Fundamentals of Networking

Question 1

What is a computer network?

Answer 1

Two or more computers connected together, in order to share resources/ data.

Question 2

What are the advantages of using a network?

Answer 2

Users can share files
Users can share peripherals (e.g. printers and connections to other networks e.g. the internet)
Users can access their files from any computer on the network
Servers can control security, software updates and backup of data
Communication with other people

Question 3

What are the disadvantages of using a network?

Answer 3

Increased security risk to data
Malware and viruses can spread easily between computers
If a server fails, the connected nodes may not work either
The computer may run slower if there is lots of data travelling on the network

Question 4

What is PAN?

Answer 4

Personal Area Network - A network of personal devices, which can be linked using Bluetooth. It is owned by a single person

Question 5

What is LAN?

Answer 5

Local Area Network - A network spanning over a small geographical area. Usually owned by a single person or organisation.
They are wired with UTP cable, optic fibres or wireless with Wi-Fi

Question 6

What is WAN?

Answer 6

Wide Area Network - A network spanning over a large geographical area. Usually under collective or distributed ownership. Biggest example is the internet.
They are connected with telephone lines, optic cables or satellite links.

Question 7

What are the advantages of wired networks?

Answer 7

Faster than wireless networks
Add more pls

Question 8

What are the disadvantages of wired networks?

Answer 8

Not portable.
Inconvenient to have lots of cables running through the home.

Question 9

What are the advantages of wireless networks?

Answer 9

Portable connection
Running lots of cables through a home is impractical

Question 10

What are the disadvantages of wireless networks?

Answer 10

Radio signals may be disrupted due to interference

Question 11

What are the two types of LAN topologies?

Answer 11

Bus and Star

Question 12

Describe the setup of bus topology

Answer 12

All computers and peripherals are connected to a single bus. Computers can send messages and data across the bus, which are the received by other devices connected to the network

Question 13

Describe the setup of star topology

Answer 13

All devices are connected to a central hub. Messages/ data are passed through the hub and the delivered to the intended recipient.

Question 14

What are the advantages and disadvantages of using bus topology?

Answer 14

Adv: Easy to extend a bus
Reliable and easy to understand

Dis: If the central bus breaks the entire network fails and all computers lose connection.
Only one computer can send a message through the backbone at a time, meaning the speed of the network can be affected by the number of computers attached.

Question 15

What are the advantages and disadvantages of using star topology?

Answer 15

Adv: If one cable breaks it doesn’t affect the entire network.
It’s easy to add new computers to the network without disrupting the others.
Fastest type of network - each computer has its own dedicated supply line, so avoids ‘data clashes’

Dis: If the hub stops working, the entire network stops working.
More expensive - more cabling.

Question 16

Why is network security important?

Answer 16

To prevent unauthorised users from entering the network

Question 17

What are some types of network security?

Answer 17

Authentication
Encryption
Firewall
MAC Address Filtering

Question 18

Explain how authentication works

Answer 18

A user will enter a username or password (or equivalent) into a system to determine whether they are allowed entry. The system will match the entered details to ones already stored on the system, and if they match, it means the user is who they are intended to be and be allowed entry.

Question 19

Explain how encryption works

Answer 19

Encryption is the process of turning plaintext into an unreadable form. It doesn’t prevent hacking, but makes the code unreadable to unauthorised users. Only users with an encryption key can translate the cyphertext back into its original form.

Question 20

Explain how firewall works

Answer 20

A firewall is software or hardware that has been configured to only let specific types of traffic into and out of networks. The network manager is able to open or close ports depending on the type of traffic they want to use for the network.

Question 21

Explain how MAC address filtering works

Answer 21

MAC address is unique per device, therefore the network manager can create a more secure network by using the address to limit the devices on the network. They can do this by having either:
Whitelist - only devices on this list can access the network, more secure but is extra work for the network manager.
Blacklist - devices on this list are banned from the network, less secure but easier to maintain.

Question 22

What is a network protocol?

Answer 22

A set of rules that devices must follow to communicate.

Question 23

What is the TCP/IP model?

Answer 23

A framework for organising the set of communication protocols used in networks.

Question 24

What are the layers of the TCP/IP model and what are their functions?

Answer 24

Application Layer - where applications (such as web browsers and email programs) operate.
Transport Layer - breaks down the message into small segments called packets. Each packet is given a packet number, and total number of packets.
Internet Layer - adds the sender’s and recipient’s IP address to the packet. It packages data to make it ready for transmission and routes the packets across the network.
Link Layer - the hardware and os drivers are on this layer.

Question 25

Which protocols operate on the application layer and what are their functions?

Answer 25

HTTP - governs communication between webserver and client, a way for the client and server to receive requests and deliver HTML web pages.
HTTPS - a more secure version of HTTP, includes encryption to allow provide security over sensitive information.
FTP - governs the transmission of files across a network and the internet
IMTP - governs receiving emails from email severs
SMTP - governs sending emails over a network to a mail server.

Question 26

Which protocols operate on the transport layer and what are their functions?

Answer 26

UDP - similar to TCP, but messages are sent, instead of packets. It’s sometimes faster and good for video calls.
TCP - provides error free transmission between two routers

Question 27

Which protocol operates on the internet layer and what is its function?

Answer 27

IP - routes packets across a wide area network. Gives each device a unique IP address.

Question 28

What is Wi-Fi?

Answer 28

A set protocols used for wireless communication

Question 29

What is Ethernet?

Answer 29

A standard set of protocols used in LANs