Computing · Year 9

Active learning ideas

Network Protocols: TCP/IP

Active learning works for TCP/IP because students often view protocols as abstract black boxes. By physically acting out packet exchanges or reconstructing network traces, learners confront misconceptions about reliability and addressing in concrete ways.

• National Curriculum Attainment Targets
• KS3: Computing - Computer Networks
• KS3: Computing - Communication and Collaboration

• 25–45 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Simulation Game
• 35 min · Small Groups

Role-Play: TCP Three-Way Handshake

Divide class into sender, receiver, and router roles. Use printed packet cards to simulate SYN, SYN-ACK, ACK exchanges, including deliberate 'losses' for retransmits. Groups debrief on sequence numbers and reliability after 10 rounds.

Explain the necessity of standardized protocols like TCP/IP for global internet communication.

Facilitation Tip

During the TCP Three-Way Handshake, have students hold numbered packet cards and verbally acknowledge each step before passing the next, reinforcing sequencing and reliability.

What to look for

Provide students with three scenarios: 1) Sending a large file, 2) Streaming a live video, 3) Browsing a website. Ask them to identify which protocol (TCP or UDP, if introduced) is best suited for each and briefly explain why, referencing reliability.

• Apply
• Analyze
• Evaluate
• Create
• Social Awareness
• Decision-Making

Activity 02

• Simulation Game
• 25 min · Small Groups

Packet Relay Race: IP Routing

Teams create paper networks with nodes labeled by IP addresses. Relay packets (envelopes) through paths, noting hops and fragmentation. Discuss routing tables and why standardization prevents errors.

Analyze how TCP ensures data integrity and reliability during transmission.

Facilitation Tip

In the Packet Relay Race, place numbered routers on the floor so students physically trace packet paths and experience how IP addresses determine hops.

What to look for

Ask students to draw a simple diagram showing two computers communicating. They should label the components involved in sending a 'packet' and indicate where TCP and IP play a role in the process.

• Apply
• Analyze
• Evaluate
• Create
• Social Awareness
• Decision-Making

Activity 03

• Simulation Game
• 45 min · Pairs

Wireshark Capture: Real Traffic Analysis

Students install Wireshark, capture HTTP traffic from browsing a site, filter for TCP packets, and annotate handshakes and data segments. Pairs compare captures to predict failures without protocols.

Predict the chaos that would ensue if there were no common network protocols.

Facilitation Tip

When using Wireshark, freeze the capture periodically to ask students to predict what the next few packets will look like based on observed flags and sequence numbers.

What to look for

Pose the question: 'Imagine the internet without any rules for sending information. Describe two specific problems that would occur, relating your answer to how protocols like TCP/IP solve these issues.'

• Apply
• Analyze
• Evaluate
• Create
• Social Awareness
• Decision-Making

Activity 04

• Simulation Game
• 30 min · Whole Class

Chaos Simulation: No Protocols

Provide mixed-format messages (scrambled orders, missing parts). Groups attempt reassembly without rules, then apply TCP rules to succeed. Vote on predicted real-world impacts like failed online banking.

Explain the necessity of standardized protocols like TCP/IP for global internet communication.

What to look for

Provide students with three scenarios: 1) Sending a large file, 2) Streaming a live video, 3) Browsing a website. Ask them to identify which protocol (TCP or UDP, if introduced) is best suited for each and briefly explain why, referencing reliability.

• Apply
• Analyze
• Evaluate
• Create
• Social Awareness
• Decision-Making

A few notes on teaching this unit

Start with the TCP Three-Way Handshake role-play to ground sequence numbers and acknowledgments in embodied memory. Move to the Packet Relay Race to make IP routing tangible before analyzing real traffic in Wireshark. Avoid rushing to abstract diagrams—instead, let students build mental models through movement and artifacts first, then formalize with diagrams and labels.

Successful learning looks like students explaining how TCP’s sequence numbers and acknowledgments prevent data loss, describing why IP addresses get fragmented across routers, and justifying protocol choices for real-world scenarios after hands-on practice.

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Watch Out for These Misconceptions

• During Role-Play: TCP Three-Way Handshake, watch for students treating the handshake as a single step. Redirect by having them chant each SYN, SYN-ACK, and ACK exchange aloud while passing corresponding cards to reinforce the three distinct messages.

  During Packet Relay Race: IP Routing, watch for students assuming IP delivers packets directly to the destination. Redirect by placing a router card between every pair of computers and requiring students to pass packets through each router, showing that IP relies on intermediate hops.

• During Wireshark Capture: Real Traffic Analysis, watch for students equating speed with reliability. Redirect by filtering for retransmitted packets in the trace and asking students to calculate the time lost to retransmissions compared to successful transmissions.

  During Chaos Simulation: No Protocols, watch for students believing hardware alone handles incompatibilities. Redirect by giving groups mismatched rule sets for packet formats and watching their communication break down before introducing TCP/IP rules to restore order.

• During Chaos Simulation: No Protocols, watch for students assuming the internet would still function without standard addressing. Redirect by having groups attempt to route packets using only MAC addresses and observe collisions when multiple devices claim the same address.

  During Role-Play: TCP Three-Way Handshake, watch for students thinking TCP sends entire files at once. Redirect by having them break a mock file into three separate packet cards and reassemble them in order after the handshake completes, demonstrating segmentation and reassembly.

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Methods used in this brief

• Simulation Game