2. ICC Module 3 Lesson 4 – Networking 1 / 16 © 2015 Ph. Janson Information, Computing & Communication Networking – Clip 3 – Protocol encapsulation School of Computer Science & Communications Ph. Janson, W. Zwaenepoel

3. ICC Module 3 Lesson 4 – Networking 2 / 16 © 2015 Ph. Janson Outline ►Computer communication basics  Clip 1 – Protocols & messages Clip 1  Clip 2 – Protocol layers Clip 2  Clip 3 – Protocol encapsulation Clip 3  Clip 4 – Switching Clip 4 ►Internet basics  Clip 5 – Internet topology & interfaces Clip 5  Clip 6 – Internet addressing & routing Clip 6  Clip 7 – Internet route calculation Clip 7  Clip 8 – Internet protocols Clip 8 ►Computer network paradigms  Clip 9 – Network paradigms Clip 9 Intro clipPrevious clipNext clip

4. ICC Module 3 Lesson 4 – Networking 3 / 16 © 2015 Ph. Janson Encapsulation = embedding / nesting of protocols ►Each protocol in its own layer ►Each protocol with its own header Upon sending: protocol encapsulation ►Protocol layer N:  Takes messages coming from layer N+1 (incl. headers of layers N+1, N+2, …)  Tacks its own layer N protocol header in front of them  And Passes the resulting messages to layer N-1 if N>1 Or transmits them to the network if N=1

5. ICC Module 3 Lesson 4 – Networking 4 / 16 © 2015 Ph. Janson Encapsulation on the sending side Program Application Transport Network Link Physical data

6. ICC Module 3 Lesson 4 – Networking 5 / 16 © 2015 Ph. Janson Encapsulation on the sending side data h5h5 h5h5 Program Application Transport Network Link Physical

7. ICC Module 3 Lesson 4 – Networking 6 / 16 © 2015 Ph. Janson Encapsulation on the sending side data h5h5 h5h5 h5h5 h5h5 h4h4 h4h4 Program Application Transport Network Link Physical

8. ICC Module 3 Lesson 4 – Networking 7 / 16 © 2015 Ph. Janson Encapsulation on the sending side data h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h4h4 h4h4 h4h4 h4h4 h3h3 h3h3 Program Application Transport Network Link Physical

9. ICC Module 3 Lesson 4 – Networking 8 / 16 © 2015 Ph. Janson Encapsulation on the sending side data h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h4h4 h4h4 h4h4 h4h4 h4h4 h4h4 h3h3 h3h3 h3h3 h3h3 h2h2 h2h2 Program Application Transport Network Link Physical

10. ICC Module 3 Lesson 4 – Networking 9 / 16 © 2015 Ph. Janson Encapsulation on the sending side data h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h4h4 h4h4 h4h4 h4h4 h4h4 h4h4 h4h4 h4h4 h3h3 h3h3 h3h3 h3h3 h3h3 h3h3 h2h2 h2h2 h2h2 h2h2 h1h1 h1h1 Program Application Transport Network Link Physical

11. ICC Module 3 Lesson 4 – Networking 10 / 16 © 2015 Ph. Janson Encapsulation = embedding / nesting of protocols ►Each protocol in its own layer ►Each protocol with its own header Upon receiving: protocol “de”capsulation ►Protocol layer N:  Receives messages From the network if N=1 From layer N-1 if N>1  Interprets and removes its own layer N protocol header  And passes the resulting messages to layer N+1 (incl. headers for layers N+1, N+2, …)

12. ICC Module 3 Lesson 4 – Networking 11 / 16 © 2015 Ph. Janson “De”capsulation on the receiving side data h5h5 h5h5 h4h4 h4h4 h3h3 h3h3 h2h2 h2h2 h1h1 h1h1 Program Application Transport Network Link Physical

13. ICC Module 3 Lesson 4 – Networking 12 / 16 © 2015 Ph. Janson “De”capsulation on the receiving side data h5h5 h5h5 h5h5 h5h5 h4h4 h4h4 h4h4 h4h4 h3h3 h3h3 h3h3 h3h3 h2h2 h2h2 h2h2 h2h2 h1h1 h1h1 Program Application Transport Network Link Physical

14. ICC Module 3 Lesson 4 – Networking 13 / 16 © 2015 Ph. Janson “De”capsulation on the receiving side data h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h4h4 h4h4 h4h4 h4h4 h4h4 h4h4 h3h3 h3h3 h3h3 h3h3 h3h3 h3h3 h2h2 h2h2 h2h2 h2h2 h1h1 h1h1 Program Application Transport Network Link Physical

15. ICC Module 3 Lesson 4 – Networking 14 / 16 © 2015 Ph. Janson “De”capsulation on the receiving side data h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h4h4 h4h4 h4h4 h4h4 h4h4 h4h4 h4h4 h4h4 h3h3 h3h3 h3h3 h3h3 h3h3 h3h3 h2h2 h2h2 h2h2 h2h2 h1h1 h1h1 Program Application Transport Network Link Physical

16. ICC Module 3 Lesson 4 – Networking 15 / 16 © 2015 Ph. Janson “De”capsulation on the receiving side data h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h4h4 h4h4 h4h4 h4h4 h4h4 h4h4 h4h4 h4h4 h3h3 h3h3 h3h3 h3h3 h3h3 h3h3 h2h2 h2h2 h2h2 h2h2 h1h1 h1h1 Program Application Transport Network Link Physical

17. ICC Module 3 Lesson 4 – Networking 16 / 16 © 2015 Ph. Janson “De”capsulation on the receiving side data h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h5h5 h4h4 h4h4 h4h4 h4h4 h4h4 h4h4 h4h4 h4h4 h3h3 h3h3 h3h3 h3h3 h3h3 h3h3 h2h2 h2h2 h2h2 h2h2 h1h1 h1h1 Program Application Transport Network Link Physical