Computer Science · Grade 10

Active learning ideas

TCP/IP and Packet Switching

Active learning builds lasting understanding for TCP/IP and packet switching because the process of breaking, routing, and reassembling data is invisible without concrete models. When students manipulate physical packets, simulate network conditions, and analyze real traffic, they move from abstract concepts to operational knowledge that reflects how networks actually function.

• Ontario Curriculum Expectations
• CS.HS.N.3
• CS.HS.N.4

• 25–50 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Simulation Game
• 35 min · Small Groups

Card Sort: Packet Transmission

Divide a message into packets on cards with sequence numbers and fake IP addresses. Shuffle cards and have groups act as routers to pass them along varied paths. Reassemble at the end, discussing fixes for missing or out-of-order packets.

Explain how data is broken into packets and reassembled at its destination.

Facilitation Tip

During Card Sort: Packet Transmission, have students work in pairs to reassemble messages from scrambled headers and payloads, forcing them to notice how sequence numbers and checksums enable reconstruction.

What to look for

Present students with a scenario: 'A video call is experiencing choppy audio and frozen video.' Ask them to identify which TCP/IP component (TCP or IP) is most likely struggling and explain why, referencing packet loss or reordering.

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

Activity 02

• Simulation Game
• 45 min · Pairs

Packet Tracer: Network Build

Use Cisco Packet Tracer to create a simple network with PCs and routers. Send pings or files, then inspect packet paths and TCP handshakes in simulation mode. Groups modify topologies to observe rerouting.

Analyze the role of TCP and IP in ensuring reliable data transmission.

Facilitation Tip

In Packet Tracer: Network Build, ask groups to introduce deliberate packet loss by adjusting link congestion settings, then challenge them to explain why TCP retransmissions occur.

What to look for

On an index card, have students draw a simple diagram showing a message being broken into three packets, labeled A, B, and C. Then, ask them to write one sentence explaining how TCP ensures these packets are reassembled correctly at the destination.

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

Activity 03

• Simulation Game
• 50 min · Pairs

Wireshark: Traffic Capture

Install Wireshark and capture HTTP traffic from browsing sites. Filter for TCP/IP packets, color-code by conversation, and analyze headers for sequence numbers and acknowledgments. Pairs present findings on reliability features.

Predict what happens when data packets are lost or arrive out of order.

Facilitation Tip

While using Wireshark: Traffic Capture, pause captures mid-stream to ask students to predict which packets might arrive out of order and how TCP handles it.

What to look for

Facilitate a class discussion: 'Imagine the internet was built using circuit switching instead of packet switching. What would be the biggest challenges for streaming video or making multiple phone calls simultaneously? How does packet switching solve these issues?'

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

Activity 04

• Role Play
• 25 min · Whole Class

Role Play: Packet Loss Scenario

Assign roles as sender, receiver, and routers; sender breaks data into packets. Routers 'lose' some packets randomly. Receiver requests retransmits, showing TCP recovery. Debrief on error handling.

Explain how data is broken into packets and reassembled at its destination.

What to look for

Present students with a scenario: 'A video call is experiencing choppy audio and frozen video.' Ask them to identify which TCP/IP component (TCP or IP) is most likely struggling and explain why, referencing packet loss or reordering.

• Apply
• Analyze
• Evaluate
• Social Awareness
• Self-Awareness

A few notes on teaching this unit

Teachers guide students to separate the roles of IP and TCP early, using layered metaphors like postal mail (IP as addresses on envelopes) and registered mail (TCP as tracking and confirmation receipts). Avoid teaching TCP reliability as automatic; instead, let students experience packet loss through simulations so they understand why retransmissions matter. Research shows that students grasp fragmentation and reassembly better when they physically cut and reassemble messages than when they only see diagrams.

Students will explain how IP addresses guide packets through routers and how TCP ensures reliable delivery by sequencing and acknowledging packets. They will trace packet paths, diagnose transmission issues, and justify solutions using evidence from simulations and captures.

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Watch Out for These Misconceptions

• During Card Sort: Packet Transmission, watch for students assuming packets follow fixed routes.

  During Card Sort: Packet Transmission, have students send packets multiple times and note changing paths in the sequence labels, reinforcing that IP routes packets dynamically based on network conditions.

• During Packet Tracer: Network Build, watch for students believing data travels as a single continuous stream.

  During Packet Tracer: Network Build, ask students to send a large file and observe how the network divides it into smaller labeled packets before reassembly at the destination.

• During Wireshark: Traffic Capture, watch for students attributing ordering and reliability to IP alone.

  During Wireshark: Traffic Capture, pause the capture after a retransmission and ask students to locate the TCP acknowledgment numbers to see how TCP handles ordering and loss, not IP.

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Methods used in this brief

• Simulation Game
• Role Play