network segments along the data link layer. Works on OSI layer 2. • Switch: a device that allocates traffic from one network segment to certain lines (intended destination(s)) which connect the segment to another network segment. So unlike a hub a switch splits the network traffic and sends it to different destinations rather than to all systems on the network. Works on OSI layer 2. • Hub: connects multiple Ethernet segments together making them act as a single segment. When using a hub, every attached all the objects, compared to switches, which provide a dedicated connection between individual nodes. Works on OSI layer 1. • Repeater: device to amplify or regenerate digital signals received while sending them from one part of a network into another. Works on OSI layer 1
Other hardware for establishing networks or dial-up connections • Multiplexer: device that combines several electrical signals into a single signal • Network Card: a piece of computer hardware to allow the attached computer to communicate by network • Modem: device that modulates an analog "carrier" signal (such as sound), to encode digital information, and that also demodulates such a carrier signal to decode the transmitted information, as a computer communicating with another computer over the telephone network • ISDN terminal adapter (TA): a specialized gateway for ISDN • Line Driver: a device to increase transmission distance by amplifying the signal. Base-band networks only
CABLES USE FOR NETWORKING • Networking Cables are used to connect one network device to other or to connect two or more computers to share printer, scanner etc. Different types of network cables like Coaxial cable, Optical fiber cable, Twisted Pair cables are used depending on the network's topology, protocol and size. The devices can be separated by a few meters (e.g. via Ethernet) or nearly unlimited distances (e.g. via the interconnections of the Internet). • While wireless may be the wave of the future, most computer networks today still utilize cables to transfer signals from one point to another.[1]
THERE ARE THREE TYPES • Twisted pair • Twisted pair cabling is a form of wiring in which two conductors (the forward and return conductors of a single circuit) are twisted together for the purposes of canceling out electromagnetic interference (EMI) from external sources; for instance, electromagnetic radiation Twisted pair are classified into two types unshielded twisted pair shielded twisted pair from unshielded twisted pair (UTP) cables, and crosstalk between neighboring pairs.This type of cable is used for home and corporate networks utilising the RJ45 connector ends • Optical fiber cable An optical fiber cable is a cable containing one or more optical fibers. The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable will be deployed.
Coaxial cable • Coaxial cabling has a single copper conductor at its center. A plastic layer provides insulation between the center conductor and a braided metal shield (See fig. 3). The metal shield helps to block any outside interference from • Although coaxial cabling is difficult to install, it is highly resistant to signal interference. In addition, it can support greater cable lengths between network devices than twisted pair cable. The two types of coaxial • Thin coaxial cable is also referred to as thinnet. 10Base2 refers to the specifications for thin coaxial cable carrying Ethernet signals. The 2 refers to the approximate maximum segment length being 200 meters. In actual fact the maximum segment length is 185 meters. Thin coaxial cable has been popular in • Thick coaxial cable is also referred to as thicknet. 10Base5 refers to the specifications for thick coaxial cable carrying Ethernet signals. The 5 refers to the maximum segment length being 500 meters. Thick coaxial cable has an extra protective plastic cover that helps keep moisture away from the center conductor. This makes thick coaxial a great choice when running longer lengths in a linear bus network. One disadvantage of thick coaxial is that it does