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Inside the Machine G3 to G5 / Week 08 / Friday
5/6
Week 08 · Networks and the internet

Friday

A video call's journey
// How a message leaves the device and finds its way
⏱ about 15 min

Friday: A video call's journey

Friday review day. A neighbor wants to video call her grandfather in another country. "How can my face reach him so fast?" she wonders aloud.

Rocket is ready. "Packets! Addresses! Hops!" Raven laughs. "What do you notice? You remembered the whole week."

Nova draws a glowing path from the tablet to the sky. "Let us walk it step by step, together."

The whole path

A video call is a flood of packets. The camera takes many pictures a second. Each picture is cut into packets.

The packets carry the grandfather's device address. They go by Wi-Fi to the router, then hop across the internet.

His device sorts them by number and rebuilds the pictures. His packets travel back the same way. All of this happens in a blink.

Camera takes a picture
↓
Cut into numbered packets with an address
↓
Wi-Fi radio to the home router
↓
Hops from router to router
↓
Grandfather's device sorts by number
↓
His screen shows the picture
ORDER THE VIDEO CALL
  • Tap a card.
  • Then tap its spot.
1First
2Second
3Third
4Fourth
5Last

Week 8 check

NETWORK WORDS
  • Read the question.
  • Tap your answer.
Devices connected to share information are called a what?
What does Wi-Fi use to carry signals?
Which device is the mail room of the home network?
A small piece of a message with an address and a number is a what?
StatementTrue or false?
Walls and distance weaken a Wi-Fi signal.?
Packets must all take the same path.?
Each packet has a number so it can be put back in order.?
Networks send packets to number addresses.?
WHY THIS EXERCISEThese are the facts that explain almost every network problem you will meet.

Fix-It Bay cases

Read each case. Use what you learned to pick what the crew should say.

WHAT SHOULD THE CREW SAY?
  • Read the question.
  • Tap your answer.
A video call keeps freezing in the far bedroom.
A neighbor asks why a photo arrived in pieces and then became whole.
A tablet cannot join the Wi-Fi and asks for the network password.
What does each router read to decide where to send a packet?
What is one step from one router to the next called?
If a packet goes missing, what does the receiver do?
What is the biggest network, the one that joins networks all over the world?
WHY THIS EXERCISEThe internet is a network of networks. Your home network is one tiny part of it.
Try it
Tell a grown-up how your face reaches a friend on a video call.
Use the words packet, router, address and hop.

Week 8 is done, Crew Technician! You can follow a message from a tablet to the other side of the world. Next week you learn the method the crew uses to fix anything.

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