Explaining how data arrives intact across a network

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Date:

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Quick Questions

Shade in the A or B circle for each question.

1. Which explanation puts the steps of sending data in the correct order?

A Split into numbered packets, send, check for errors, resend if needed, reassemble

B Send, reassemble, split into packets, check for errors, resend if needed

2. Which sentence links two steps correctly using 'because'?

A Packets are numbered because the receiver needs to put them back in the right order.

B Packets are numbered because it makes the Wi-Fi signal stronger.

3. Why does the receiver check packets for errors?

A Because interference can lose, add or change data on the way

B Because packets always arrive broken and must be rebuilt

4. A packet fails its check at the receiver. What happens next in a full explanation?

A The packet is thrown away and the file is rebuilt with a gap

B The packet is resent so the data can still arrive complete and correct

5. Which answer uses the correct technical term for the pieces that data is split into?

A Blocks of Wi-Fi

B Packets

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1packets = split(data)		Areassemble(sort(packets, by=number))
2if error: resend(packet)		BA packet is resent even though the check passed. Resending should happen only when the check finds an error.
3Packets may arrive out of order, so the receiver uses the packet numbers to put them back in order.		CData is split into small numbered packets first, so each piece can be sent and tracked on its own.
4The receiver checks the data because interference may have changed it, and asks for a resend if the check fails.		DThe steps are in the wrong order. Data must be split into packets before it can be sent and reassembled at the end.
5reassemble(packets) split(data)		Eif check(data) == FAIL: request_resend()
6if check == OK: resend(packet)		FIf the check finds an error, the packet is sent again so the data still arrives complete and correct.

Definitions

split, send, check, resend, reassemble

Fill in the Blanks

Complete each line of code by filling in the missing parts.

_____, send, check, resend, reassemble

split, send, check, ______, reassemble

Data is split into numbered _______

Packets are checked because errors can happen when ____________ hits the signal

Packets are reassembled in order using their _______ so the file is complete

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A split data into packets

B number every packet

C send packets over the link

D skip checking for errors

E resend any packet with errors

Question 2

A split message into packets

B number each packet

C send packets, no link needed

D check packets for errors

Question 3

A receive all the packets

B put packets in random order

C join them into the file

Question 4

A if packet has no error:

B ask sender to resend it

C else:

D keep the packet

Question 5

A send packet 1

B do not wait for a reply

C if timeout: resend packet 1

Answer Key

Explaining how data arrives intact across a network

Section A: Quick Questions

A — Split into numbered packets, send, check for errors, resend if needed, reassemble

A — Packets are numbered because the receiver needs to put them back in the right order.

A — Because interference can lose, add or change data on the way

B — The packet is resent so the data can still arrive complete and correct

B — Packets

Section B: Match the Pairs

packets = split(data) → Data is split into small numbered packets first, so each piece can be sent and tracked on its own.

if error: resend(packet) → If the check finds an error, the packet is sent again so the data still arrives complete and correct.

Packets may arrive out of order, so the receiver uses the packet numbers to put them back in order. → reassemble(sort(packets, by=number))

The receiver checks the data because interference may have changed it, and asks for a resend if the check fails. → if check(data) == FAIL: request_resend()

reassemble(packets) split(data) → The steps are in the wrong order. Data must be split into packets before it can be sent and reassembled at the end.

if check == OK: resend(packet) → A packet is resent even though the check passed. Resending should happen only when the check finds an error.

Section C: Definitions

split, send, check, resend, reassemble — Data is split into numbered packets, sent over wired or wireless links, checked for errors, resent if needed, then reassembled in order so it arrives complete and correct.

Section D: Fill in the Blanks

split, send, check, resend, reassemble

Data is split into numbered packets

Packets are checked because errors can
happen when interference hits the signal

Packets are reassembled in order using
their numbers so the file is complete

Section E: Spot the Error

D — The check step is missing. Packets must be checked for errors so bad ones can be resent. The line should be 'check packets for errors'.

C — Packets cannot travel without a link. They are sent over a wired or wireless link such as a cable or Wi-Fi. The line should be 'send packets over a link'.

B — Packets must be put back in number order, because the numbers show where each piece belongs. Random order would scramble the file.

A — The condition is reversed. A resend should be requested only when the packet HAS an error. The line should be 'if packet has an error:'.

B — The sender must wait for an acknowledgement. If none arrives before the timeout, it knows to resend. Without waiting, the resend logic makes no sense.