OSI Introduction

Open Systems Interconnection Model

• Known as OSI model
• Created by International Organization for Standardization (ISO, yes it doesn't line up)
• Seven layers
• Conceptual model

OSI Model

• Physical
• Data-Link
• Networking
• Transport
• Session
• Presentation
• Application
• (Please Do Not Touch Steve's Pet Alligator)

OSI Model vs. Reality

• Ethernet/Wi-Fi = Layers 1 and 2
• TCP/IP = Layers 3 and 4
• HTTP/HTTPS = Layers 4 and 5
• HTML/PDF = Layer 6 and maybe 7