OSI Model (Open Systems Interconnection Model)

Overview

The OSI Model is a conceptual framework used to understand network interactions in seven distinct layers. Each layer serves a specific function in data transmission between systems.

Table of Contents

• Layer Overview
• Detailed Layer Description
• Common Protocols
• Real-World Examples
• Troubleshooting Using OSI Model

Layer Overview

1. Application Layer
   • End-user interaction with network applications
   • Examples: HTTP, FTP, SMTP, DNS
2. Presentation Layer
   • Data translation and encryption
   • Examples: SSL/TLS, JPEG, ASCII
3. Session Layer
   • Managing connections between applications
   • Examples: NetBIOS, RPC
4. Transport Layer
   • End-to-end communication and data flow
   • Examples: TCP, UDP
5. Network Layer
   • Routing and logical addressing
   • Examples: IP, ICMP, OSPF
6. Data Link Layer
   • Physical addressing and local network access
   • Examples: Ethernet, WiFi, MAC addressing
7. Physical Layer
   • Raw bit transmission over physical medium
   • Examples: Cables, Radio waves, Fiber optics

Detailed Layer Description

7. Application Layer