Computer Networks

Types of Network

Computer Science Tutor

https://www.youtube.com/watch?v=TdQgP_Gee_A&list=PL04uZ7242_M6O_6ITD6ncf7EonVHyBeCm&index=29

Local Area Network

Local Area Networks (Also known as "LAN") is a form of networking that allows devices to communitcate to eachother and networks, LAN is connected via an Ethernet cable then connected to a server or a router to connect to a network or another device. LAN is connected by Ethernet Cables, these are made up of coxial cable in different types. This, for a long time, was the only way to connect a computer as they used to have where they would connect to a mainframe and then a computer would be connected by Ethernet cable to the mainframe, making it a Local Area Network.

Wide Area Network

A Wide Area Network, or WAN, is made up of several computer networks connected together, often over the Internet. In most cases, the networks in WANs all belong to the same company or school. WANs are used to connect LANs and other types of networks together, so that users and computers in one location can communicate with users and computers in other locations. Many WANs are built for one particular organization and are private. Others, built by Internet service providers, provide connections from an organization's LAN to the Internet.

The following image demonstrates how a wide area network is used in a computer network:

Why do we network devices

Benefits of Networking

• Sharing devices like printers saves money.
• Site licences are likely to be cheaper than buying several standalone licences.
• Files can easily be shared between users.
• Network users can communicate by email.
• Security is good, users cannot see other users' files unlike on stand-alone machines.
• Data is easy to backup as all the data is stored on the file server.
• Single password per user instead of per device.

Drawbacks of Networking

• Purchasing the network cabling and file servers can be expensive.
• Managing a large network is complicated, requires training and a network manager usually needs to be employed.
• If the file server breaks down the files on the file server become inaccessible.
• Viruses can spread to other computers throughout a computer network.
• There is a danger of hacking, particularly with WANs.
• If there's a break in the network is down no work on computers can take place.

Revision Questions

Question 1

1. what does CSMA/CD (carrier sense multiple access with collision detection) do when a collision is detected?

	stops sending data from all included devices and produces an error message
→	doesn't just just sending
	stops sending data all devices wait a random ammount of time then retry
→	correct
	keeps retrying until sent
→	incorrect this would not work and will stop the computer
	data is transfered through the air instead
→	this cannot be done with this protocol or possible in these systems

Your score is 0 / 0

Question 2

1. Select all the benefits of networking:

	All devices such as printers are independent to a machine which saves money
→	Incorrect
	Files can easily be shared between users
→	Correct
	Data is easy to backup as all the data is stored on the file server
→	Correct
	It's easier to travel
→	Leave your fridge open to stop global warming.
	Site licences are likely to be cheaper than buying several standalone licences
→	Correct

Your score is 0 / 0

Question 3

1. Which of the following apply to a LAN? (Multiple Answers)

	It is a form of networking that allows devices to communicate with each other and networks
→	This is correct.
	It is connected via fibre optic
→	This is incorrect; it is connected via Ethernet
	It is connected via coaxial cables in the form of Ethernet
→	This is correct.
	It was the only way to connect a computer for a long time.
→	This is correct; they used to connect a mainframe to a computer via ethernet
	It is a geographically remote network
→	This is incorrect; it is geographically confined.

Your score is 0 / 0

Question 4

1. Define a Peer-peer network:

	Devices connected to a server to communicate with each other
→	Incorrect
	Devices with equal status, with no servers connected
→	Correct
	Devices connected to a WAN
→	Incorrect

Your score is 0 / 0

Question 5

1. Which of these are advantages of star topologies compared to bus topologies?

	They are more expensive
→	This would be a disadvantage
	Multiple devices can send and receive data at the same time
→	Correct
	Requires more cable than bus topologies
→	This is a disadvantage
	If one cable fails the network still works
→	Correct

Your score is 0 / 0

Question 6

1. What does LAN stand for?

	Logical active network.
→	Local area network was the correct answer.
	Nothing
→	Bruh.
	Local area network.
→	Noice one.
	Live area network.
→	Local area network was the correct answer.

Your score is 0 / 0

Question 7

1. What does WAN stand for?

	Wired Access Network
→	Incorrect, it stands for Wide Area Network
	Wide Area Network
→	Correct
	Wireless Anatomy Network
→	Incorrect, it stands for Wide Area Network
	Wayne's Army Network
→	NO! It stands for Wide Area Network

Your score is 0 / 0

Question 8

1. What are the communications media used in a WAN

	Ethernet
→	Ethernet cables connect devices in a WAN together.
	USB.
→	USB is not used in a WAN.
	Router.
→	Routers allow networks to connect to a LAN.
	Hub.
→	Hubs send data to all connected devices.
	Switch
→	Switches send data to the device that requested it, or to the device it is directed to.
	Coaxial cable
→	Coaxial cable is not used within a WAN.

Your score is 0 / 0

Question 9

1. Which of these is not a drawback of using LAN?

	Saves money by sharing devices, like printers
→	This is a benefit
	Managing a LAN is complicated
	Easy to back up data
→	This is a benefit
	Viruses can spread to other computers throughout the network

Your score is 0 / 0

Question 10

1. State the advantages of a star topology over the bus topology.

	Less chance of data collisions
→	Correct
	Easier to detect faults
→	Correct
	Less cable overall is needed
→	Incorrect
	Easier to connect a computer or peripheral compared to a bus topology
→	Incorrect
	No disruptions to the network when removing and connecting devices
→	Correct

Your score is 0 / 0

Question 11

1. Which of these is an benefit of networking?

	Files can easily be shared between users.
→	Correct answer
	Purchasing the network cabling and file servers can be expensive.
→	The correct answer is "Files can easily be shared between users."
	Managing a large network is complicated, requires training and a network manager usually needs to be employed.
→	The correct answer is "Files can easily be shared between users."
	Viruses can spread to other computers throughout a computer network.
→	The correct answer is "Files can easily be shared between users."

Your score is 0 / 0

Question 12

1. Define the term protocol:

	A device that a network can connect to
→	Incorrect
	A set of rules that computers use to communicate with each other
→	Correct
	A network topology layout
→	Incorrect
	The type of communication method used when computers connect
→	Incorrect

Your score is 0 / 0