Topic 3 - Networks

Question 1

Client

Answer 1

Computer system or software that requests a service from a server connected to the same network

Question 2

Server

Answer 2

A computer system or software that provides a service to other computer systems on the same network

Question 3

Computer network

Answer 3

Formed when 2 or more computers are linked together. Every computer on the network can send and receive data between themselves.

Question 4

3 types of ways to connect computer systems on a network

Answer 4

Hub - Connection point for all devices on a single network

If data is sent on this, it gets sent to all devices connected to the ports of the hub which is inefficient

Switch - Similar to a hub, but can identify which device is connected to which port making it more efficient since data can be sent only to the computer that needs it

Router - Can connect multiple networks and acts as an intermediary between them

Question 5

Internet

Answer 5

This is a globally connected network that uses the TCP/IP protocol to transmit data. It hosts the webpages that make up the World Wide Web.

Question 6

ISP

Answer 6

Internet Service Providers run and provide networks that provide internet access.

Question 7

IXP

Answer 7

Internet Exchanges. These connect all ISP and internet networks together.

Question 8

Packet

Answer 8

Unit of information that is suitable for travel through a computer network

Question 9

Packet switching and benefit

Answer 9

A file is grouped into packets of data. This file being transmitted through packet switching may be divided into multiple packets. Each packet can take different routes to the same destination based on network availability and guided by routers. Once all at the destination, they are reassembled together.

Packet switching is more efficient

Question 10

What is a packet composed of?

Answer 10

Header:
Contains source and destination addresses, packet number, number of packets and protocol information

Payload:
Data itself

Trailer:
Error checking information (e.g. checksum)

Question 11

Router

Answer 11

This is used to manage traffic across networks. It controls the flow of data packets by checking its addresses and ensuring they are on the correct path to their destination. It also makes sure all transmission occurs securely.

Question 12

LAN

Answer 12

Local Area Network. Covers a single building/less than 1km radius coverage

Question 13

Wide Area Network and 1 example.

Answer 13

Several LANs connected together using multiple routers and covers a radius of more than 1km. An example of this is the Internet.

Question 14

VLAN and benefits

Answer 14

Virtual Local Area Network. This is when a physical LAN is split up into virtual networks using switches in a logical manner. This would make sense for example departments in a business.

They increase the overall security and performance of the LAN.

Question 15

SAN

Answer 15

Storage Area Network. This is a network of storage devices. Not accessible by LAN.

Question 16

WLAN

Answer 16

Wireless Local Area Network. This is essentially a LAN but devices are connected wirelessly by high-frequency data waves called Wi-Fi.

Question 17

2 pros and 2 cons of WLAN

Answer 17

Pros:
- No cables (reduced costs)
- Can move devices around

Cons:
- Security
- Obstructions like walls may slow down speeds

Question 18

PAN

Answer 18

Personal Area Network. This connect devices in a user’s immediate area. This includes things life Wi-Fi hotspots and Bluetooth devices.

Question 19

Intranet

Answer 19

This is sort of like a private version of the internet. Intranet web pages are only accessible from computers on a particular network.

Question 20

Extranet

Answer 20

When an intranet system is accessible through an online portal.

Question 21

VPN process

Answer 21

• From your VPN client, you send all your URL requests to a VPN server
• The VPN server makes a request to that internet resource on your behalf and then returns the response to you via the VPN client

Question 22

2 special tech used in VPN

Answer 22

• Connection with VPN server is secure thanks to encryption
• The process of creating and maintaining an encrypted connection between the server and client is called tunneling

Question 23

What encryption tech is used in VPN?

Answer 23

SSL or TSL

Question 24

2 pros of VPN

Answer 24

Encryption:
Data is not able to be understood by attackers

Tunneling:
Data can be secured using protocols

Question 25

P2P

Answer 25

Peer to Peer networks. Allows two or more computer to share resources with each other without having a central point. Each computer acts as both a client and server.

Question 26

Protocol

Answer 26

A set of rules for data transmission

Question 27

TCP/IP

Answer 27

Rules for transmitting data on the internet

Question 28

HTTPS

Answer 28

Rules for securely transmitting data between a web browser and a webpage’s server.

Question 29

SFTP

Answer 29

Rules for securely transferring files from client to server

Question 30

2 examples of roles of protocols

Answer 30

Maintain data integrity
Prevent deadlock (when 2 packets collide and block each other)

Question 31

OSI Model at least 3 layers and an outline of each

Answer 31

Physical - Layer 1:
Physical structure and medium used to transfer data. For example Fiber Optic network cables and hardware like hubs

Data Link - Layer 2:
Ensures that data sent over the physical layer is reliable and error free techniques like using framing and MAC addressing.

Network - Layer 3:
Manages data deliver to ensure that packets reach their destination.

Question 32

OSI

Answer 32

Open System Interconnection

Question 33

2 examples of types of wired transmission media

Answer 33

Ethernet, Fiber Optic

Question 34

2 examples of wireless transmission media

Answer 34

Radio Waves, Wireless/Wi-Fi

Question 35

Compare 3 points about WiFi and Ethernet

Answer 35

Wifi has slower data transfer speed than Ethernet

WiFi may suffer from signal interference due to environmental factors whilst Ethernet does not.

WiFi is easier to install and deploy while Ethernet’s cable infrastructure can be expensive and time-consuming to install

Question 36

3 things that affect transmission speed

Answer 36

• Traffic
• Environmental issues (like interference)
• Quality of how the network’s infrastructure has been set up

Question 37

Lossy compression

Answer 37

• Removes data to reduce file size
• It is used when some data can be lost

Question 38

Lossless compression

Answer 38

• Uses an algorithm that reorganizes and groups the data to reduce file size (e.g. image)
• Used when no data can be lost (e.g. source code)

Question 39

1FA

Answer 39

1 FFA uses only knowledge factor (e.g. password) for authentication

Question 40

2FA

Answer 40

Uses knowledge factor (e.g password) and possession factor (smartphone) for authentication

Question 41

3FA

Answer 41

Uses knowledge factor, possession factor and inherence factor (e.g. face recognition) for authentication

Question 42

MAC address

Answer 42

A unique code that is used to identify devices on a network. It is comprised of a 12 digit hexadecimal code with the first 6 digits identifying the manufacturer info and the last 6 digits the unique serial number of the device.

Question 43

Firewall

Answer 43

Improves network security by controlling and filtering incoming and outgoing traffic of a network according to predetermined rules (blacklist and whitelist) using MAC addresses.