Fundamentals of Computer Networks

Question 1

Computer Network

Answer 1

A collection of computers linked together to facilitate communication and the sharing of resources. They can be connected through wired, or wirelessly.

Question 2

Advantages of computer networking:

Answer 2

• Allows you to share files with other computers/users
• Roaming access - a user can log onto another device on the same network and be able to access the same files
• Sharing hardware components (eg. printers)
• Centralised updates for larger networks
• Users can communicate

Question 3

Disadvantages of computer networking:

Answer 3

• Increased risk of hacking
• Viruses can spread more easily
• Hardware necessary for networking can be expensive
• Larger networks require more management
• Reliance upon networked resources

Question 4

The three main types of computer network:

Answer 4

• Local Area Network (LAN)
• Wide Area Network (WAN)
• Personal Area Network (PAN)

Question 5

Local Area Network

Answer 5

A network of computers that cover a smaller area, such as a school or college. A LAN is geographically confined to one location.

Question 6

Personal Area Network (PAN)

Answer 6

A PAN is a network that covers a very small area, often covering only a few metres. PANs are often used to connect personal devices like mobile phones, laptops, or headphones.

Question 7

Wide Area Network (WAN)

Answer 7

A network that spans over a larger area. A WAN can be spread over multiple different sites, or even countries.

Question 8

Network Interface Cards (NICs)

Answer 8

Offers an interface port for wired connection. However, there are models that can offer a radio transceiver for wireless connection instead.

Question 9

Wireless Access Point (WAP)

Answer 9

Allows wireless connections to a network using a radio transceiver. They can also be used to expand an existing computer network and can be connected to the main network through a cable.

Question 10

Switch

Answer 10

Records which computers are connected to which ports. When traffic is received, they divert the information the the intended recipient only, which improved network performance.

Question 11

Router

Answer 11

Used to send signals across the internet. They collect knowledge of all the available roots for data transmission, and choose the most suitable route for the circumstances.

Question 12

Packet Switching

Answer 12

The transfer of small pieces of data across various networks.

Question 13

Wi-Fi

Answer 13

A family of protocols that make networking run smoothly.

Question 14

How do wireless networks carry signals?

Answer 14

Through the use of radio waves

Question 15

How do wired networks carry signals?

Answer 15

Through use of cabling/wires

Question 16

Maximum transmission speed of a wired network

Answer 16

Up to 1 gigabit per second

Question 17

Maximum transmission speed for a wireless network

Answer 17

Up to 50 megabits per second

Question 18

What are the two types of networks?

Answer 18

Wired and wireless

Question 19

Which type of network is the most secure and why?

Answer 19

Wired networks, as they have a physical connection

Question 20

Which type of network is cheaper to set up?

Answer 20

Wireless networks, as devices can connect as long as they’re in the range of a WAP, so there’s no need for physical connection/cabling.

Question 21

Which type of network is easier to install?

Answer 21

A wireless network, as most devices connect automatically.

Question 22

IP (Internet Protocol) Address

Answer 22

A unique address given to each device that can outwardly connect to the internet.

Question 23

Network Topology

Answer 23

The physical and logical arrangement of nodes and connections in a computer network.

Question 24

What are the three most common LAN topologies?

Answer 24

• Bus
• Star
• Ring

Question 25

Bus topology

Answer 25

Each computer is connected to a single table

Question 26

Ring Topology

Answer 26

Computers are connected in a loop, with data being sent around the ring until it reaches the correct computer

Question 27

Star Topology

Answer 27

Ever6 computer has their own cable connecting them to the central switch

Question 28

What are the advantages of a Bus network?

Answer 28

- No reliance on a central device or ‘node’ - It’s easy and inexpensive to install because there’s less cabling involved

Question 29

What are the advantages of a star network?

Answer 29

- If one cable fails, the others aren’t affected - Consistent performance - Good security as data is only received/sent to the computer that requires it

Question 30

What are the disadvantages of a bus network?

Answer 30

- If the main cable goes down, the whole network does too - Hard to isolate cable failures as all computers in the network are affected - Performance decreases as traffic increases - Low security as all the computers see all the transmissions

Question 31

What are the disadvantages of a star network?

Answer 31

- Can be expensive to install as it requires lots of cabling - If the server/central switch fails, then the whole network goes down

Question 32

Authentication

Answer 32

Identifying a genuine, authorised user. An example of this is when a device asks for a username and password to be unlocked.

Question 33

When would you use authentication?

Answer 33

In a networked environment where computers are used by more than one user, such as a school.

Question 34

Encryption

Answer 34

Protecting data from being hacked and accesses illegally.

Question 35

When would you use encryption?

Answer 35

- To protect data that’s being transmitted over the internet, like bank details.

Question 36

Firewall

Answer 36

Monitors network traffic and decides whether to allow or block certain traffic based on security rules. For example, certain IP Addresses may be blocked.

Question 37

Why would you use a firewall?

Answer 37

To protect a whole network from external threats

Question 38

MAC address filtering

Answer 38

Determines which devices are allowed on a network based on each device’s individual MAC address.

Question 39

When would you use MAC address filtering?

Answer 39

To protect a network from external threats.

Question 40

What’s the downside to MAC address filtering?

Answer 40

It can only monitor devices, not their users.

Question 41

Why are networks more vulnerable to hackers than standalone devices?

Answer 41

Once the hacker gets access to one device, they can access the whole network.

Question 42

Network Protocol

Answer 42

A set of rules that define how devices within a network communicate with each other.

Question 43

What are the two main email protocols?

Answer 43

- SMTP (Simple mail transfer protocol) - IMAP (Internet message access protocol)

Question 44

Plaintext

Answer 44

The original message that’s being encrypted

Question 45

Ciphertext

Answer 45

The encrypted message

Question 46

Decryption

Answer 46

The process of converting ciphertext into plaintext

Question 47

Key

Answer 47

A sequence of number used to encrypt or decrypt, often using a mathematical formula

Question 48

Encryption algorithm

Answer 48

The method for encrypting the plaintext