08-16-2017, 10:22 PM
computer networks by bakshi pdf free download
A computer network is a set of computers connected together for the purpose of sharing resources. The most common resource shared today is connection to the Internet. Other shared resources can include a printer or a file server. The Internet itself can be considered as a computer network.
Computer Network Defined
A computer network is a set of connected computers. Computers on a network are called nodes. The connection between computers can be done via cabling, most commonly the Ethernet cable, or wirelessly through radio waves. Connected computers can share resources, like access to the Internet, printers, file servers, and others. A network is a multipurpose connection, which allows a single computer to do more.
Types of Network Connections
Computer networks can be broken down historically into topologies, which is a technique of connecting computers. The most common topology today is a collapsed ring. This is due to the success of a network protocol called the Ethernet. This protocol, or a network language, supports the Internet, Local Area Networks, and Wide Area Networks.
Star Topology
A star topology is a design of a network where a central node extends a cable to each computer on the network. On a star network, computers are connected independently to the center of the network. If a cable is broken, the other computers can operate without problems. A star topology requires a lot of cabling.
Bus Topology
A bus topology is another type of design where a single cable connects all computers and the information intended for the last node on the network must run through each connected computer. If a cable is broken, all computers connected down the line cannot reach the network. The benefit of a bus topology is a minimal use of cabling.
Collapsed Ring Topology
A similar topology is called a ring. In this design, computers are connected via a single cable, but the end nodes also are connected to each other. In this design, the signal circulates through the network until it finds the intended recipient. If a network node is not configured properly, or it is down temporarily for another reason, the signal will make a number of attempts to find its destination.
A collapsed ring is a topology where the central node is a network device called a hub, a router, or a switch. This device runs a ring topology internally and features plugins for cables. Next, each computer has an independent cable, which plugs into the device. Most modern offices have a cabling closet, or a space containing a switch device that connects the network. All computers in the office connect to the cabling closet and the switch. Even if a network plug is near a desk, the plug is connected via a cable to the cabling closet.