W1-2-60-1-6
JOMO KENYATTA UNIVERSITY
OF
AGRICULTURE AND TECHNOLO7GY
University Examinations 2018/2019
SECOND YEAR FIRST SEMESTER EXAMINATION FOR THE DEGREE
OF BACHELOR OF BUSINESS INFORMATION TECHNOLOGY
HBT 2105: DATA COMMUNICATION AND COMPUTER NETWORK
DATE: APRIL 2019 TIME: 2 HOURS
INSTRUCTIONS: ANSWER QUESTION ONE AND ANY OTHER TWO QUESTIONS
Question One (30 Marks)
a) With the aid of a diagram, describe the elements of a data communication system. (6 Marks)
b) Explain five (5) factors to be considered when selecting cabling media. (5 Marks)
c) Explain two (2) limitations of microwave transmission media. (4 Marks)
d) Explain the difference between the following with reference to networking:
(i) Physical topology and logical topology (4 Marks)
(ii) LAN and WAN (4 Marks)
(iii) Intranet and Extranet (4 Marks)
e) Explain the role of a gateway and state where it resides in the OSI model. (3 Marks)
Question Two (20 Marks)
a) Explain the difference between the following:
(i) Guided and unguided transmission media (2 Marks)
(ii) Half duplex and full duplex transmission mode (2 Marks)
(iii) Synchronous and asynchronous transmission (2 Marks)
(iv) Serial and parallel transmission (2 Marks)
b) With the aid of a diagram, describe the operation of the FDDI topology access method. (4 Marks)
c) Explain four (4) advantages of fibre optic transmission system. (8 Marks)
Question Three (20 Marks)
a) Explain the difference between the following:
(i) Circuit switching and packet switching (4 Marks)
(ii) Peer to peer and server based networks (4 Marks)
(iii) Coaxial thinnet and coaxial thick net (4 Marks)
b) Explain the following modulation schemes:
(i) Time division multiplexing (3 Marks)
(ii) Frequency division multiplexing (3 Marks)
c) Explain the term CRC (2 Marks)
Question Four (20 Marks)
a) Explain the difference between:
(i) Multiplex and demultiplexer (4 Marks)
(ii) Dial up connection and leased connection (4 Marks)
b) Explain four (4) situations where communication via radio signals for LAN may be preferable over cable communication. (4 Marks)
c) Explain the need for standard in data communications. (2 Marks)
d) Explain three (3) standards for data communication. (3 Marks)
e) Explain the differences between connection oriented and connection less data transmission. (3 Marks)
Question Five (20 Marks)
a) With the aid of a diagram, describe the TCP/IP model, illustrating how it maps to the OSI model. (10 Marks)
b) Explain the operation of CSMA/CD. (10 Marks)
