Transcript of Networks
4 basic elements of an ICT network Transfer of data in ICT System 1. Communication devices Data Transfer Media Network standards and procedures 2. Networking Software Network Operating System Fiber Optic cable Network interface Cards A hub A Switch A router Network Management Software Wifi LANs & WANs Local Area Network Wide Area Network a network that is spread over a wide geographical area a network the links devices in a building e.g. home/office What is a Network? A network is where to or more computers are linked together whereby they have the ability to exchange files, share hardware resources, allow electronic communication etc. Disadvantages of a Network Advanced technical knowledge required; specialist staff needed to setup and run a network If the file server fails, all computers connected to the network will not operate and users will not be able to access files Setting up a network is expensive; high cost of equipment and training Advantages of a Network Ability to share files Ability to share hardware resources Ability to share software Easier to backup files Ability to work in files simultaneously a cable containing one or more optical fibers (flexible, transparent fiber made of glass or plastic, slightly thicker than human hair) Technology that allows electronic to exchange data wirelessly over a computer network including high-speed internet Advantages & Disadvantages of Wifi allows inexpensive LANs to be setup without cables You can use Wifi WW There are health problems surrounding Wifi Power Consumption is high Home networks have limited range Advantages & Disadvantages of Fiber Optic Extremely high-speed internet Resistance to electromagnetic interference Early detection of cable damage Very expensive to setup Susceptible to physical damage Special test equipment is often required Huge group of networks joined together InTERnet Allows e-mail Allows instant messaging FTP: file transfer protocol- a way of exchanging files via the internet P2P; peer-to-peer- enables mp3 file sharing with other users which is ILLEGAL InTRAnet The Intranet is a private network Mainly use to share organizational information and resources ExTRAnet The intranet is restricted to employees of a particular organization; with the extranet, customers, suppliers and other partners can access information. However they are not accessible to the general public. The WorldWideWeb A.K.A WWW is a means of accessing information from the internet An example where you will see this isFull transcript
http://www.apple.com/uk http? WWW is a information sharing model that is built ontop of the internet, WWW uses http to access webpages. Network Topology Network topology describes a networks layout and the way in which the computer and hardware, known as nodes, are all linked together. Bus Topology In Bus topology all nodes of the network are connected to the central line and all data transmitted goes through the central cable Ring Topology In Ring topology all nodes are connected together in a loop, data is transmitted from node to node in a single direction Star Topology In Star Topology all nodes are directly connected to the central computer or mainframe More secure connection as data is sent directly between nodes
A failure of the cable will only affect one node, hence faults are easier to pinpoint.
Easy to add new nodes without any disruption Requires and is dependent upon a central computer.
Requires more cable and is therefore more expensive to setup. Advantages Disadvantages Data transmission is fast and simple because data can only travel in one direction
There is no dependence or need of a central computer or mainframe. If one node fails then data cannot continue to be transferred and therefore all other nodes fail
Harder to add new nodes into the system, requires the network to be disrupted. Advantages Disadvantages Easy to add and remove nodes
Requires small amount of cable; quite cheap and easy to setup and troubleshoot. A failure in the central line means the whole network will go down.
Data can on travel in one route therefore performance will lack because more data is transmitted Advantages Disadvantages