Chapter 1
Network Architecture
Section 1.1
The 7-Layer OSI Model
How computers standardize communication across global networks.
Concept
What is the OSI Model?
The OSI (Open Systems Interconnection) model breaks network communication down into 7 layers. Data travels down from layer 7 (Application) on the sending device and
Visual Diagram
OSI Layer Breakdown
Chapter 2
Packet Routing Visualizer
Section 2.1
Interactive Packet Simulation
Watch a data packet hop from router to router to reach its destination server.
Interactive Graph
Live Packet Journey
Data packets are routed hop by hop using routing tables. If a node fails or becomes congested,
Chapter 3
IP Addresses & Headers
Section 3.1
Anatomy of an IPv4 Packet
Every packet contains control metadata (headers) and useful data (payload).
Structure
IPv4 Header Layout
A standard IP header contains essential routing information:
Concept
Key Concepts
- Source IP: Address of the device generating the request.
- Destination IP: Address of the target server (e.g. 192.0.2.1).
- TTL (Time to Live): Prevents packets from looping forever by decrementing at each hop.
Interactive Practice
Test your knowledge
Demo Quiz
Question 1: Which layer handles IP routing?
Select the layer responsible for path determination and logical addressing.
Correct answer: Layer 3 (Network Layer)
Routers operate at layer 3 to route IP packets across different networks.
★ Key Points
Demo Summary
OSI Layers: Modular model dividing network tasks into 7 distinct layers.
Packets: Data units encapsulated with control headers (Source IP, Destination IP, TTL).
Routing: Routers forward packets hop by hop toward their final destination.