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