This is a beta course, so its structure, chapters, and examples may continue to change.
Computer Networks
The course follows one packet from the cable to the application. It starts at the bottom, with how bits actually cross a medium, and moves upward through the five-layer architecture until the moment a browser sends a request and a server answers it.
The six chapters follow that path in order:
- Network Architecture — what a computer network is, the metrics that describe its performance, the OSI and TCP/IP models, and the devices that implement each layer.
- Physical Layer — transmission theory, encoding and modulation, switching techniques, transmission media, and the hardware that repeats and concentrates signals.
- Data Link Layer — framing, error control, flow control and reliable transmission, medium access control, LAN and WAN protocols, and bridges and switches.
- Network Layer — interconnection of heterogeneous networks, routing algorithms, IPv4 and IPv6, routing protocols, multicast, and mobile IP.
- Transport Layer — process-to-process communication, ports, the UDP and TCP protocols, connection management, and flow and congestion control.
- Application Layer — network application models, DNS, FTP, electronic mail, and the WWW and HTTP protocols.
Each chapter ends with exercises and reference answers, and a syllabus page collects the assessment objectives and the examination scope.
- Read a layered design on sight: place any protocol, header field, or device in the OSI or TCP/IP stack and say what problem it solves.
- Work through a packet end to end: follow an HTTP request from the browser, through the transport, network, and link layers, to the server and back.
- Explain the reliability mechanisms: sequence numbers, acknowledgements, retransmission, the sliding window, and how flow control differs from congestion control.
- Compare protocols on evidence: TCP against UDP, HTTP against FTP, SMTP against POP3 and IMAP, recursive against iterative DNS queries.
- Recognise the failure modes: a stalled connection, a head-of-line block, a spoofed SYN, a stale DNS cache entry, and what each layer does about it.
- Students preparing for a computer networks course or the corresponding postgraduate entrance examination, who want the syllabus mapped onto readable notes.
- Developers and engineers who need to reason about sockets, ports, timeouts, and protocol behaviour rather than treat the network as a black box.
- Anyone who has used HTTP, DNS, FTP, or SMTP for years and wants the mechanism behind the tools.
- Readers with no networking background: every term is defined where it first appears, and the layer-by-layer order means no chapter assumes knowledge from a later one.