W1-2-60-1-6
JOMO KENYATTA UNIVERSITY
OF
AGRICULTURE AND TECHNOLOGY
University Examinations 2016/2017
FIRST YEAR FIRST SEMESTER EXAMINATION FOR THE DEGREE
OF BACHELOR OF SCIENCE IN INFORMATION TECHNOLOGY
BIT 2108: COMPUTER NETWORKS
DATE: DECEMBER 2016 TIME: 2 HOURS
INSTRUCTIONS: ANSWER QUESTION ONE AND ANY OTHER TWO QUESTIONS
Question One (30 Marks)
a) Explain the following terms:
(i) Protocol (2 Marks)
(ii) Modulation (2 Marks)
b) Distinguish the following networks:
(i) LAN and PAN (3 Marks)
(ii) MAN and WAN (3 Marks)
c) Explain the functions of the following devices and state where they reside in the OSI model:
(i) Bridge (2 marks)
(ii) Router (2 marks)
d) Describe any four (4) network management functions. (8 Marks)
e) With the aid of a diagram, explain the difference between straight through and
cross-over data cables and state two (2) applications of each. (8 Marks)
Question Two (20 Marks)
a) Distinguish the following routing algorithms:
(i) Static and dynamic (3 Marks)
(ii) Flat and Hierarchical (3 Marks)
(iii) Link state and distance vector (3 Marks)
b) Explain the 5 – 4- 3 Ethernet repeater rule. (2 Marks)
c) Explain the following Ethernet standards, stating the cable specifications:
(i) 10 Base 2 (1 Mark)
(ii) 10 Base 5 (1 Mark)
(iii) 100 Base T (1 Mark)
d) With the aid of a diagram, describe how data is transmitted in a token ring network. (6 Marks)
Question Three (20 Marks)
a) Describe any four (4) protocols that reside in the TCP/IP application layer. (4 Marks)
b) Describe any five (5) factors to be considered when selecting network cables. (5 Marks)
c) With reference to security in distributed systems, explain any five (5) attacks on a communication channel. (5 Marks)
d) With the aid of a diagram, describe the components of a fibre optic system. (6 Marks)
Question Four (20 Marks)
a) Explain the functions of the following layers of OSI model:
(i) Presentation (2 Marks)
(ii) Transport (2 Marks)
(iii) Network (2 Marks)
b) Explain five (5) differences between a server based network and a peer to peer network. (5 Marks)
c) With the aid of a waveform illustrations encode the data stream 10111011 to the following formats:
(i) Bipolar R2 (3 Marks)
(ii) Bipolar NR2 (3 Marks)
(iii) Manchester Code (3 Marks)
Question Five (20 Marks)
a) Distinguish the following:
(i) IP address and MAC address (4 Marks)
(ii) Frequency Division Multiplexing and Time Division Multiplexing (4 Marks)
b) Explain four (4) advantages of fibre optic cables. (4 Marks)
c) With the aid of a diagram, explain how data changes when two hosts communicate via SMTP protocol. (8 Marks)
