Review Questions:
Chapter 6
1. What is a base station? What it is used for? What is handoff?
2. Why communications across wireless links are more difficult?
3. Describe the major characteristics of an ad hoc network
4. Define the Hidden Terminal Problem and the Exposed Terminal Problem
5. What are the two Wireless LAN architectures? ‘
6. What are the multiple access protocols for 802.11b/g/a?
7. Why it is difficult to implement collision detection in 802.11 wireless network?
8. Explain the four-way handshake protocol (RTS-CTS-DATA-ACK) in 802.11b
9. Explain how carrier sense is done at two levels in 802.11 MAC layer.
10. Explain the 802.11 CSMA/CA protocol.
11. Explain the backoff procedure in DCF of 802.11.
12. Is Access Point a physical layer device or a link layer device? How does it convert a
802.11 frame to a 802.3 Eithernet frame and vice versa?
13. Explain the following concepts: home network, home agent, visited network, foreign
agent, correspondent, permanent address, care-of-address (COA).
14. There are two approaches to handle mobility. Explain both of them. Which is more
applicable?
15. Explain mobility via indirect routing
16. Explain mobility via direct routing
17. What are the three components in Mobile IP standard?
18. How does a mobile register itself with its foreign agent and home agent in Mobile IP?
How does a mobile determine its home/foreign agent?
19. You carry your notebook computer from work to home. Do you use Mobile IP? If not,
which protocol do you use to connect to the Internet? In which condition Mobile IP
must be used?
20. Can TCP/UDP run over wireless? In TCP congestion control, a lost packet is assumed
to be caused by congestion in intermediate routers and therefore congestion window
size is decreased. While in wireless networks, a lost event results from lossy links. In
this case, how can we adjust the congestion window to improve the performance?
21. Review Questions at page 559
22. Homework questions 6.5 and 6.6
Chapter 5:
1. True or False: A packet is delivered from source to destination via multiple hops. All
the links from the source to the destination must operate the same link layer Protocol.
2. When reliable delivery between adjacent nodes is necessary when is not?
3. Why we say that a network adapter (interface card) is semi-autonomous?
4. Do you think error detection can be 100% reliable? Why and why not?
5. Why can the two-dimensional parity check correct single error?
6. How to compute the CRC checksum?
7. Understand the three classes of MAC protocols
8. How does slotted Aloha work? What is its efficiency (how to compute)?
9. How does the unslotted Aloha work? Why its efficiency is only 50% of slotted Aloha?
10. How does CSMA work? Why does collision still happen in CSMA?
11. How does CSMA/CD work? How collision is detected? Why CD is not workable in
wireless links? How much time in the worst case CD can take?
12. Why MAC addresses are needed?
13. How does ARP work? What is it for?
14. How does DHCP protocol work? What is it for?
15. Explain the Ethernet CSMA/CS algorithm
16. Why a jam signal is needed in the Ethernet CSMA/CD protocol?
17. Explain the Exponential backoff procedure in Ethernet CSMA/CD protocol
18. Explain the differences among hubs, switches, and routers
19. Explain the filtering and forwarding functions of a switch.
20. How a switch table is constructed? How traffic is isolated in a switch?
21. What is byte stuffing?
22. Review Questions at page 493-494
23. Homework Questions
Chapter 4:
1. What are the two functions of the network layer?
2. Transport layer can provide the connection-oriented service while the network layer
provides a connection service. What are the differences?
3. Why the virtual circuit number must be changed from link to link in a virtual circuit
network?
4. What are the major differences between a datagram network and a virtual circuit
network?
5. What is the longest prefix matching/
6. Understand the switching function of different switching fabrics in routers
7. Understand the relationship between input/output queuing and network congestion
8. How IP fragmentation and reassembly is done
9. IP address vs. subnet address. How to define a subnet
10. Explain the CIDR IP addressing mechanism
11. Why hierarchical addressing?
12. What is NAT? What it is for?
13. What is ICMP? What is it for?
14. Do you think IPv6 will finally succeed? Why and why not?
15. Understand all the three routing algorithms: link state, distance vector, and
hierarchical routing.
16. Review questions at pages 400-403
17. Homework questions