CSCI 233 Internet Protocols Class 2

1. CSCI 233Internet Protocols Class 2 David C. Roberts

2. Course Mechanics • 50 word limit on homework answers and exam answers • “Which is better?”--trick question!

3. Being an Adult • Show up on time for class • Homework in on time • Show up for the exam • 50 word limit on answers

4. Good Citizen Principle • In a crisis, when resources are short, we tend to hoard resources • The hoarding creates shortages • What if, in a crisis, each of us reduced our use of scarce resources? • The Internet operates on the Good Citizen Principle

5. Good Citizen Principle When a resource is scarce, instead of trying to claim as much of it as possible, reduce your use of that resource until the scarcity passes This is an important design principle for the Internet. We will see it again and again.

6. Outline • Review of networking technologies • Internetworking • Protocol Layering

7. Modern Ethernet

8. Ethernet Frame Header Payload

9. Internetworking • How to interconnect networks? • Application level • Network Level • Users attach to a local network • Internetworking software hides details of networks, forwards information among them

10. Internet Architecture

11. Internet Architecture

12. The User’s View

13. Protocol Layering • Internet protocols are organized into levels • Each level deals with certain topics • Levels make protocols easier to understand

14. Just Think of Problems • Hardware failure • Network congestion • Packet loss • Data corruption • Data duplication • Data arriving out of sequence

15. Layers

16. TCP-IP 5-Layer Reference Model

17. In Reality

18. How It Works

19. On The Internet

20. Important Boundaries

21. IP Demultiplexing