IB Computer Science SL/HL Topic 3 Networks

All networking terms for topic 3 of IB Computer Science.

Network

A connection of two or more computers to enable data sharing. Networks evolved from early single-room setups to larger, interconnected areas, leading to the creation of the World Wide Web by Tim Berners-Lee in 1989, which uses protocols like HTTP and HTML.

World Wide Web (WWW)

A system of protocols, languages, and web pages accessible over the Internet, distinct from the Internet itself, which is the physical network enabling data transfer.

Local Area Network (LAN)

A network within a limited geographic area (e.g., a building) used to share resources like printers and files, sometimes connected to the Internet via a web server.

Virtual Local Area Network (VLAN)

A network subdivision within a LAN, logically grouping devices regardless of physical location, to control traffic and enhance security across both small and large areas.

Wide Area Network (WAN)

A network spanning large geographic regions, such as cities or countries, facilitating resource sharing and communication over long distances.

Wireless Local Area Network (WLAN)

A wireless version of LAN using radio signals to connect devices in areas like homes or offices, commonly providing Internet access to laptops and mobile devices.

Personal Area Network (PAN)

A small network that connects devices within a person's close range, typically for short-distance communications among devices like smartphones, tablets, or wearables.

Virtual Private Network (VPN)

A secure connection over a public network, enabling remote access to private networks and securing data transmission for remote workers or travelers.

Storage Area Network (SAN)

A high-speed network providing centralized access to large data storage devices, commonly used in enterprise settings for efficient data management.

Network Topology

The configuration of network connections. Common types include Ring, Bus, Star, Mesh, and Hybrid, each with unique benefits in managing data flow and redundancy.

Router

A device that forwards data between IP addresses, typically linking an ISP connection to client devices, managing the transfer of web data to correct devices.

Access Point

A device in a network that distributes network access to users, enabling wireless connectivity in areas such as offices and public spaces.

Gateway

A network component that connects networks using different protocols, enabling communication and compatibility across diverse network architectures.

Switch

A device that directs data to its specific destination within a network, improving efficiency by routing data only to the intended recipient, unlike older hubs.

Hub

A network device connecting multiple devices by broadcasting data to all ports, less commonly used today due to security and efficiency improvements in switches.

Bridge

A device that links different transmission mediums, such as copper and optical cables, often used to connect buildings in a network infrastructure.

Workstation

Any computer connected to a network, often used for tasks that require network resources or data access.

Node

Any device or computer that is part of a network, capable of sending or receiving data.

Internet Service Provider (ISP)

A company that provides users access to the Internet, enabling connectivity and data transfer.

Server

A powerful computer in a network managing data flow and device management, crucial for resource sharing and software updates across devices.

Proxy Server

A specialized server that manages data flow between a LAN and a WAN, filtering and storing data to improve network speed and security by reducing repetitive external requests.

Network Standards

Rules and guidelines that ensure compatibility and efficient operation across network devices, crucial for interoperability, reliability, scalability, security, and innovation.

Interoperability

The ability of devices from different manufacturers to work together within a network, ensuring a broad range of device choices and integration.

Reliability

Ensuring network components work consistently as expected, reducing compatibility issues, failures, and downtime by adhering to established standards.

Scalability

The capacity of a network to grow without needing major infrastructure changes, allowing adaptability to new technologies or organizational needs.

Security Standards

Guidelines for implementing protective measures against cyber threats and unauthorized access, essential for safeguarding networked environments.

OSI Model

A theoretical model with seven layers (Physical, Data Link, Network, Transport, Session, Presentation, and Application) describing data transmission between networked devices.

Physical Layer

The OSI layer responsible for the physical connection of devices, managing raw data transmission over media like copper cables, fiber optics, or wireless signals.

Data Link Layer

Ensures reliable data transfer between two directly connected nodes, managing error detection, correction, and flow control.

Network Layer

Manages data routing between different networks, handling address assignment, packet forwarding, and network traffic management.

Transport Layer

Provides reliable, end-to-end communication between applications on separate devices, supporting flow control and error correction.

Session Layer

Establishes, manages, and terminates communication sessions between applications, handling the start, maintenance, and end of a data exchange session.

Presentation Layer

Responsible for data format translation and encryption/decryption, ensuring data is in a usable form for the application layer.

Application Layer

The OSI model's top layer, offering services to applications such as email, web browsing, and file transfer by interfacing with network resources.

VPN Security

VPNs encrypt data between client and server to prevent unauthorized access, especially useful for safeguarding sensitive information over public networks.

VPN Privacy

VPNs conceal the user's IP address and location, helping protect online activity from tracking and promoting user privacy.

