NETWORKING SYSTEMSNetworks 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.

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.

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

SchoolOffice Buildin

g

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

Internet

Computer 1 Computer 2 Computer 3

Modem/Server

Ethernet Cables

LAN – Local Area Network

LAN Topologies

Star

Ring

Bus

Star a central device to which all the other devices

in the network are connected to.

LAN Topologies

Hub •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

Ring Each workstation is connected to the

workstation before it and the workstation after it, forming a logical ring

LAN Topologies

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

statesInternational 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