International Baccalaureate IB Computer Science

Describe the purpose and characteristics of networks.
- Networks: local area network (LAN), wide area network (WAN), personal area network (PAN), virtual private network (VPN).

Describe the purpose, benefits and limitations of modern digital infrastructures.
- Modern digital infrastructure: the internet, cloud computing, distributed systems, edge computing, mobile networks
- Examples where specific networks are used may include the worldwide web (WWW), cryptocurrency blockchains, smart traffic lights, a school.

Gateways, hardware firewalls, modems, network interface cards, routers, switches, wireless access points.
- How devices map to the layers of the TCP/IP model.

Describe the network protocols used for transport and application.
- Protocols: transmission control protocol (TCP), user datagram protocol (UDP), hypertext transfer protocol (HTTP), hypertext transfer protocol secure (HTTPS), dynamic host configuration protocol (DHCP).

Describe the function of the TCP/IP model. (HL only)
- Application, transport, internet, network interface
- The role of each layer and the interaction between these layers to ensure reliable data transmission over a network

Describe the functions and practical applications of network topologies.
- Network topologies: star, mesh, hybrid
- Factors to consider must include reliability, transmission speed, scalability, data collisions, cost.
- Examples may include home and small office settings, where reliability is paramount, and the use of networks in larger settings (e.g. corporations, government departments, college campuses).

- Types of servers: domain name server (DNS), dynamic host configuration protocol (DHCP), file server, mail server, proxy server, web server
- Factors to consider must include function, scalability, reliability and security.

- Client-server and peer-to-peer models
- The respective benefits and drawbacks of client-server and peer-to-peer models
- Real-world applications may include web browsing, email services, online banking, file sharing, VoIP services, blockchain.

Explain the concepts and applications of network segmentation.
- Segmentation for network performance and security, to reduce congestion, to manage network resources efficiently
- Network segmentation must include the uses and roles of segmenting, subnetting and virtual local area networks (VLANs).

- The distinction between IPv4 and IPv6 addressing
- The differences between public IP addresses and private IP addresses, and between static IP addresses and dynamic IP addresses
- The role of network address translation (NAT) to minimise the use of IP addresses and to facilitate communication between private internal networks and the public internet.

Compare types of media for data transmission.
- Wired transmission via fibre optic cables and twisted pair cables
- wireless transmission
- The advantages and disadvantages of these three types of data transmission
- Factors to consider must include bandwidth, complexity of installation, cost, range, susceptibility to interference, attenuation, reliability, security.

Explain how packet switching is used to send data across a network.
- The process of segmenting data into packets with a routing header attached, and independently transmitting control information, allowing the data to be reassembled at the destination
- The role that switches and routers play in packet switching.

Explain how static routing and dynamic routing move data across local area networks. (HL only)
- The process of static routing, and its advantages and disadvantages
- The process of dynamic routing, and its advantages and disadvantages (explanation of a specific routing protocol is not required)
- Factors to consider must include configuration, maintenance, complexity, resource usage, convergence, scalability, network size.

Discuss the effectiveness of firewalls at protecting a network.
- The function of firewalls in inspecting and filtering incoming and outgoing traffic based on whitelists, blacklists and rules
- The strengths and limitations of firewalls
- The role of NAT to enhance network security.