VPN Remote Access

Allows secure remote access to private networks, enabling employees to work from diverse locations while maintaining data security.

VPN Cost Savings

Provides a cost-effective alternative to dedicated private networks, reducing the need for leased lines while maintaining secure communications.

VPN Tunneling

The process of encapsulating data in another protocol for secure transmission over insecure networks, enhancing privacy and data integrity in VPNs.

Tunneling Process

Establishes a connection between devices, encapsulates data in a new packet, encrypts it, transmits it through a secure channel, and decrypts it upon arrival.

VPN Protocols

Specific methods (e.g., OpenVPN, IKEv2) enabling secure connections between VPN clients and servers, essential for maintaining private, encrypted communications.

Data Transmission

The process of sending data from one device to another over a network. This involves breaking data into smaller units called packets, which are sent across the network to the destination.

Data Packets

Small units of data used in network transmission. Each packet contains a header with routing information, a payload with the actual data, and a trailer for error checking.

Packet Header

The section of a data packet containing information such as the source and destination addresses, sequence number, and error detection codes, allowing the packet to be routed correctly.

Packet Payload

The part of a data packet that holds the actual data being transmitted, which can be text, images, or other digital information.

Packet Trailer

Contains error-checking data, such as CRC values, to help verify the integrity of the packet upon arrival at the destination.

Packet Switching

A network method where data is broken down into packets, each potentially taking a different route to the destination. Upon arrival, packets are reordered and checked for errors before reassembly.

Router Role in Packet Switching

A router directs each packet to its destination, determining the most efficient route based on current network conditions, which may result in packets arriving out of order.

Protocols

Standardized rules for data transmission, ensuring devices from different manufacturers communicate effectively, securely, and efficiently over a network.

Protocol Compatibility

Protocols allow devices with different technical specifications from various manufacturers to communicate, ensuring broad device integration in networks.

Protocol Efficiency

Protocols specify efficient data transmission methods, minimizing delays and errors to improve network performance.

Protocol Reliability

Ensure that data reaches the correct destination intact and in the correct sequence, protecting against data loss or corruption.

Protocol Security

Provide encryption, authentication, and access control, securing data against unauthorized access and potential cyber threats.

Data Integrity in Protocols

Techniques used in protocols to ensure data is transmitted accurately and without corruption, employing methods like checksums and redundancy.

Flow Control in Protocols

Manages the rate of data transmission to prevent network congestion and overload, maintaining smooth data flow.

Deadlock Prevention

Protocols prevent network standstills caused by devices waiting for access to the same resources by setting rules for resource management.

Congestion Management

Techniques in protocols for controlling data flow during high traffic to prevent network slowdowns, often using packet prioritization and traffic shaping.

Error Checking

Methods such as checksums and cyclic redundancy checks used in protocols to detect and correct transmission errors, ensuring accurate data delivery.

Transfer Speed Factors

The speed of data transfer on a network is influenced by bandwidth, network congestion, distance, network type, and device performance.

Bandwidth

Refers to the maximum amount of data that can be transmitted over a network in a set period. Limited bandwidth slows down data transmission speeds.

Network Congestion

Occurs when network traffic exceeds capacity, leading to slower data speeds, especially during peak usage times.

Distance and Transmission Speed

Longer distances can introduce delays and slower data speeds due to signal attenuation and interference, particularly in wireless networks.

Network Type and Speed

Wired networks like Ethernet generally offer faster speeds than wireless networks due to stable physical connections and less susceptibility to interference.

Network Devices and Speed

Routers, switches, and modems can impact network speed; older or slower devices may bottleneck data transmission.

Data Compression

Reduces data size for faster transmission over networks, conserving bandwidth and storage, often essential for transferring large files efficiently.

Bandwidth Optimization via Compression

Compression reduces the amount of data transmitted, helping avoid network congestion and improving transmission efficiency.

Cost Savings via Compression

Reducing data size through compression minimizes transmission costs, particularly valuable for organizations with high data transfer needs.

Improved User Experience with Compression

By reducing data size, compression decreases transmission time, enhancing user experience and productivity, especially on slower networks.

Optical Cable

A high-speed data transmission medium using light pulses over fiber optics, ideal for long-distance data transfer due to high bandwidth and resistance to interference.

Copper Twisted Pair Cable

Commonly used in local networks (e.g., Cat5 or Cat6 cables), consisting of twisted copper wires to reduce interference, but less secure and slower over long distances.

Coaxial Cable

A type of copper cable with layers of insulation and shielding, used for high-frequency transmission, though prone to damage and less secure than fiber optic.

