Homework #1
  Homework #1.
Due 11:45PM, Mar. 23, 2016 Wednesday.
please answer the following problems for the chapter 1 of  the textbook:
  1. Explain Client-Server model for distributed computing by example.
  2. Explain Peer-to-Peer model for distributed computing by example
  3. Compare concepts of Broadcasting, Multicasting, Unicasting.
  4. What are the two generally accepted  angles by which  computer networks can be classified?
  5. Describe some characteristics of the Ethernet.
  6. How is a WAN organized? explain packet-switched principle.
  7. What are two reasons for using layered protocols?
  8. What is the principal difference between connectionless communication and connection-oriented communication?
  9. Explain the relationship between services and protocols.
  10. Which of the OSI layers handles each of the following:
    (a)Dividing the transmitted bit stream into frames.
    (b)Determining which route through the subnet to use.
  11. If the unit exchanged at the data link level is called a frame and the unit exchanged at the network level is called a packet, do frames encapsulate packets or do packets encapsulate frames? Explain your answer.
  12. A system  has an n-layer protocol hierarchy. Applications generate messages of length M bytes. At each of the layers, an h-byte header is added. What fraction of the network bandwidth is filled with headers?
  13. Suppose the algorithm used to implement the operations at layer k is changed, how does this impact operations at layers k-1 and k+1?
  14. Suppose there is a change in the service (set of operations) provided by layer k, how does this impact services at layers k-1 and k+1?
  15. List two ways in which the OSI reference model and the TCP/IP reference model are the same. Now list two ways in which they differ.
  16. Please draw a diagram  showing the OSI reference model.
  17. What is the main difference between TCP and UDP.
  18. When a file is transferred between two computers, two acknowledgement strategies are possible. In the first one, the file is chopped up into packets, which are individually acknowledged by the receiver, but the file transfer as a whole is not acknowledged. In the second one, the packets are not acknowledged individually, but the entire file is acknowledged when it arrives. Discuss these two approaches.
  19. Assume you post a regular letter to a friend, do you think the postal service is a reliable service? if you want to make sure that the letter will arrive at your friend's mail box, think of a protocol based on the regular letter postal service. 
  20. The Internet is made up of a large number of networks. Their arrangement determines the topology of the Internet. A considerable amount of information about the Internet topology is available online. Use a search engine to find out more about the Internet topology and summarize your finding.
  21. Please visit IEEE 802 , make a brief introduction to IEEE 802 LAN/MAN Standards Committee.
  Notes for Submission  
  You may  follow the Electronic Submission Guidelines to submit HW1.
You can create your submission by doing the following for e-submission:
  • 1. Create a file containing your answers
  • 2. mail this file to the class mail, name the mail subject according to the Guidelines