EJERCICIOS DEL LIBRO:
TCP/IP Protocol Suite.
Behrouz A. Forouzan.
ISBN 0-256-24166-X
1ra edición.
CHAPTER 11 - PRACTICE SET (11.8 Section)
Multiple choice.
1. UDP is a acronym for _________.
a. User Delivery Protocol.
b. User Datagram Procedure.
c. User Datagram Protocol.
d. Unreliable Datagram Protocol.
2. In the sending computer, UDP receives a data unit from the _________ layer.
a. application.
b. transport.
c. IP
d. data link.
3. In the sending computer, UDP sends a data unit to the _________ layer.
a. application.
b. transport.
c. IP
d. data link.
4. UDP and TCP are both __________ layer protocols.
a. physical.
b. data link
c. network
d. transport.
5. Which of the following functions does UDP perform?
a. process-to-process communication.
b. host-to-host communication.
c. end-to-end reliable data delivery.
d. all of the above.
6. When the IP layer of a receiving host receives a datagram, _________.
a. delivery is complete.
b. a transport layer protocol takes over.
c. a header is added.
d. b and c.
7. UDP needs the _____ address to deliver the user datagram to the correct application program.
a. port.
b. application.
c. Internet
d. physical.
8. Which is a legal port address?
a. 0
b. 513
c. 65,535
d. all of the above.
9. The definition of reliable delivery includes ____________.
a. error-free delivery.
b. receipt of the complete message.
c. in-order delivery
d. all of the above.
10. Which of the following does UDP guarantee?
a. nonduplication of data.
b. in-order delivey
c. error-free delivery
d. a and b.
11. Which of the following does UDP guarantee?
a. sequence numbers on each user datagram
b. acknowledgments to the sender.
c. flow control
d. none of the above.
12. Because there is no_________, UDP is considered a connectionless transport protocol.
a. acknowledgment.
b. virtual circuit.
c. reliability.
d. data flow control.
13. The source port address on the UDP user datagram header defines __________ .
a. the sending computer
b. the receiving computer.
c. the application program of the sending computer.
d. the application program of the receiving computer.
14. Which of the following is not part of the UDP user datagram header?
a. length of header.
b. source port address.
c. checksum.
d. destination port adress.
15. The __________ defines the client program.
a. ephemeral port number.
b. IP address.
c. well-know port number.
d. physical address.
16. The _________ defines the server program.
a. ephemeral port number.
b. IP address.
c. well-know port number.
d. physical address.
17. If the outgoing queue of a UDP client overflows, _________ .
a. the user datagrams are discarded and a port unreachable message is sent.
b. the operating system asks the server to wait before any more messages are sent.
c. new queues are initiated.
d. the operating system asks the client process to wait before any more messages are sent.
18. If the incoming queue of a UDP client overflows, _________ .
a. the user datagrams are discarded and a port unreachable message is sent.
b. the operating system asks the server to wait before any more messages are sent.
c. new queues are initiated.
d. the operating system asks the client process to wait before any more messages are sent.
19. If the incoming queue of a UDP server overflows, _________ .
a. the user datagrams are discarded and a port unreachable message is sent.
b. the operating system asks the server to wait before any more messages are sent.
c. new queues are initiated.
d. the operating system asks the client process to wait before any more messages are sent.
20. Which component in our UDP package allocates the queues?
a. control-block module.
b. control-block table.
c. input module.
d. output module.
21. Which component in our UDP package communicates with the ICMP software package?
a. control-block module.
b. control-block table.
c. input module.
d. output module.
22. Which component in our UDP package sends user datagrams to the IP layer?
a. control-block module.
b. control-block table.
c. input module.
d. output module.
23. Which column in the control-block table contains information from the UDP header?
a. state.
b. process ID.
c. port number.
d. queue number.
Exercises.
24. In cases where reliability is not of primary importante, UDP World make a good transport
protocol. Give examples of specific cases.
26. Do port address need to be unique? Why or why not? Why are port addresses shorter than IP
addresses?
28. Show the entries for the header of a UDP user datagram that carries a message from a TFTP
client to a TFTP server. Fill the checksum field with 0s. Choose an appropriate ephemeral port
number and the correct well-know port number. The length of data is 40 bytes.
29. Show the entries for the header of a UDP user datagram that carries a message from a FTP
client to a FTP server. Fill the checksum field with 0s. Choose an appropriate ephemeral port
number and the correct well-know port number. The length of data is 20 bytes.
30. Calculate the checksum for the following binary numbers. Give the result in binary. Use the
16-bit format.
11000111 11100001
10000111 10001001
11100101 10100011
11111111 11100111
32. Calculate the checksum for the following hexadecimal numbers. Give the result in
hexadecimal. Use the 16 bit format.
3478 A233 1234 8976
33. A client with IP 122.45.12.7 sends a message to snmp server with IP 200.112.45.90. Show
the client and server socket addresses.
34. A client with IP 14.90.90.33 sends a message to tftp server with IP 130.45.12.7. Show the
client and server socket addresses.
43. The entries for a header of UDP are: 0632000D001C000016. Show:
a) source port.
b) destination port.
c) total length.
d) data length.
e) is the message sends from client to server or server to client?
f) what is the process?