UNIVERSITY EXAMINATIONS: 2014/2015
ORDINARY EXAMINATION FOR THE BACHELOR OF BUSINESS
IN INFORMATION TECHNOLOGY
BBIT 103 COMPUTER NETWORKS AND MANAGEMENT – DISTANCE LEARNING
DATE: DECEMBER, 2014 TIME: 2 HOURS
INSTRUCTIONS: Answer Question ONE and any other TWO
QUESTION ONE
a) In the OSI reference model, there are seven numbered layers, each of which
illustrates a particular network function. What are the advantages of breaking a
network into seven layers? (5 Marks)
b) With the aid of a relevant diagram, describe the construction of a fibre optic cable.
(5Marks)
c) State any four reasons that would necessitate choosing wireless LANs over
traditional wired LANs. (4 Marks)
d) As a message moves through the network, many factors can prevent the message
from reaching the recipient or distort its intended meaning. These factors can be
either external or internal. Describe briefly any five external factors affecting the
success of communication. (5 Marks)
e) Discuss the three most common causes of congestion in a network. (6 Marks)
f) As the network administrator, you must establish daily and weekly maintenance
routines. List any five tasks that should be done in these routines. (5 Marks)
QUESTION TWO
a). (i) Define the term convergence s used in Computer networks. (1 Mark)
(ii) Converged networks have existed for a while now, but were only feasible
in large enterprise organizations. Why? (4 Marks)
(iii) Why is it difficulty for some organizations to make a decision to move
towards converged networks? (2 Marks)
b) Discuss the following concepts as used in computer networks:
(i) Fault Tolerance (4 Marks)
(ii) Scalability (4 Marks)
c) State five major reasons why computers are networked. (5 Marks)
QUESTION THREE
a) With the aid of examples differentiate between end-user devices and network
devices. (5 Marks)
b) Discuss the following transport layer functions:
(i) Reliable Delivery (2 Marks)
(ii) Same Order Delivery (2 Marks)
(iii) Flow Control (2 Marks)
c) To accomplish their purpose, Ethernet LAN switches use five basic operations.
Explain the following ethernet switch operations:
(i) Learning (2 Marks)
(ii) Aging (2 Marks)
(iii) Filtering (2 Marks)
d) State the three major characteristics of WANs. (3 Marks)
QUESTION FOUR
a) WANs are groups of LANs connected together with communications links from a
service provider. Because the communications links cannot plug directly into the
LAN, it is necessary to identify the various pieces of interfacing equipment.
Describe the functions of the following WAN devices:
(i) Router (2 Marks)
(ii) CSU/DSU (2 Marks)
(iii) Modem (2 Marks)
(iv) Communication server (2 Marks)
b) Explain any four routing metrics used by routing protocols to determine the best
path for a packet. (4 Marks)
c) As systems become increasingly distributed, cheaper, and innovative,
greater focus has been placed on strategically arranging them using effective network design practices to ensure survivability and performance. Strategies and
practices used in the past to deliver survivable and well-performing networks are
being revised in light of more recent IT trends and world events.
(i) When designing a LAN, discuss why it is necessary to consider the concept of Network Continuity. (3Marks)
(ii) Discuss the concept of disaster recovery (3 Marks)
(iii) Explain the considerations to take into account in order to ensure
the designed LAN lasts 7 to 10 years (2 Marks)
QUESTION FIVE
Due to its recent expansion caused by a higher intake of students, a certain college in
Nairobi has been forced to rent and occupy four (4) floors of a 10-storey building. The
college intends to use the lower two floors for administration and lecturers’ offices and
the third floor for computer labs while the fourth one dedicated for lecture rooms. The
college also intends to set up a LAN, which is adequately secure and easy to manage. As
the Network Administrator/Engineer, you are:
Required:
(i). What type of network will you set up for the college? (1 Mark)
(ii). You are required to the different departments of the organization and control flow of
data between the departments. Explain how this will be achieved. (7 Marks)
(iii). What are the security threats that are likely to occur? Provide a possible solution for
each threat. Note: Provide only three (3) threats. (6 Mark)
(iv). Briefly describe a solution that you will provide for the college for Internet connectivity. (4 Marks)
(v). Differentiate between “User Authentication” and “User Authorisation”.
(2 Marks)
