NATIONAL OPEN UNIVERSITY OF NIGERIA
14–16 AHMADU BELLO WAY, VICTORIA ISLAND LAGOS SCHOOL OF SCIENCE AND TECHNOLOGY OCTOBER/NOVEMBER 2014 EXAMINATION
COURSE CODE: CIT 311
COURSE TITLE: COMPUTER NETWORKS CREDIT UNIT: 3CREDIT UNITS
TIME: 3 HOURS
INSTRUCTION: ANSWER ANY FOUR QUESTIONS IN ALL
1a. What is Computer network [5 marks]
1b. Write short note on geographical coverage classification of Networks and give one
example each [12.5 marks]
2a Write short note on the Goals/Motivation of Computer Network [10 mark]
2b. Enumerate the three characteristics of LANs that distinguished it from other kinds of networks:
3a. What is Packet switched network [7.5 marks]
3b. Write short note on the two types of Network [10 marks]
4a. What is a digital signal [5.5 marks]
4b. Differentiate between OSI Reference Model & TCP Reference Model [12marks]
5a. Write short note on IEEE Standard 802.4 and Ethernet [8.5 marks]
5b. Write short note on IEEE Standard 802.3 and Ethernet [9marks]
6a. Write short note on IEEE Standard 802.5 and Ethernet [7.5 marks]
6b. Differentiate between a continuous and discrete signal [10marks]
*National Open University Exam Past Question – CIT 311 MAY/JUNE 2012 EXAMINATION*
NATIONAL OPEN UNIVERSITY OF NIGERIA
14–16 AHMADU BELLO WAY, VICTORIA ISLAND LAGOS SCHOOL OF SCIENCE AND TECHNOLOGY
MAY/JUNE 2012 EXAMINATION
CIT 311 Computer Networks
Time: 3hrs
Instruction: Answer any five (5) questions.
1a. Give the full meaning of the following acronyms, within the context of computer networks:
i. GFC (2 marks)
ii. ATM (2 marks)
iii. PTI (2 marks)
iv. VPI (2 marks)
1b. Describe how the ATM protocol works. (12 marks)
2. Specify the status of the modem indicator light in the following settings:
2a. When the modem is powered up. (4 marks)
2b. If the computer is ready to send or receive data. (4 marks)
2c. When receiving a call. (4 marks)
2d. If the modem is sending data. (4 marks)
2e. When the modem detects the remote modem’s carrier. (4 marks)
3a. Briefly explain the concept of ring topology. (4 marks)
3b. Give a good reason why asynchronous transfer modes are considered appropriate for multimedia communication. (4 marks)
3c. State four (4) requirements for an efficient traffic control mechanism. (12 marks)
Specify the main function of the following:
Routers
Transport Layer )
iii. Bridges ) 5 marks each iv. Repeaters
v. Datagrams
(20 marks)
5a. Distinguish between Baseband and Broadband Communication. (10marks)
5b. Give five (5) common applications of Integrated Services Digital Network (ISDN) (10 marks)
6. Electronic mails have become very popular in transferring information, specify any ten
(10) features of this mode of information transfer. (20 marks)
7a. In the context of computer networks, what does the acronym RIP represent?
(1 mark)
7b. Describe three (3) common problems that can occur in RIP.
(9 marks)
7c. State any five (5) tasks which a modem can perform. (10 marks)
*National Open University Exam Past Question – CIT 311 October, 2013 Examination*
NATIONAL OPEN UNIVERSITY OF NIGERIA
14/16, Ahmadu Bello Way, Victoria Island
SCHOOL OF SCIENCE AND TECHNOLOGY October, 2013 Examination
COURSE CODE: CIT 311
COURSE TITLE: Computer Networks
CREDIT UNIT: 3
TIME: 21/2 hours
INSTRUCTION: Answer any five (5) questions. Each question carries 14 marks
1.(a) List and discuss three classifications of networks (8 marks)
(b) With the aid of a diagram give a brief description of the concept of star topology (6 marks)
2.(a) In transmission, what is the difference between full duplex and half duplex operations (6 marks)
(b) List and discuss the sub layers of the Data link layer (8 marks)
3. State seven typical routing protocols and their associated network operating systems (14 marks)
4.(a) What is the difference between Baseband and Broadband Communication (10 marks)
(b) Give any four regular applications of Integrated Services Digital Network (4 marks)
5.(a) Give the full meaning of the following acronyms within the context of computer networks: (i) VPI
(ii) VCI (4 marks)
(b) State any five task which a modem can perform (10 marks)
6. Specify the status of the modem indicator light in the following settings:
(i) When not receiving calls (4 marks)
(ii) When modem is getting data or a command from the computer (4 marks)
(iii) When Modem is sending data (4 marks)
(iv) If the modem is powered up (2 marks)
7(a) List and discuss the two types of categories of an ATM connection (6marks)
(b) State and enumerate the three types of interfaces which an ATM switch supports. (8 marks)