NATIONAL OPEN UNIVERSITY OF NIGERIA

UNIVERSITY VILLAGE, PLOT 91, CASDASTRAL ZONE, NNAMDI AZIKIWE EXPRESS WAY, JABI, ABUJA.
FACULTY OF SCIENCES
OCTOBER 2013 EXAMINATION

COURSE CODE:                                                                              CIT 311                                                                               

COURSE TITLE:                                                                             Computer Networks

DURATION:                                                                                     2½ Hours

INSTRUCTIONS:                                                                            Answer any five (5) questions.

Q1(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)

Q2(a)  In transmission, what is the difference between full duplex and half duplex operation(6 marks)

     (b)  List and discuss the sub layers of the Data link layer                                                        (8 marks)

Q3.       State seven typical routing protocols and their associated network operating systems                    (14 marks)

Q4(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)

Q5(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)

Q6.       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)

Q7(a)  List and discuss the two types of categories of an ATM connection                               (6 marks)

     (b)  State and enumerate the three types of interfaces which an ATM switch supports.     (8 marks)