What is IoT

• Not “a computer connected to the internet”
  • Then it is really just another computer connected to the internet
• Must be something else
  • It is simply devices that are resource constrained
    • Usually in more than one way
• Autonomous operation, the connection might not be permanent

What differentiates a computer from an IoT device?

• Constrained in (one or more of):
  • Memory
  • CPU
  • Network bandwidth and/or latency
  • Storage

What is the internet again?

OSI model

1. Physical Layer
2. Data Link Layer
3. Network Layer
4. Transport Layer
5. Session Layer
6. Presentation Layer
7. Application Layer

• Wikipedia: OSI model
• Wikipedia: OSI model#Examples

Layer 1: Physical Layer

• 10BASE5, 10BASE2
• 10BASE-T / 100BASE-TX / 1000BASE-TX
• 802.11a/b/g/n PHY
• RS-232

Layer 2: Data Link Layer

• Ethernet
• WiFi
• Bluetooth
• Token Ring

Layer 3: Network Layer

• IP
• ICMP
• IPX

Layer 4: Transport Layer

• TCP
• UDP

Layer 5: Session Layer

• “sockets”
• NetBIOS

Layer 6: Presentation Layer

• SSL

Layer 7: Application Layer

• HTTP
• DNS
• (everything else..)
• MQTT

Assignments

• Measure round trip time/latency. Measure UDP, TCP. Measure when the packet size is greater than the MTU