Interactive end-of-chapter exercises


Supplement to Computer Networking: A Top Down Approach 8th Edition


"Tell me and I forget. Show me and I remember. Involve me and I understand." Chinese proverb

Textbook Cover

4G Wireless Tunneling

In the graphic below, a mobile phone has a TCP connection with the streaming server using wireless 4G. Assume that both the mobile phone and the server use TCP port 6146 and any intermediary nodes that tunnel the datagrams use port 5700.



Question List


1. What is the source IP address of the datagram sent from the mobile phone to the base station?

2. What is the destination IP address of the datagram sent from the mobile phone to the base station?

3. What is the transport-layer port number in the datagram sent from the mobile phone to the base station?

4. What transport-layer protocol is indicated in the datagram sent from the mobile phone to the base station?

5. Is there an encapsulated datagram within the datagram sent from the mobile phone to the base station? Answer Yes or No

6. What is the source IP address of the datagram sent from the base station to the serving gateway?

7. What is the destination IP address of the datagram sent from the base station to the serving gateway?

8. What is the transport-layer port number in the datagram sent from the base station to the serving gateway?

9. What transport-layer protocol is indicated in the datagram sent from the base station to the serving gateway?

10. Is there an encapsulated datagram within the datagram sent from the base station to the serving gateway? Answer Yes or No

11. What is the source IP address of the encapsulated datagram?

12. What is the destination IP address of the encapsulated datagram?

13. What is the transport-layer port number in the encapsulated datagram?

14. What transport-layer protocol is indicated in the encapsulated datagram?

15. What is the source IP address of the datagram sent from the serving gateway to the PDN gateway?

16. What is the destination IP address of the datagram sent from the serving gateway to the PDN gateway?

17. What is the transport-layer port number in the datagram sent from the serving gateway to the PDN gateway?

18. What transport-layer protocol is indicated in the datagram sent from the serving gateway to the PDN gateway?

19. Is there an encapsulated datagram within the datagram sent from the serving gateway to the PDN gateway? Answer Yes or No

20. What is the source IP address of the encapsulated datagram?

21. What is the destination IP address of the encapsulated datagram?

22. What is the transport-layer port number in the encapsulated datagram?

23. What transport-layer protocol is indicated in the encapsulated datagram?

24. What is the source IP address of the datagram sent from the PDN gateway to the server?

25. What is the destination IP address of the datagram sent from the PDN gateway to the server?

26. What is the transport-layer port number in the datagram sent from the PDN gateway to the server?

27. What transport-layer protocol is indicated in the datagram sent from the PDN gateway to the server?

28. Is there an encapsulated datagram within the datagram sent from the PDN gateway to the server? Answer Yes or No

29. Is data encrypted between the mobile phone and the base station? Answer Yes or No

30. Does the server know about any of the wireless tunneling? Answer Yes or No




Solution


1. From the mobile phone to the base station, the source address is 10.0.0.101

2. From the mobile phone to the base station, the destination address is 88.176.49.207

3. From the mobile phone to the base station, the port used is 6146

4. From the mobile phone to the base station, the protocol used is TCP

5. Is there an encapsulated datagram? No

6. From the base station to the serving gateway, the source address is 114.189.192.13

7. From the base station to the serving gateway, the destination address is 114.189.136.71

8. From the base station to the serving gateway, the port used is 5700

9. From the base station to the serving gateway, the protocol used is UDP

10. Is there an encapsulated datagram? Yes

11. The source address of the encapsulated datagram is 10.0.0.101

12. The destination address of the encapsulated datagram is 88.176.49.207

13. The port used in the encapsulated datagram is 6146

14. The protocol used in the encapsulated datagram is TCP

15. From the serving gateway to the PDN gateway, the source address is 114.189.136.71

16. From the serving gateway to the PDN gateway, the destination address is 204.237.195.13

17. From the serving gateway to the PDN gateway, the port used is 5700

18. From the serving gateway to the PDN gateway, the protocol used is UDP

19. Is there an encapsulated datagram? Yes

20. The source address of the encapsulated datagram is 10.0.0.101

21. The destination address of the encapsulated datagram is 88.176.49.207

22. The port used by the encapsulated datagram is TCP

23. The protocol used by the encapsulated datagram is 10.0.0.101

24. From the PDN gateway to the server, the source address is 10.0.0.101

25. From the PDN gateway to the server, the destination address is 88.176.49.207

26. From the PDN gateway to the server, the port used is 6146

27. From the PDN gateway to the server, the protocol used is TCP

28. Is there an encapsulated datagram? No

29. Yes, the base station and mobile phone encrypt data between them

30. No, the server is blissfully unaware of the wireless infrastructure or tunneling



That's incorrect

That's correct

The answer was: 10.0.0.101

Question 1 of 30

The answer was: 88.176.49.207

Question 2 of 30

The answer was: 6146

Question 3 of 30

The answer was: TCP

Question 4 of 30

The answer was: No

Question 5 of 30

The answer was: 114.189.192.13

Question 6 of 30

The answer was: 114.189.136.71

Question 7 of 30

The answer was: 5700

Question 8 of 30

The answer was: UDP

Question 9 of 30

The answer was: Yes

Question 10 of 30

The answer was: 10.0.0.101

Question 11 of 30

The answer was: 88.176.49.207

Question 12 of 30

The answer was: 6146

Question 13 of 30

The answer was: TCP

Question 14 of 30

The answer was: 114.189.136.71

Question 15 of 30

The answer was: 204.237.195.13

Question 16 of 30

The answer was: 5700

Question 17 of 30

The answer was: UDP

Question 18 of 30

The answer was: Yes

Question 19 of 30

The answer was: 10.0.0.101

Question 20 of 30

The answer was: 88.176.49.207

Question 21 of 30

The answer was: 6146

Question 22 of 30

The answer was: TCP

Question 23 of 30

The answer was: 10.0.0.101

Question 24 of 30

The answer was: 88.176.49.207

Question 25 of 30

The answer was: 6146

Question 26 of 30

The answer was: TCP

Question 27 of 30

The answer was: No

Question 28 of 30

The answer was: Yes

Question 29 of 30

The answer was: No

Question 30 of 30

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