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Year 7 · Autumn 2 · Networks

Semaphore and Morse: what a protocol is

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What this lesson covers

Topic 15 Networks and the internet

KS3 Computing · A network is computers joined up to share. The internet is a network of networks. Data crosses it in small numbered packets, following agreed rules called protocols.

Networks and Digital CommunicationCambridge Lower Secondary Computing 0860

You will learn to

  • Explain what a protocol is: rules that both sides agree before they communicate.
  • Use a simple code, like Morse, to send a word across the room.
  • Identify why a message fails when the two sides follow different rules.

Success criteria

  • I can send and receive a short word using the class's agreed code.
  • I can say what went wrong when our first try failed.
  • I can explain the word 'protocol' in one sentence.

Key words

Say each word, then read what it means. Every one is in the glossary too.

protocol
A set of agreed rules for communication.
LAN / WAN
Local Area Network: a network over a small area.
Router
Connects different networks and forwards packets.
IP address
A device's address on a network. IPv4 = 4 bytes.
MAC address
Fixed unique ID of a network card. 48 bits in hex.
DNS
Domain Name System: turns website names into IP addresses.
Packet
A small numbered chunk of data sent across a network.
Bandwidth / latency
How much data a connection can carry per second.

The explanation

Read it here, or open the study page below to go one step at a time with things to try.

Protocols

A protocol is a set of agreed rules for communicating.

ProtocolJob
TCPSplits into packets, numbers them, checks they all arrive
IPAddresses and routes packets
HTTP / HTTPSFetches web pages (HTTPS is encrypted)
DNSTurns names into IP addresses
SMTPSends email
IMAP / POPCollects email
FTPTransfers files
★Remember

Protocols work in layers, each with one job. Wi-Fi or cable, the web page doesn't care.

Study it

Open the study page and go one step at a time.

Topic 15 · Year 7

Networks and the internet

A network is computers connected to share data. The internet is a network of networks. Data travels in small packets, following rules called protocols.

Check yourself

One question at a time. The reason shows after each answer.

Saved on this device.