IB Computer Science - Network Questions

Flashcards for lesson 4

Outline what is meant by the term computer network

Multiple computers and other computing devices that are linked together through communication channels, such as through cables or by wireless means.

What is the purpose of a computer network?

Allows for a sharing of files and informations between systems and/or users

What is packet switching

Since a large data is hard to sent through the network, a data from one computer is divided into “packets”. This process is called “packet switching”

What is in a packet?

• Segmented data

• Source address and Destination Address

• Sequencing information

Describe how data is transmitted through packet switching.

In packet switching, data is broken into smaller units called packets before transmission. Each packet contains a header (with source, destination, and sequencing information) and a payload (the actual data). The packets travel independently through different routes across the network based on availability. Once they arrive at the destination, they are reassembled in the correct order using sequencing information. This method improves efficiency and reduces congestion compared to circuit switching.

A company decided to allow the teachers to use their own devices in its training room by adding wireless networking.

3a) Outline one advantage to the company.

One advantage of this is that it would minimize the hardware costs for the company.

A company decided to allow the teachers to use their own devices in its training room by adding wireless networking

3b) Outline one disadvantage.

This is a increased security risk, as personal devices may have malware or unauthorized software that could compromise the network.

A company decided to allow the teachers to use their own devices in its training room by adding wireless networking

3c) Describe one method of security that may be used on this wireless network

One method of security that may be used on this wireless network is encryption, which allows data to be transmitted safely, as even when the data is intercepted it would be unreadable. Symmetric enctription would work better as it is suitable and effecient for larger types of data.

A company decided to allow the teachers to use their own devices in its training room by adding wireless networking

3d) Explain why the speed of data transmission on the wireless network in the training room may vary.

The speed of data transmission may vary due to signal interference from other electronic devices or physical obstacles like walls. Network congestion can also occur if too many users are connected, reducing bandwidth per device. Additionally, the distance from the router affects signal strength, with devices farther away experiencing slower speeds. Finally, differences in device capabilities, such as older Wi-Fi adapters, can impact connection speeds.

Outline one reason why protocols are used in communications between computers.

Protocols ensure standardized communication between computers by defining rules for data transmission, allowing different devices to send and receive data correctly.

Outline two advantages of a school using a computer network

1. Efficient Resource Sharing – A computer network allows students and teachers to share resources such as files, software, printers, and internet access. This reduces costs and ensures that everyone has access to the necessary educational tools without needing individual copies.

2. Improved Communication and Collaboration – Networks enable seamless communication through emails, messaging platforms, and shared workspaces. Students and teachers can collaborate on projects, access learning materials from anywhere, and streamline administrative tasks, enhancing the overall learning experience.

Router

A router is a device that takes the digital signal from a modem, and it routes the information to multiple devices that are connected to the router. This helps to create a LAN, and often can be done wirelessly

Network Interface Card (NIC)

A network interface card is a computer hardware component that connects a computer to a computerr network, and enables data to be sent and recieved between the computer and other network-connected devices.

Outline two measures that a school could take to safeguard it’s data from unlawful access via the internet.

Firstly their network could be equipped with a firewall feature that restricts access to only those who have permmision and maintaining a log of activities. In addition The school could also use Network encryption so that should data within the system be intercepted, it cannot be understood without being decoded.

A school currently has a cabled network but wants to add wireless networking across the whole campus.

10a) Describe two hardware components the school will need to implement the wireless network.

The school would need a Wireless Access Point, wich would allow students and staff to connect to the wifi wirelessly as well as a wireless router which connects the school's network to the internet and manages data traffic between wired and wireless devices. It assigns IP addresses, directs data packets, and ensures secure connections for users accessing the network.

A school currently has a cabled network but wants to add wireless networking across the whole campus.

10b) Identify two advantages to the students of the new wireless network

This allows for increased convenience for data sharing, as well as easier access to online reasources.

There are concerns that unauthorized people could access the data on the wireless network.

10c. Outline two methods the school could employ to prevent network data from being accessed over their wireless system.

The school has decided to implement a virtual private network (VPN) to provide access to it’s network.

10d) Identify two technologies the school would require to provide a VPN

It would require a VPN Server and a VPN Client Software

The school has decided to implement a virtual private network (VPN) to provide access to its network

10e) Explain one benefit to the staff of using a VPN remotely to access the school network.

One benefit would be that using a VPN remotely to acess the schools network can be safely accessed from any location. This allows them to acces files, drives and other online materials from home, vacations and any other location other than the school.

The school has decided to implement a virtual private network (VPN) to provide access to its network

10f) Identify two features of a VPN that make it secure

1. Strong Encryption - Uses strong encryption protocols to convert data into an unreadable format during transmission. this ensures that even if data is intercepted, it cannot be read without a decryption key

2. Provides Privacy - A VPN hides the user’s IP address

Identify two reasons why fibre opptics cable would be preferred over wireless connectivity.

They offer a greater speed and can be used for longer amounts of distances . In addition it is also less susceptible to interference and signal degradation.

Identify 2 differences between LAN and WAN

WAN creates a network of devices NOT localized in terms of geographical area, whereas LAN is often found in single homes under one roof. LAN typically offers higher speed for a lower cost whereal WAN offers slower speed for a higher cost due to external network use.

Distinguish between a wired network and a wireless network in terms of reliability of transmission.

Wired network is typically more reliable as it requires a physical wire connection to transmit data, making it less prone to interference and data loss, as well as other issues that may arise with a wireless connection. A wireless connection relies on radio waves which can cause issues due to factors such as distance and walls. In addition it is more succeptible to interference as the data transferrs and transmissions are not passing through physical channels.

Outline why a wireless network may be less secure than a wired network

Wireless networks run the risks of being less secure as they are more succeptible to interference as it easier to gain unauthorized access and therefore runs a higher risk of cyber attacks

What are 2 technologies that are required to provide a VPN

VPN Server and VPN Client Software

What are 2 factors that may affect the speed of data transmission

File size and network Bandwidth

What is data compression

bit-rate reduction making the data require fewer bits that it origionally did

Why is data commpression used when data is transmitted

1. Faster Transmission – Compressed files are smaller in size, reducing the amount of data that needs to be sent, which speeds up transmission over networks.

2. Reduced Bandwidth Usage – By decreasing file size, compression helps minimize network congestion and allows more efficient use of available bandwidth.

3. Lower Storage Requirements – Compressed data takes up less space on storage devices, making it easier to store and manage large amounts of information.

How is encryption used to protect data

Encryption makes readable data unreadable unless you have a key there are 2 types symmetrical and Asymmetrical. Both of these allow data to be transmitted safely even if the data has been intercepted.

What is a firewall

A network security device or a software that performs multiple tasks like monitoring users and incoming and outgoing traffic, restricting access to those who have passwords and creates a log of activity.

Two layers of Open Systems Interconnection (OSI)

Application layer - 7

• Human to computer interaction layer

Presentation layer - 6

• Ensure that the data is in a useable format

Identify one cause of data loss

Harware Faliures such as a faulty router

3 peices of information that a data packet must contain

Segment Data, Source address and destination address and sequencing information

prevent data loss

Make sure that your harware is up to date and does not have any flaws. Make sure that your data transmission channels are secured and encrypted.

2 charactaristics of fibre optics

wired communication that utilizes light instead of electromagnetic waves/electrical signals

2 characteristics of wireless transmission

Uses radio waves and are succeptible to interference