NATIONAL OPEN UNIVERSITY OF NIGERIA
University Village, Plot 91, Cadastral Zone, NnamdiAzikiwe Express Way, Jabi, Abuja
Faculty of Sciences
July 2017
Course Code: CIT 303 Course Unit: 3
Course Title: Principles of Communication Technology
Instruction: Answer Question One and Any Four Other Questions
Time allowed: 2 1/2 hrs
1a. Define the term ‘Data Communication’ 2 marks
b. Outline and discuss four components of data communication. 6 marks
c. Mention 4 different forms in which data is represented today 4 marks
d. Define the following terms
i. Cipher ii. Key 4 marks
e. list and explain three causes of transmission impairment. 6 marks
2a. Enumeratethree major criteria that a networkmust be able to meet 3 marks
b. With the aid of a well labeled diagram write a short note on the following possible connection types
i. Point-to-Point
ii. Multipoint 4 marks
c. Explain what is meant by the physical topology of a network 3 marks
d. List the key elements of a protocol. 2 marks
3a. Describe the OSI model 4 marks
b. State the role of the Session Layer of the OSI model 3 marks
c. Enumerate the five layers of the TCP/IP model 5 marks
4a. Explain why the TCP/IP is the most widely used protocol in the world. 3 marks
b. Define the following terms
i. LAN
ii. WAN
iii. Router
iv. Hub
v. Firewall
vi. Modem 6 marks
c. Write a short note on the technical barriers in VOIP 3 marks
5a. Give two major disadvantage of the bus topology 3 marks
b. Distinguish between guided media and unguided media. 3 marks
c. Explain four characteristics that determine the effectiveness of a data communications system 6 marks
6a. Differentiate between the following
i. A computer with a NOS and one without an NOS
ii. Peer-to-Peer and Client/Server networks
4 marks
b. Define the following modes of data communication between two devices
i. Simplex ii. Half-Duplex iii. Duplex 3 marks
c. Use the Caesar cipher with the key = 9 to encrypt the message “NOUN” 2 marks
d. Enumerate the five services provided by Network Security 3 marks
You can get the soft copy for this course (2014-till date) at a little token or the exam summary answers for this course from 08039407882
Exam summary sample below
