OSI & TCP/IP Models Cheat Diagram: Memory Tricks

1. OSI Model (7 layers)

• Mnemonic (top → bottom): All People Seem To Need Data Processing → Application, Presentation, Session, Transport, Network, Data Link, Physical
• PDU association:
  
  • Layers 7–5 → Data
  • Layer 4 → Segment
  • Layer 3 → Packet
  • Layer 2 → Frame
  • Layer 1 → Bits
  
  

 2. TCP/IP Model (4 layers)

• Mnemonic (top → bottom): All Teachers Instruct Novices → Application, Transport, Internet, Network Access
• Quick link to OSI:
  
  • Application ↔ Application/Presentation/Session
  • Transport ↔ Transport
  • Internet ↔ Network
  • Network Access ↔ Data Link + Physical
  
  

 3. Special Questions

• Binary Transmission (OSI): Layer 1 → Physical
• Hardware/Media (TCP/IP): Network Access Layer