Assignment 02: Semester 2

Assignment 02: Semester 2

Computer Networks

COS2626

Semester 2

School of Computing

IMPORTANT INFORMATION:

This tutorial letter contains Assignment 02 for Semester 2

2

Assignment 02: Semester 2

Assignment 02 Semester 2

Due Date 12th September 2014

Unique Assignment number 856272

Study Material Chapters 8 to 11, 14

Submission Procedure Postal box submission or electronically via myUNISA

Number of Questions 7

Number of Marks 60

Assignment weight 60%

Question 1 [14]

The following questions are based on wireless networking.

1.1 Define the term wireless spectrum. [1]

1.2 Describe the CHARACTERISTICS wireless transmissions have in common with

wired transmissions.

[2]

1.3 Describe the DIFFERENCE between wireless and wired transmissions. [1]

1.4 Explain why wireless networks are not laid out using the same topologies as wired

networks.

[1]

1.5 Which WLAN (Wireless Local Area Network) architecture is depicted in the

following diagram?

[1]

1.6 Explain the ADVANTAGE of having WLANs support the same protocols (for

example, TCP/IP) and operating systems (for example, UNIX, Linux, or Windows)

as wired LANs.

[1]

1.7 Describe the use of CSMA/CA (Carrier Sense Multiple Access with Collision

Avoidance) to access a shared medium.

Note the significance of using ACK packets to verify every transmission.

[7]

Assignment 02: Semester 2

3

Question 2 [9]

Match each statement with the correct term below. Write only the number of statement and

the corresponding term, e.g. 2.1-a

2.1 Displays TCP (Transmission Control Protocol) /IP (Internet Protocol) statistics and

details about TCP/IP components and connections on a host.

2.2 Allows an administrator to query the DNS database from any computer on the network

and find the host name of a device by specifying its IP address, or vice versa.

2.3 Useful only on networks that run Windows-based operating systems and NetBIOS.

2.4 Allows an administrator to query a DNS (Domain Name Server) database and find the

host name associated with a specific IP address or vice versa.

2.5 The TCP/IP administration utility for use with Windows operating systems.

2.6 Allows you to view a hosts routing table.

2.7 Used if an administrator already know a hosts name and wants to learn its IP address.

2.8 The TCP/IP configuration and management utility used on UNIX and Linux systems.

2.9 Uses ICMP (Internet Control Message protocol) ECHO requests to trace the path from

one networked node to another, identifying all intermediate hops between the two nodes.

a. ipconfig utility

b. ifconfig utility

c. netstat utility

d. nbstat utility

e. host utility

f. dig utility

g. nslookup utility

h. route utility

i. traceroute utility

Question 3 [3]

Study the following diagram depicting the elements of virtualization. Identify components A,

B and C respectively.

4

Question 4 [4]

Study the following diagram depicting a VPN (Virtual Private Network) connection and answer

the questions that follow.

4.1 Define a VPN. [1]

4.2 What are TWO important considerations when designing a VPN? [2]

4.3 What does the letter 'A' in the diagram represent? [1]

Question 5 [5]

Name and discuss FIVE factors that cloud computing is distinguished by.

Question 6 [11]

The following questions are based on security policies.

6.1 Define a security policy. [3]

6.2 Name THREE typical goals for security policies. [3]

6.3 Name FOUR possible subheadings for the policy outline. [4]

6.4 A security policy should define what confidential means to the organization. Define

term confidential.

[1]

Assignment 02: Semester 2

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Question 7 [14]

The following questions are based on data backup.

7.1 Define the term backup [1]

7.2 Define the term optical media and provide examples. [4]

7.3 Name THREE DISADVANTAGES of optical media. [3]

7.4 Describe how tape backup might be implemented on both small and large

networks.

[2]

7.5 Describe how to perform network backups if an organization does not have a WAN

or a high-end storage solution.

[3]

7.6 Describe the Grandfather-Father-Son backup rotation scheme. [1]