Crosstalk

Interference between adjacent cables, commonly mitigated by using twisted pairs or shielded cables to minimize data corruption and maintain transmission quality.

Wireless Network Advantages

Wireless networks provide greater mobility, flexibility, and accessibility than wired networks, allowing users to connect from various locations within the signal range. They are often less expensive to install and maintain and are easily scalable for growing network needs.

Wireless Network Disadvantages

Wireless networks face security risks from unauthorized access, potential interference, limited range, lower speeds compared to wired networks, and compatibility issues with certain devices.

Guided vs. Unguided Medium

In guided (wired) media, data is directed to a specific location, whereas unguided (wireless) media broadcasts signals in all directions within a range, allowing users within reach to connect without a specific path.

Radio Frequency Categories

Data is wirelessly transmitted in three frequency bands. Radio (3KHz-3GHz), Microwave (3-300GHz), and Infrared (300GHz-400THz). Each frequency range has unique properties affecting transmission range, penetration, and application suitability.

Radio Transmission

Uses a low frequency range of 3KHz to 3GHz for broad coverage. It can pass through walls, making it widely used for long-distance communication.

Microwave Transmission

Operates in the 3-300GHz range with higher frequency than radio, allowing greater data capacity but is more affected by line-of-sight and obstacles, suitable for specific high-bandwidth applications.

Infrared Transmission

Uses a high frequency range (300GHz-400THz) but is limited by obstacles, as it cannot penetrate walls. Ideal for secure, short-range communication, such as home TV remotes or line-of-sight devices.

WiFi

A common wireless technology operating around 2.4-5 GHz, ideal for homes and workplaces, with a moderate wall penetration ability and a range of about 100 meters, depending on environmental conditions.

WiMax

Provides greater range than WiFi (up to 30km) with a wall-penetrating capability and speeds up to 70Mbps, suitable for long-range wireless connections in rural or expansive areas.

LiFi (Light Fidelity)

A high-speed wireless technology using LED lights for data transmission at around 200Gbps. LiFi requires line-of-sight, as signals cannot pass through walls, and is highly secure due to limited signal leakage.

Bluetooth

Short-range wireless technology operating around 2.5GHz, used for device pairing and low-energy data transfer. It’s commonly found in personal devices like speakers, headphones, and wearable technology.

Wireless Access Point (WAP)

A device that connects wireless devices to a wired network, transmitting data over radio waves and acting as the interface between the network’s wireless and wired segments.

Network Interface Card (NIC)

A hardware component that enables a device to connect to a wireless network, often built into laptops, tablets, and smartphones but sometimes added to desktop computers.

Router in Wireless Networks

Connects multiple networks, directs traffic, and acts as a gateway between wired and wireless networks, enabling data flow across network types.

Switch in Wireless Networks

Connects devices on a network, directing traffic within a network and linking wireless access points to the wired infrastructure.

Operating System (OS) Role in Wireless Networking

The OS provides device-level support for wireless connectivity, ensuring compatibility and managing wireless network settings and protocols.

Network Protocols in Wireless Networks

Define rules for data transmission over wireless networks, such as Wi-Fi, Bluetooth, and Zigbee, enabling compatible communication between devices.

Wireless Network Management Software

Used for configuring, managing, and monitoring wireless network components like access points and security settings to maintain network health.

Network Security Software

Protects wireless networks from unauthorized access and cyber threats using tools like firewalls, antivirus programs, and intrusion detection systems.

Wireless Network Encryption

A security measure encoding data so that only authorized users can access it, with common standards like WEP, WPA, and WPA2 to prevent interception by unauthorized users.

Encryption Advantages

Provides high security by encoding data for authorized access, supports various encryption standards, and is easy to implement on most wireless networks.

Encryption Disadvantages

Older methods like WEP are vulnerable, encryption can reduce performance, and keys or passwords need regular updates to maintain security.

Authentication in Wireless Networks

Verifies user identity before accessing the network, using methods like passwords, certificates, and biometric scans, often in combination with encryption for added security.

Authentication Advantages

Provides secure user verification, supports multiple authentication methods, and strengthens overall network security when combined with encryption.

Authentication Disadvantages

Can be vulnerable to password attacks and phishing, strong methods like biometrics may be costly, and methods require regular updates to remain secure.

Access Control in Wireless Networks

Limits network access to authorized devices, using techniques like MAC address filtering, network segmentation, and VPNs to prevent unauthorized access.

Access Control Advantages

Helps prevent unauthorized access to the network and resources, is generally easy to implement, and supports multiple security policies.

Access Control Disadvantages

Vulnerable to MAC address spoofing, can be challenging to manage in large networks, and complex to configure and troubleshoot.