Computer Networking
Key Ideas and Definitions
DoD TCP/IP Model.
• The DoD TCP/IP model is a networking framework that standardizes communication protocols and data transfer across networks.
• It consists of four layers: Application, Transport, Internet, and Network Access.
Application Layer.
• Provides services for applications like web browsing and email, handling data formatting, encryption, and session control between end-users and networks.
• Example protocols: HTTPS, FTP, SMTP.
Transport Layer.
• Responsible for reliable data transmission, error checking, and sequencing; breaks messages into packets and reassembles them at the destination.
• Key protocols: TCP (reliable delivery), UDP (fast, less reliable).
Internet Layer.
• Manages logical addressing and routing, ensuring packets reach the correct destination across networks.
• Key protocols: IP, ICMP, ARP.
Network Access Layer.
• Handles the physical connection to the network, media access, and hardware addressing.
• Protocols: Ethernet, Wi-Fi.
IP Address.
• A unique numerical identifier assigned to each device on a network, used for addressing and routing.
Subnet Mask.
• A 32-bit number dividing an IP address into network and host portions, determining which devices are on the same subnet.
IPv4 and IPv6.
• IPv4: 32-bit addresses with about 4.3 billion possible values, written in dotted-decimal notation.
• IPv6: 128-bit addresses with a massive address range, colon-hexadecimal notation, and built-in security.
Router.
• A device that connects multiple networks and routes data packets based on IP addresses. Operates at the Internet Layer (Layer 3).
• Connects devices within a LAN, forwarding data based on MAC addresses and segmenting networks for better performance.
Wireless Access Point (WAP).
• Provides wireless connectivity within a network, converting signals between wired and wireless devices. Works at layers 1 and 2.
• Security system that monitors and controls network traffic according to security rules, preventing unauthorized access.
Firewall.
• Used to secure networks by controlling access to the network, blocking unauthorised traffic, detect malicious traffic, and provide protection against threats such as viruses, worms, and hackers
• operates at application and transport layers
Transmission Media.
• The physical channel for data travel: copper cables (UTP), fiber optics, wireless (Wi-Fi, satellite).
• Media type impacts speed, cost, range, and reliability.
Modem.
• Converts digital data from computers into signals for transmission over telephone lines and vice versa.
Network Security.
• Measures to protect a network from unauthorized access or attacks, maintaining confidentiality, integrity, and availability.
Need for Preventing Unauthorised Access.
• important to protect sensitive information and maintaining confidentiality, integrity, and availability of network resources
• can come from external sources like hackers or internal sources like employees with malicious intent
Role of Operating Systems in Network Security.
• They offer various security features such as firewalls, access controls, and encryption.
• can be configured to receive updates and patches, which help to protect against new security threats
• can provide secure methods for remote access and management of device which can reduce the risk of unauthorised access
Bandwidth.
• The maximum rate of data transfer across a network. Higher bandwidth equals faster data transmission.
Network Design.
• The arrangement and selection of devices, connections, and structure that impacts performance and reliability.
Data Collisions.
• Occur when devices transmit data simultaneously, causing corrupted data and delays.
Broadcast Traffic.
• Network packets sent to all devices in a segment. Excessive broadcast reduces performance.
API (Application Programming Interface).
• APIs serve as interfaces for software interaction, allowing different systems to communicate effectively
• Enables applications to work together seamlessly
• Works by defining a set of rules and protocols that allow different software components to request and exchange data or functionality
Ethical Implications.
• Privacy Violations
Example: Developing an app that collects user data (location, messages, contacts) without clearly informing users or obtaining consent.
• Bias and Discrimination
Example: Creating an AI hiring tool that unintentionally favours candidates of a certain gender or race due to biased training data.
• Failure to Ensure Safety or Reliability
Example: Releasing software for self-driving cars without adequate testing, leading to potential harm or fatalities.
Legal Implications.
• Intellectual Property Infringement
Example: Using copyrighted code, images, or libraries without permission or proper licensing.
• Non-Compliance with Data Protection Laws (e.g., GDPR, CCPA)
Example: Failing to provide users with the right to delete their data or not reporting a data breach in a timely manner.
• Software Liability
Example: A bug in medical software causes incorrect dosages to be administered, resulting in legal action against the developer or company.
Syllabus
Knowledge
• API (application programming interface)
▪ purpose of an API
▪ use of an API when developing software
Ethical and legal implications of software development:
Knowledge
• concepts associated with piracy and copyright, including:
▪ intellectual property
o plagiarism in relation to the acknowledgement of code
o Australian copyright laws
o purpose of software licensing
o open source
o proprietary
Network Communications
Models of networking:
Knowledge
• purpose of Department of Defence Transmission Control Protocol/Internet Protocol (DoD TCP/IP
model)
• layers of DoD TCP/IP model
▪ application
▪ transport
▪ internet
▪ network
• role of layers within the model
• key protocols associated with layers
• role of IP addresses
• role of subnet masks
• key differences between IPv4 vs IPv6
Network components:
Knowledge
• the function of networking components at different layers of TCP/IP model
▪ transmission media (UTP, fibre optics, wireless)
▪ modem
▪ router
▪ switch
▪ wireless access point
▪ firewall
Network security:
Knowledge
• need for preventing unauthorised access to a network
• role of firewalls in securing networks
• role of operating systems in network security
Network performance:
Knowledge
• factors that affect network performance:
▪ bandwidth
▪ network design
▪ data collisions
▪ excess broadcast traffic
Skills:
• create logical network diagrams using the CISCO network diagrammatic conventions to represent
network topologies for LAN, WLAN and WAN