Networks and Topologies Networking systems Networks and Topologies

Outcomes 5.2.1 – Describes and applies problem-solving processes when creating solutions 5.2.2 designs, produces and evaluates appropriate solutions to a range of challenging problems 5.2.3 critically analyses decision-making processes in a range of information and software

Link to Core Topic 1 – Design, Produce and Evaluate Producing the Solution Develop and implement the stages involved in the completion of a solution Apply set criteria to choose the most appropriate solution

Networks What is a Network? The interconnection of computers, terminals, or other devices that form a path over which the devices communicate and share hardware, software and other resources The Internet is arguably the worlds largest communication network (Shelly, Chasman, & Serwatka, 2004)

Components of a network Server Router Hub Computer

The server A server is a specialised computer which stores and controls access to data. It processes the requests of a client computer and delivers data to the client from the internet. Types of servers File servers: store files and data used and shared by computers in a network. Print servers: process the printing requests of a client in a network. Mail server: process and store emails as well as manage email accounts.

The router A router allows data to be transmitted to a computer. The data is received in packets. The packets have destination addresses attached to them which are shown in a set of four integers which are separated by full stops. Only data with the correct destination address will be accepted by the router to be transmitted to the computer. Picture: http://www.cguy.net/wireless_networking_guide/configuring_the_wireless_router.php

The hub A hub is a device which is central to the network which connects the devices to one another, essentially creating a network. All devices are connected to the hub on a network. Picture: http://www.hw-group.com/products/poseidon/pos_s-hub_en.html

The computer The computer responds and executes specific commands by the network as well as by the person using the computer. Types of computers: Personal computer: (PC) microcomputers. Can be a client or a stand alone processor. Workstation: General purpose computer, more powerful than a personal computer. Supercomputer: performs tasks at the highest speed. Most powerful computer.

Types of Networks LAN – Local Area Network WAN – Wide Area Network VPN – Virtual Private Network

LAN - Local Area Network A Local Area Network is used to connect computers and other types of devices in a small geographical location Examples Home School Office Building Cable Modem Router /Switch

LAN – Local Area Network Design Ethernet cable – an effective way to serve as a data transfer medium for internet protocols and can be as long as they are needed. Wireless – USB in the computer or laptop which allows data to be transmitted – most laptops contains inbuilt wireless signals Application Data sharing – allows data storage in any central computer where it can then be shared throughout the organisation File transfer and recovery is easy because it is backed up on a single server Saves money on the installation of various softwares because they can be shared centrally Hardware such as printers and scanners can be used equally from one unit

LAN – Local Area Network Internet Computer 1 Computer 2 Computer 3 Modem/Server Ethernet Cables

LAN Topologies Star Ring Bus

LAN Topologies Star a central device to which all the other devices in the network are connected to. Data passes directly from the central hub to the destination terminal Changes can be made easily because only one client is on each line If the hub fails, the entire network is down Hub

LAN Topologies Ring Each workstation is connected to the workstation before it and the workstation after it, forming a logical ring

LAN Topologies Bus Each workstation is connected to a single wire. The ends of the wire have a terminator, which tells the network to end. A bus runs the entire length of the cable and the ends are not attached to each other.

Class Activity Demonstrate a LAN.

WAN – Wide Area Network A Wide Area Network is used to connect computers which are hundreds or thousands of kilometres apart through the use of the telephone network. Example: Company Offices in different cities Employees in different states International Offices

WAN – Wide Area Network Are a collection of LANs connected together across a state, country or the world linked to one main computer through a private leased line, the public telephone network or a combination of both They were originally developed to only transmit voice rather than data The private leased line is dedicated to the network and offers a higher transmission speed as well as more accurate and secure transfer of data. Can be expensive Cost increase if the distance between locations increase Transmit data at a slower rate than LAN The most basic uses of WANs are for electronic mail and file transfer

WAN Topologies HIERARCHICAL STAR RING

WAN Topologies Hierarchical The server is at the top of the hierarchy, followed by a front end processor which processes information. From there, information is sent to the controller which connects the clients. Clients are therefore the last in the hierarchy.

WAN Topologies Hierarchy SYDNEY ADELAIDE

WAN Topologies Star A central server with devices connected point to point. The server polls a client before data can be sent. There is no device used to process data transmission, causing the server to take on a larger processing burden.

WAN Topologies Star

WAN Topologies Ring Servers are connected in a ring formation. Although each network in itself may be connected in a hierarchical formation, the servers themselves are connected in the ring formation for ordered processing and data transfer.

WAN Topologies Ring

Class activity Demonstrate a WAN.

VPN- Virtual Private Network A Virtual Private Network uses the public telephone network and the Internet to carry encrypted data Example Educational Facilities Home Business

VPN- Virtual Private Network First development was the Intranet, a password protected site for company employees only. Virtual Private Networks are created by businesses or educational institutes which allow employees and students to access their LANs using a password so they can work or study from home. Instead of a leased line like WANs, VPNs use a virtual connection routed through the internet to other employees Designed to assist employees in working together

VPN Networks Social networking in Plain English. http://www.youtube.com/watch?v=6a_KF7TYKVc

References Commoncraft. (2007, June). Social Networking in Plain English. Gliffy Incorporated. (2010). Retrieved April 2011, from Gliffy: http://www.gliffy.com/ Shelly, G. B., Cashman, T. J., & Serwatka, J. A. (2004). Business Data Communications. Massachusetts: Thomson.

Class activity Gliffy http://www.gliffy.com/ Gliffy is an online application which allows you to create, share and collaborate with diagrams. No need to install. Able to be used anywhere on the go. Nothing saved to the hard drive, everything is stored online. It is used to create, but not limited to: Flow charts Website maps Floor plans Venn diagrams Technical drawings