System Analysis and Design

Note to Students: After you complete the Practice Tasks, click here to view the sample answers and check your work. Your answers might vary from these examples and still be correct. The intent is to give you a sample to guide you and serve as a reference. When you complete the Practice Tasks and review the sample answers, please return to this page and complete the Challenge Tasks.

Background The IT team at Game Technology is working on an overall architecture for the new C3 system.

They solicited RFPs from several hardware vendors, and decided to work with Network

Illusions, a well-known local firm. Your job is to help analyze the server test results, and to draw

network diagrams when requested.

The Network Illusions sales rep recommended a Model DX server for the C3 network, and

submitted the following data, which shows projected network response times for various

numbers of Game Technology users:

Practice Tasks Task 1. Using the data provided, create an XY chart that shows Response Time on the Y

(vertical) axis and Number of Users on the X (horizontal) axis. You learned about XY

charts in Chapter 2 of your textbook. Describe the results and your interpretation of the

data.

Task 2. Draw a bus network with a server, six workstations, a printer, a scanner, and a wireless access point (WAP). Also, determine how many separate data paths are needed in a

mesh network with four nodes. Five nodes?

Challenge Tasks After you complete the Practice Tasks, you learn about new developments at Game Technology.

Although the spec was for a Model XP server, Network Illusions delivered a newer model, called

the DX+. The vendor sales rep said that performance would be the same or better, but the IT

team decided to run a series of response time tests. The results are as follows:

Critical Thinking Challenge: Tasks Page

Projected Data: Server Model DX Number of Users

10 20 30 40 50

Response Time (sec) .01 .015 .02 .025 .03

Task 1. Use the actual test data to create another XY chart, similar to the first one. Describe the results and your interpretation of the data.

Task 2. Draw the same network as a star topology with a central switch. Also determine how many separate data paths are needed in a mesh network that has six nodes.

Projected Data: Server Model DX + Number of Users

10 20 30 40 50

Response Time (sec) .01 .015 .02 .03 .05

Chapter 10: System Architecture

Note to Students: After you complete the Practice Tasks and review the sample answers, please click here to return to the Tasks page and complete the Challenge Tasks.

Background The IT team at Game Technology is working on an overall architecture for the new C3 system.

They solicited RFPs from several hardware vendors, and decided to work with Network

Illusions, a well-known local firm. Your job is to help analyze the server test results, and to draw

network diagrams when requested.

The Network Illusions sales rep recommended a Model DX server for the C3 network, and

submitted the following data, which shows projected network response times for various

numbers of Game Technology users:

Sample Answers Task 1. Using the data provided, create an XY chart that shows Response Time on the Y

(vertical) axis and Number of Users on the X (horizontal) axis. You learned about XY

charts in Chapter 2 of your textbook. Describe the results and your interpretation of the

data.

Critical Thinking Challenge: Sample Answers Page

Projected Data: Server Model DX Number of Users

10 20 30 40 50

Response Time (sec) .01 .015 .02 .025 .03

When the projected data on Server Model DX is plotted, it reveals a linear relationship

where the response time closely correlates to the number of users. As the number of

users grows, the response time increases proportionately. Given this relationship, we

project that the server offers stable and predictable performance across the range of

users specified.

Further analysis would be required to determine at what point, if any, this model’s

performance changes from a predictable linear relationship, to something else. This

point is sometimes referred to as the “knee” in the curve. For example, at a certain

point, the response time could begin to climb exponentially.

Task 2. Draw a bus network with a server, six workstations, a printer, a scanner, and a wireless access point (WAP). Also, determine how many separate data paths are needed in a

mesh network with four nodes. Five nodes?

To determine the number of paths, you can just draw a sketch and count the paths. This

works with relatively small numbers, but not so well if there are dozens, or hundreds of

nodes. For example, in Figure 10-28 on page 428, there are five nodes, including the

server, and a total of ten data paths.

If you are math-oriented, you can use a formula to determine the number of data paths.

This formula is commonly used to analyze permutations and combinations of values.

Here’s how it works: Assume that the number of nodes is represented by “N.”

The formula for the number of data paths is:

N * (N-1)

2

Therefore, with four nodes, we have

4 * (4-1)

2

or

12/2 = 6

With five nodes, we have

5 * (5-1)

2

or

20/2 = 10