UNIVERSITY EXAMINATIONS: 2016/2017
EXAMINATION FOR THE DIPLOMA IN INFORMATION TECHNOLOGY
DIT 402 FUNDAMENTALS OF COMPUTER NETWORKS
DATE: AUGUST, 2017 TIME: 2 HOURS
INSTRUCTIONS: Answer Question One & ANY OTHER TWO questions.
QUESTION ONE [30 MARKS] – COMPULSORY
a) Define the following terms and acronyms 10Marks
i. GRIN
ii. WAN
iii. guided media
iv. encryption
v. topology
vi. OSI
vii. multiplexing
viii. network
ix. Mbps
x. EMI
b) List two advantages and two diadvantages of computer networks 4Marks
c) Briefly describe the following types of network topologies 6Marks
i. Ring
ii. Bus
iii. Mesh
d) Many networks are implemented with the star topology. Give and explain two reasons why this
topology is popular 4Marks
e) List three logical threats to network security. For each suggest a solution 3Marks
f) An optical fiber is marked RL=2GbpsKm. Calculate the data rate if the cable is (i) 500m long
and (ii) 2.5Km long. Explain the difference in data rate. 3Marks
QUESTION TWO [20 MARKS]
a) Network security relvolves around Integrity, Confidentiality and Availability. Define each of
the highlighted terms 6Marks
b) Describe any encryption method. Give an example 4Marks
c) An important role of the network layer is to provide logical adresses, better known as IP
addresses. Using a sample IP adress show the class, net ID, comp ID and maximum number of hosts for
the network. 5Marks
d) Describe the construction and operation of the coaxial cable 5Marks
QUESTION THREE [20 MARKS]
a) Give the function, an advantage and a disadvantage of each of the following devices
12Marks
i. router
ii. brouter
iii. repeater
iv. hub
b) List and give the functions of the top three layers of the OSI model 8Marks
QUESTION FOUR [20 MARKS]
a) Discuss each of the following netork impairments 8Marks
i. scater
ii. EMI
iii. modal dispersion
iv. attenuation
b) You are to advice a CEO on the media to use for a section of the network that will pass through
a factory with many motors. You have a choice of UTP, GRIN and COAX cables. You are to pick the
best cable while considering the cost. Make a choice and explain the arguments for and against the
cables available 6Marks
c) Explain the difference between signalling and switching 3Marks
d) Explain the differece between circuit switching and packet switching 3Marks
QUESTION FIVE [20 MARKS]
a) List four components of a computer network. Give the role of each 6Marks
b) Give three functions of the NIC in a computer 3Marks
c) Computer cables in a bus network must be properly terminated. Explain the meaning of the
term in bold font and why it must be that way 2Marks
d) Give two types of multiplexing. Mention an advantage of each 4Marks
e) Describe any one routing algorithm. Give a worked example. 5Marks
