Layers and protocols 2025 RDU

Do Now:

1. What does HTTP stand for?

2. What's the difference between HTTP and HTTPS?

3. What happens when a message is sent from one person to another via Whatsapp?

​Think-Pair-Share

Networks
Protocols and TCP/IP Layers

​Mr Dukes

Lesson Objectives

• Define a network protocol is and state why it is important.

• Identify the four layers of the TCP/IP model.

• Describe what happens at each layer of the TCP/IP model.

• Match common protocols (e.g., HTTP, TCP, IP) to the correct layer.

​Protocol (noun)

​Protocol (noun)

​​The rules about what you must do and how you must behave in official or very formal situations.

​Protocol (noun)

​​The rules about what you must do and how you must behave in official or very formal situations.

​A set of rules that govern how data is transmitted between devices on a network.

Multiple Choice

Which of these is the correct definition of a protocol in Computer Science?

• A method for data encryption.
• A set of rules for communication between network devices.
• A type of software application.
• A hardware component for networking.

Why do we need protocols?

​Turn & Talk

​Student A: I think we need protocols for transmitting data because...

​Student B: I agree because.. / would like to build on that... / would like to challenge that because...

There are several Protocols you need to know

• Ethernet, Wi-Fi

• HTTP / HTTPS

• FTP

• SMTP

• IMAP

• POP

• TCP

• IP

FTP

File Transfer Protocol (FTP)

This is when a computer sends or retreives files from a remote server or computer.

E.g OneDrive, iCloud, etc..

Sends from client to server // sends from server to client

Multiple Choice

What does HTTP Stand for?

• Hyper Text Transfer Protocol

• Hyper Text Transmission Protocol

• High Text Transfer Protocol

• Hyper Tech Transfer Protocol

Multiple Choice

What protocol would be used to upload a photograph to the internet?

• HTTP

• HTTPS

• FTP

• ASAP

• RSVP

Multiple Choice

Which of the following is most likely to use HTTPS.

• Banking Website

• School Website

• Local Tourist Information Site

• Gaming site where you don't login

Multiple Choice

Which email protocol will be used when sending an email?

• SMTP

• POP

• IMAP

• IPA

• FTP

Open Ended

What is the difference between POP and IMAP?

TCP

Transmission Control Protocol (TCP)

This protocol is responsible for:

• Setting up communication between two hosts

• Breaking up messages sent over the Internet into small chunks called packets

• Reassembles the packets at the other end

• Detects errors

• Resends lost messages
  
  

IP

Internet Protocol (IP)

This is the set of rules that dictate how data should be delivered over the internet

• Addresses and packages data for transmissions.

• Routes packets across the network

Multiple Choice

When data is sent over the internet it is broken up into...

• Packets

• Blocks

• Binary

• Boxes

Multiple Choice

What does TCP stand for?

• Transfer Control Protocol

• Transmission Control Protocol

• Transfer Character Protocol

• Transmission Character Protocol

Independent practice


Teams > Activity 1: Protocols

Answers

TCP/IP Layer Model

This layer model has 4 layers where different protocols operate to pass data across a network.

The four layers are:

1. - Application

2. - Transport

3. - Internet

4. - Link

Why layers are used

• Divides the complex task of networking into smaller, simpler tasks that work with each other.

• A layer can be removed/changed etc. …without affecting any other layers

• Each layer has its own purpose so it does not need to consider what the other layers do …so it can be programming individually

• Different layers can interface with different hardware from different vendors

​Which protocols would be used in each layer?

​Which protocols would be used in each layer?

​HTTP, HTTPS, FTP, SMTP, IMAP, POP3

​Which protocols would be used in each layer?

TCP

​HTTP, HTTPS, FTP, SMTP, IMAP, POP3

​Which protocols would be used in each layer?

IP

​HTTP, HTTPS, FTP, SMTP, IMAP, POP3

TCP

​Which protocols would be used in each layer?

Wi-Fi, Ethernet

​HTTP, HTTPS, FTP, SMTP, IMAP, POP3

TCP

IP

Multiple Choice

What are the advantages of layering?

• Modularity, separation of concerns, and reusability.
• Reduced performance and efficiency
• Higher maintenance costs
• Limited flexibility and adaptability
• Increased complexity and confusion

Match

Match the layer with the typical protocols used

• Application

• Transport

• Internet

• Link

HTTP, HTTPS, SMTP

TCP

IP

Ethernet, Wi-Fi

• HTTP, HTTPS, SMTP

• TCP

• IP

• Ethernet, Wi-Fi

Open Ended

The TCP/IP model uses layers including the application layer and transport layer.

Explain why the TCP/IP model uses layers.

Teams > Activity 2

Today we have:

• Defined a network protocol is and state why it is important.

• Identified the four layers of the TCP/IP model.

• Described what happens at each layer of the TCP/IP model.

• Matched common protocols (e.g., HTTP, TCP, IP) to the correct layer.