Unit 3: Network communications

2 dot points across 2 inquiry questions, in syllabus order. Each dot point has a focused answer, with exam-style questions and worked answers where available.

How do layered models and protocols let data travel across networks?

Describe the OSI and TCP/IP models and the role of common protocols at each layer, compare TCP and UDP, and explain packet structure, encapsulation and how packets move between networks

The seven-layer OSI model and four-layer TCP/IP model, which protocols work at each layer (HTTP/S, DNS, SMTP, TCP, UDP, IP, Ethernet), how TCP differs from UDP, what is inside a packet (header, payload, trailer), and how encapsulation moves data through the layers.

8 min read →

How are devices addressed, networks divided and traffic directed?

Explain IPv4 and IPv6 addressing, private and public addresses, subnet masks and subnetting, and the role of gateways, DNS, ports and network components; measure and troubleshoot network performance with tools such as ping and traceroute; interpret and draw network diagrams

IPv4 and IPv6 addresses, private address ranges, subnet masks and CIDR notation, calculating network and broadcast addresses and usable hosts, default gateways, DNS, well-known ports, routers, switches and access points, latency, bandwidth, ping and traceroute, and network diagrams.

9 min read →