Lesson Plan

• Describe the three main sections of a network packet (header, payload, trailer).
• Identify common header fields and explain their purposes.
• Explain how the trailer provides error‑checking information.
• Analyse how packet structure supports routing, flow control and reliability.
• Apply knowledge by correctly labeling a packet diagram.

• Projector or interactive whiteboard
• Slide deck with packet diagram
• Handout containing a blank packet layout and field table
• Whiteboard and markers
• Laptops with network simulation software (e.g., Packet Tracer)
• Sticky notes for quick checks

Start with the question, “How does the internet send a large file from one computer to another?” Review students’ prior knowledge of data transmission, then state today’s success criteria: students will be able to break down a packet into header, payload and trailer and explain the role of each part.

1. Do‑Now (5'): Students write a quick definition of “packet” on sticky notes; teacher collects for a brief poll.
2. Mini‑lecture (10'): Present the three‑section model and key header fields using slides and a labelled diagram.
3. Guided practice (12'): In pairs, students label a blank packet diagram handout while the teacher circulates, asking probing questions.
4. Interactive simulation (10'): Use Packet Tracer to construct a simple IP packet, inspect header fields, TTL and checksum.
5. Check for understanding (8'): Quick Kahoot quiz on field purposes and trailer function.
6. Summary & reflection (5'): Class creates a collective mind map of why packet structure matters.

Recap the three packet sections and their functions, then ask students to write one “take‑away” on an exit ticket. Collect the tickets and assign a short homework: research how a different protocol (e.g., UDP) modifies the packet structure.