1. Networks and Topologies
Networking systems
Networks and Topologies

2. 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

3. 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

4. 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)

5. Components of a network
Server
Router
Hub
Computer

6. 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 s
as well as manage accounts.

7. 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:

8. 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:

9. 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.

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

11. 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

12. 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

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

14. LAN Topologies
Star
Ring
Bus

15. 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

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

17. 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.

18. Class Activity
Demonstrate a LAN.

19. 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

20. 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

21. WAN Topologies
HIERARCHICAL
STAR
RING

22. 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.

23. WAN Topologies
Hierarchy
SYDNEY
ADELAIDE

24. 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.

25. WAN Topologies
Star

26. 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.

27. WAN Topologies
Ring

28. Class activity
Demonstrate a WAN.

29. 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

30. 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

31. VPN Networks Social networking in Plain English.

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

33. 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