📡 What is a Protocol?
A Protocol is a standard set of rules that govern how data is transmitted across a network. Without them, devices from different manufacturers could not communicate.
Key Term: Interoperability
The ability of computer systems or software to exchange and make use of information.
📧 The Email Triangle
The 4-Layer TCP/IP Model
1. Application Layer
Where the network applications operate (Browsers, Email clients). Encodes the data being sent.
2. Transport Layer
Sets up communication between hosts. Splits data into packets and handles error checking.
3. Internet Layer
Addresses and packages data for transmission. Routes packets across different networks using IP addresses.
4. Link Layer
The physical connection. Handles hardware interaction (MAC addresses, Ethernet cables, Wi-Fi radio waves).
Activity 1: The Data Packet’s Journey
Trace an HTTP request from your browser to a web server.
You type a URL into the browser. Which protocol is used?
A header is added to the packet. What specific address is added here?
" Encapsulation is like putting a letter inside an envelope, then inside a crate, then inside a shipping container.
Activity 2: Layer Mapping
Drag the protocols into their theoretical layers:
Application
Transport
Internet
Link
Network Speed Calculations
Construct the expressions for the following scenarios:
1. A file is 500MB. The network speed is 50Mbps. Calculate the time in seconds.
2. Rearrange the formula to find the File Size if you know Time and Rate.
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