Networks

Unit 3 & 4 IP&M

JEOPARDY

Acknowledgements:• VITTA for the jeopardy pro-forma• Mark Kelly’s Network slideshow

Reasons For Reasons For NetworksNetworks

NetworkNetworkHardwareHardware

Network Network TypesTypes

Lucky Lucky DipDip

NetworkNetworkTopologies Topologies

100 100 100 100 100

200 200 200 200 200

300 300 300 300 300

400 400 400 400 400

500 500 500 500 500

Reasons For Networks100

At its simplest, a network is two or more computers that are connected so they can exchange information and share resources.

A: What is a network?

Reasons For Networks200

A: How does a network improve communications?

Email, videoconferencing and chat are examples of how a network improves this.

Reasons For Networks300

A: Why network?

a They allow you to share information, save money on expensive equipment and communicate better with customers and employees.

Reasons For Networks 400

A: What are the efficiency indicators of a network?

Faster communication, cost savings (compare email costs with phone calls and physical travel)

Reasons For Networks 500

A: How does a network make an organisation more effective?

Collaborative work is easier, access to resources broader.

Network Hardware100

A: What is a NIC (network interface card)?

This allows a stand-alone computer to connect to a network. There are cabled and wireless cards.

Network Hardware200

A: What is a server?

This is a robust central computer at the heart of the network

Network Hardware300

A: What is a switch?

These are connection points where cables can join up a split. Typically, a

single incoming cable is split into multiple outgoing cables.

Network Hardware400

A: What is a router?

These are security devices that guard the connection between a LAN and the outside world (another LAN or WAN). They can be programmed to allow only authorised incoming and outgoing traffic as well as block one part of the network from another part.

Network Hardware500

A: What is a repeater?

These boost fading network signals on long cables.

Network Types100

A: What is a LAN?

It is typically restricted to one building or one site. Can be cabled - UTP, coaxial or wireless. Longer distance between buildings may need fibre optic cable.

Network Types 200

A: What is a WAN?

It is spread over wide distances. Connections use landline data cables (eg ISDN, ADSL), satellite.

Network Types 300

A: What is a MAN?

It is usually within a limited geographical region eg. A city. Connections usually with landline data cables (ISDN, ADSL), microwave, fibre optic cable.

Network Types 400

A:What is the Internet?

This is made up of inter-networked WANS. May run on UTP, coaxial, fibre optic, satellite, microwave, wireless, mobile phones, modems over phone lines. High speed digital data lines, submarine cables and even mains power lines.

Network Types 500

A: What is TCP/IP?

(transfer communication protocol/ internet protocol)

The universal protocol for Internet use - the backbone of the Internet.

Lucky Dip100

A: What does a star topology look like?

Lucky Dip200

A: What is fibre optic cable?

This is made of glass and is optical not electrical meaning little signal fade. Can transmit multiple signals on a single fibre. It is very fast, flexible, has high bandwidth, can travel long distance without repeaters and is very secure.

Lucky Dip300

A: What is a token ring network?

This allows only one node to transmit at one time. A node can only transmit if it holds a special network packet called a token.

Lucky Dip400

A: What is Ethernet?

This defines both how packets are handled and cabling options. When a node wants to communicate to another node, it transmits its addressed packet. The packet travels to every node on the segment. Each node inspects the packet however only accepts it if it is addressed to them.

Lucky Dip500

A: What are two problems for the average network user?

Two examples of this are:• Quality of the connection needs to be higher where there are many users as more people connected can slow down transmission. (think of our Internet connection• Users sometimes have to wait for resources (eg. Print queues)

Network Topologies 100

A: What is a ring topology.?

In this type of topology every device has exactly two neighbours for communication purposes. All messages travel in the same direction. A failure in any cable or device will take down the entire segment. They are more expensive and slower.

Network Topologies 200

A: What is a star topology?

This topology has a central connection point- usually a hub or switch with cables branching to many nodes. While it takes more cable, the benefit is that is a cable fails; only one node will be brought down.

Network Topologies 300

A. Why is a tree topology?

Also known as the ‘hierarchical topology’, this topology is a combination of bus and star topologies and is very common in larger networks. The node in the highest point in the hierarchy – usually the server – controls the network.

Network Topologies400

A: What is mesh topology?

This topology uses lots of cables to connect every node with every other node. It is very expensive to wire up but if one cable fails there are alternative ways to communicate.

Network Topologies500

A: What is a bus topology?

Many devices connect to a single cable ‘backbone’. If the backbone is broken the entire segment fails. They are relatively easy to install and don’t require much cabling compared to the alternatives, however they get congested with too many nodes. They are best for small networks.