Answer the following question

1. What are two reasons errors may occur at the data link layer?
2. Why is parity checking not the best technique error detection?
3. Explain how CRC works at the data link layer.
4. What responsibilities does the NIC have on both the sending and receiving end of data communication?
5. There are three broad classes that deal with multiple access; channel partitioning, random access and taking turns. Define each and discuss a networking structure that might be most appropriate for each class.
6. How is the jam signal used in CSMA/CD?
7. Explain what type of data each section of the Ethernet frame structure below contains.
8. Explain the difference between wireless and mobility. Is it possible for a devise to be wireless but have limited mobility? Give an example.
9. What are the primary differences between the 802.11 architectures of a, b, g, and n?
10. How does a wireless device typically detect a wireless network?
11. In mobility management, routing and indirect routing to mobile node becomes a more complex task with the use of foreign agents, care-of-addresses, visited addresses, and permanent addresses. Explain how mobility may be accomplished using these techniques.
12. Describe at least two methods for audio and video compression. Why is compression needed?
13. Explain how intrusion detection systems work in general. Do you feel this is an area of computer science that can ever be perfected?
14. Describe how RSA encryption works.
15. What is one method that can be used to ensure message integrity?
16. What risks do intruders pose to systems?
17. Explain why encryption techniques such as Caesar Cipher and Monoalphabetic ciphers are not very effective against intruders.
18. What is one method that can be used to ensure that an individual is who they say they are when communicating with them remotely.
19. What role does the Certification Authority play online?
20. Describe how the man-in-the-middle attack works and why it is so difficult to detect. Also describe how this attack may be prevented, if is possible.
21. List at least five tasks performed under the umbrella of network management.

PROBLEMS:
22. Parity checking is one method of error detection, based on the following bit pattern, what would be the bit added on to the bit pattern if even parity is used.
0111011100111001 ____

23. Two dimensional bit parity is another method of error detection. Based on the following bit patters what would be the results if even parity is used.
0 1 0 1 1 0 1 1 ___
1 1 0 1 0 0 0 0 ___
1 1 0 0 1 0 0 1 ___