NETWORKS PROFESSIONAL ENGLISH IN USE FOR COMPUTER

 

PROFESSIONAL ENGLISH IN USE FOR COMPUTER 20.NETWORKS

 

A LANs (Local Area Networks) Networking allows two or more computer systems to exchange information and share resources and peripherals. LANs are usually placed in the same building. They can be built with two main types or architecture: peer-to-peer, where the two computers have the same capabilities, or client-server, where one computer acts as the server containing the main hard disk and controlling the other workstations or nodes, all the devices linked in the network (e.g. printers, computers, etc.) Computers in a LAN need to use the same protocol, or standard of communication. Ethernet is one of the most common protocols for LANs. B Network topology Topology refers to the shape of network. There are three basic physical topologies. ·       Star: there is a central device to which all the workstations are directly connected. This central position can be occupied by a server, or a hub, a connection point of the elements of network that redistributes the data. ·       Bus: every workstation is connected to a main cable called a bus. ·       Ring: the workstations are connected to one another in a closed loop configuration. There are also mixed topologies like the tree, s group of stars connected to a central bus. C WANs (Wide Area Networks) WANs have no geographical limit and may connect computers or LANs on opposite sides of the world. They are usually linked through telephone lines, fibre-optic cables or satellites. The main transmission paths within a WAN are high-speed lines called backbones. Wireless WANs use mobile telephone networks. The largest WAN in existence is the Internet. EXERCISES 20.1 Read the information opposite and correct the following statements. 1 LANs link computers and other devices that are placed far apart. 2 In a client-server architecture, all the workstations have the same capabilities. 3 The word protocol refers to the shape of the network 20.2 Use the words in the box to complete the sentences. LAN nodes hub backbones WLAN peer-to-peer server     1 All the PCs on a ________ are connected to one ________, which is a powerful PC with a large hard disk that can be shared by everyone. 2 The style of ________ networking permits each user to share resources such as printers. 3 The star is a topology for a computer network in which one computer occupies the central part and the remaining ________ are linked solely to it. 20.3 Read these descriptions of different physical topologies of communication networks and match them with terms in B opposite. 1 All the devices are connected to a central station. 2 In this type of network there is a cable to which all the computers and peripherals are connected. 20.4 A network administrator has set up a new network in a school. Which topology has she chosen?

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