Computer Networks Answers

A. The motorway management perceives that the waiting time computed in (a) above is not acceptable and it wishes to reduce it, first, by adding an extra tollbooth assistant to help improve the service rate to 250 motorists every 8-hour-day. The tollbooth attendant will be paid a monthly salary of GH¢400. The second option is that management can add a toll-operated machine which will cost GH¢3,000 and this amount is a free gift from the Minister. This option will reduce the arrival rate to 35 motorists every 2 hours. However, management will have to pay the operator who will man the toll-operated machine a monthly salary of GH¢550. Whichever option management adopts; they avoid lost sales of GH¢1,200.00 per month for every minute that average waiting time is reduced. Advise management which option it must adopt? 

Draw an ER diagram for a university library information system which stores

information about books, journals, publishers, students, staff, borrowing of books,

and reservation of books. Note that the library may have more than one copy for

some of the books. You must show the entities, relationships and attributes along

with the cardinality constraints and proper symbols.

Choose ONE of the below security topics from chapter 22 of the Dordal (2019) course text. Research the topic, then provide a summary of the technology and how it works. Please use one additional outside source from the Internet to support your findings.

1. Network Intrusion Detection
2. Secure Shell (SSH)
3. Transport Layer Security (TLS)
4. Public Key Encryption

Note any areas where you may want or need some further explanation. Ask questions of your fellow classmates.

Scenario

In computer networking two versions of IP address are used i.e., IPv4 and IPv6. What is your point of view, will IPv6 totally replace IPv4 or IPv4 will co-exist with IPv6? Justify your opinion with two solid reasons.

Note: Format of your answer should be as follow:

Your Opinion (Yes/No):

 Reason 1:

 Reason 2:

Perform the subnetting on the below IP Address and find out the number of networks, network of, first host, last host, and broadcast id of each network.          (10 Marks)                                                                                

                        IP Address: 210.220.150.0/28   

Discuss three responsibilities that an operating system has for file management in a computer system.

UDP and TCP use the checksums to detect the error in message. Suppose you have the following data 0010110000011101110. What is the checksum of these data using 4 bits chunks?

Answer the following in your own words.  

1. Why does the maximum packet lifetime have to be large enough to ensure that not only the packet but also its acknowledgments have disappeared?
2. Give one potential disadvantage when Nagle's algorithm is used on a badly congested network.
3. Give two examples of cases where TCP sends data-less packets on an established connection (which is not being torn down).
4. Exercise 5.0 from section 12.24 of the textbook:
5. Suppose you see multiple TCP connections on your workstation in state FIN_WAIT_1. What is likely going on? Whose fault is it?
6. What might be going on if you see connections languishing in state FIN_WAIT_2?

Distinguish between two main categories of processor registers; and give examples to illustrate your answer.