Follow a Message through a Router
Trace the connected links from the sender to the named destination.
About 18 minutes, plus any extended practice
Open lesson 1Messages Travel through a Network
Using route A-R-B, send a three-part paper word with arrivals 3,1,2. Show restoration by number and explain what an absent acknowledgment can and cannot prove.
Before you begin
- Follow labeled paths and order small whole numbers.
Choose by skill rather than age alone. Read with an adult when useful, revisit a lesson, or explore another grade.
Follow the lesson sequence
Reassemble Numbered Message Parts
Order packet contents by their supplied sequence numbers, not by arrival order.
About 18 minutes, plus any extended practice
Open lesson 2Distinguish a Web Page from Its Address
Match the requested resource to the address in the supplied lookup table.
About 18 minutes, plus any extended practice
Open lesson 3Use an Acknowledgment to Check Receipt
Use the explicit acknowledgment as receipt evidence and keep missing responses uncertain.
About 18 minutes, plus any extended practice
Open lesson 4Review and transfer
After the lessons, try 4 new review cases and a practical task. Each answer has an explanation and a link back to the related lesson.
Open the unit reviewGuest answers are temporary. Keep your own paper or document; this unit does not certify completion or record a school grade.
Topic references
- 2026 CSTA PK–12 Computer Science Standards: topic reference — Systems & Security
These references informed the topic selection. They do not certify complete standards alignment.