Computer Networks · TEE · papers
Q1B · TCP/IP reference model
Re-exam · 4 February 2026
TEE · Actual TEE paper · all questions · current syllabus 702AI0C023
Actual PYQ · Q1B. Draw the labelled diagram of the TCP/IP reference model and explain the task of all layers. [5 marks]
Answer
Diagram: OSI layers mapped to the four-layer TCP/IP model. Labels: OSI layers mapped to the four-layer TCP/IP model | OSI layers mapped to the four-layer TCP/IP model | 7 Application | 6 Presentation | 5 Session | 4 Transport | 3 Network | 2 Data link | 1 Physical | Application | HTTP, DNS, FTP, SMTP | Transport | Internet | Link / network access | Includes physical access | Some textbooks split link into data link + physical: five layers.
| Layer | Task | Examples |
|---|---|---|
| Application | Defines application message formats and exchanges for Web access, naming, email and file transfer; includes presentation/session functions as needed | HTTP, DNS, SMTP, FTP |
| Transport | End-to-end process communication | TCP, UDP, SCTP |
| Internet | IP addressing, routing and best-effort datagrams | IPv4/IPv6 |
| Link/network access | Local delivery and physical access | Ethernet/Wi-Fi and their medium |
Here the four-layer convention includes physical access within the link layer. A five-layer textbook diagram may split physical from data link; label which convention is being used.
Source: Re-exam · 4 February 2026, original question paper page 1. Original marks retained; solution independently authored.