UNIVERSITY EXAMINATIONS: 2013/2014
ORDINARY EXAMINATION FOR THE BACHELOR OF SCIENCE
IN INFORMATION TECHNOLOGY
BIT 2311 NETWORK SYSTEMS DESIGN AND MANAGEMENT
DATE: APRIL, 2014 TIME: 2 HOURS
INSTRUCTIONS: Answer Question ONE and any other TWO
QUESTION ONE
(a) There are many benefits associated with hierarchical network designs. In this
regard, discuss the following benefits:
i. Scalability (3 Marks)
ii. Performance (3 Marks)
(b) To visualize the interaction between various protocols, it is common to use a
layered model. A layered model depicts the operation of the protocols occurring
within each layer, as well as the interaction with the layers above and below it.
State four benefits of using a layered model to describe network protocols and
operations. (4 Marks)
(c) Describe;
i. Four limitations of layer 1 of the OSI reference model. (4 Marks)
ii. How layer 2 addresses each of the above limitations (4 Marks)
(d) Describe the use of topology diagram in the design of network infrastructure.
(6 Marks)
(e) Describe the following switch form factors:
i. Fixed configuration switches (3 Marks) 3 Marks
ii. Modular switches (3 Marks) 3 Marks
QUESTION TWO
(a) With the aid of examples differentiate between end-user devices and network
devices. (5 Marks)
(b) Discuss the three most common causes of network congestion. (6 Marks)
(c) In an Ethernet LAN, devices use one of two types of UTP interfaces – MDI or
MDIX. Discuss how these two interface types affect whether you use a straightthrough or crossover cable. (4 Marks)
(d) State the IEEE 802 standards for the following
i. CSMA/CD (1 Mark)
ii. LLC (1 Mark)
iii. Token Bus (1 Mark)
iv. Token Ring (1 Mark)
v. WLAN (1 Mark)
QUESTION THREE
(a) Describe briefly how the following WAN devices operate:
i. Modem (2 Marks)
ii. CSU/DSU (2 Marks)
iii. Access server (2 Marks)
(b) i. How does a layer 3 switch differ from a layer 2 switch? (3 Marks)
ii. What factors would you take into account when choosing between a layer
3 switch and a router? (3 Marks)
(c) Explain the following Ethernet switch operations:
i. Learning (2 Marks)
ii. Aging (2 Marks)
iii. Filtering (2 Marks)
(d) State two advantages of Network Address Translation (NAT). (2 Marks)
QUESTION FOUR
(a) Discuss any four typical considerations for setting up a remote-site WAN
connection. (8 Marks)
(b) What are the major issues with non-hierarchical networks? (3 Marks)
(c) Explain the procedure for testing cable already installed. (6 Marks)
(d) What is meant by the term “redundancy” when talking about servers and network
design? What is a drawback of building redundancy into a network? (3 Marks)
QUESTION FIVE
(a) More and more companies are finding it beneficial to have teleworkers. With
advances in broadband and wireless technologies, working away from the office
no longer presents the challenges it did in the past.
i. Describe any four benefits of the teleworker solution. (4 Marks)
ii. Teleworkers typically use diverse applications (for example, e-mail, webbased applications, mission-critical applications, real-time collaboration,
voice, video, and videoconferencing) that require a high-bandwidth
connection. Describe any four infrastructure services options that are
available. (4 Marks)
(b) Intermediary devices use the destination host address, in conjunction with
information about the network interconnections, to determine the path that
messages should take through the network. State five functions performed by the
processes running on the intermediary network devices. (5 Marks)
(c) State four major differences between WLANs and wired Ethernet. (4 Marks)
(d) In almost all organizations, Ethernet is the LAN technology of choice. What has
caused organizations to consistently adopt this technology? (3 Marks)
