ICT II Unit 6 Networking

What is a network? A network is a group of computers connected together in such a way as to allow resources to be shared.

What is a network consisted of? A network is consisted of two or more computers that are linked in order to share resources (such as printers and CD-ROMs), exchanges files, or allow electronic communication.

How are networks connected? Through cables Through telephone lines Through radio waves Through satellites Through infrared light beam

Types of Network LAN MAN WAN

LAN LAN – Local Area Network Confined relatively to a small area Generally limited to a building or a geographical area Expanding no more than a mile apart to other computers

Components of LAN A file server – stores all of the software that controls the network, as well as the software that can be shared but the computers attached to the network A workstation – computers connected to the file server (Mac or PCs); less powerful than the file server Cables – used to connect the network interface cards in each computer

LAN

MAN Metropolitan Area Network Covers larger geographical areas, such as cities Often used by libraries and government agencies to connect to citizens and private business industries

MAN

WAN Wide Area Network Connect larger geographical areas, such as London, the UK, or the world

WAN

Advantages of Networking Speed – Sharing and transferring files within networks are very rapid, thus saving time, while maintaining the integrity of the file. Cost – Individually licensed copies of many popular software programs can be costly. Networkable versions are available at considerable savings. Shared programs can easily be upgraded on the server rather than on individual workstations. Security – Sensitive files and programs on a network are passwords protected against illegal copies.

Advantages of Networking Centralized Software Management – Software can be loaded on one computer (the file server) eliminating the need for the software to be added on independent computers throughout the building. Resource Sharing – Sharing of printers, fax machines, and modems Flexible Access – Files can be accessed from computers throughout the firm.

Advantages of Networking Electronic Mail – E-mail aids in personal and professional communication. E-mail will enable staff and students to communicate within the building and or classroom without having to leave their desks. Workgroup Computing – Workgroup software allows many users to work on a document or project concurrently.

Advantages of Networking Peripherals such as printers can be shared amongst many different users. Terminals are cheaper than stand-alone PCs. Software can be shared amongst different users. Communication across the network is cheap and fast.

Disadvantages of Networking Servers’ faults stop application from being available. Network faults can cause loss of data. Network faults can lead to loss of resources. User work is dependent upon network. System is open to hackers. Decisions tend to become centralized. They could become inefficient. They could degrade in performance. Resources could be located too far from users. Network management can become different.

Disadvantages of Networking Cabling can be expensive to install and replace. A fault with the server will prevent the whole network from working. Security measures are needed to restrict access to the network. WANs are vulnerable to hackers and viruses.

Advantages/Disadvantages of Networking Some Advantages Some Disadvantages A user can logon to a computer anywhere on the network and access work files from the file server. If something goes wrong with the file server, the whole network is unable to operate. Computers can be managed centrally with the same software installed on each one. The technical skills needed to manage a network are much higher than working on a stand-alone computer. Time- It is much faster to install an application once on a network and copy it across the network to every workstation. It would take a long time to install software applications on each computer one at a time. Sharing printers, plotters, modems, and so forth saves money and time. It can be frustrating to print to a printer in another room and then find after a long trek that there is no paper in the printer. Security- The Network Manager can allocate usernames and passwords to all users to try to prevent unauthorized access. Users may use up too much of the storage space, and this may cause problems on the network. It is easy and convenient to monitor users. For example, Web sites visited or documents printed can be monitored using software running on the server. Users may use too much bandwidth, for example, when listening to music files or watching video clips - preventing others from using the network facilities properly.

Components of a Network Hubs -simply connects all of the devices on its ports together Switches hubs - A switch is like a tiny telephone company that lets pairs of devices make direct connections. Cables Network adapters cards

Components of a Network Router - a device that transfers data from one network to another in an intelligent way Server - computer or device on a network that manages network resource