Chp. 6 Chapter Questions

Question 1

What are the keys to designing a successful data communications network?

Answer 1

• needs analysis,
• developing one or more physical network designs,
• designing to operate and maintain with minimal staff intervention.

Question 2

How does the traditional approach to network design differ from the building block approach?

Answer 2

• Traditional network designs used a very structured approach for the analysis and design.
• This by default built in limitations to the growth and need to change network designs as the needs of the organization and technology itself changed.

Question 3

Describe the three major steps in current network design.

Answer 3

Needs analysis, technology design and cost assessment.

Question 4

What is the most important principle in designing networks?

Answer 4

Completing a thorough needs analysis that takes into consideration the needs of the organization over the short and long-term.

Question 5

Why is it important to analyze needs in terms of both application systems and users?

Answer 5

Because you want to make sure that the network can support the bandwidth and other operational characteristics required by the user applications.

Question 6

Describe the key parts of the technology design step.

Answer 6

• It examines the available technologies and assesses which options will meet the users’ needs.

Question 7

How can a network design tool help in network design?

Answer 7

• Good modeling tools not only produce simulation results, but also highlight potential trouble spots (e.g., servers, circuits, or devices that experienced long response times).
• The very best tools offer suggestions on how to overcome the problems that the simulation identified (e.g., network segmentation, increasing from T1 to T3).

Question 8

On what should the design plan be based?

Answer 8

based on:

• the geographic scope of the network,
• the number of users and applications,
• the current and future network needs of the various network segments,
• the costs of the network and maintaining the network.

Question 9

What is an RFP, and why do companies use them?

Answer 9

1. request for proposal (RFP)
2. RFPs specify what equipment, software, and services are desired and ask vendors to provide their best prices

Question 10

What are the key parts of an RFP?

Answer 10

• Background Information
• Network Requirements
• Service Requirements
• Bidding Process
• Information required from vendor

Question 11

What are some major problems that can cause network designs to fail?

Answer 11

• Technology design problems
• Needs analysis problems
• Overall problems with the design process.

Question 12

What is a network baseline, and when is it established?

Answer 12

1. provide a clear picture of the present sequence of operations, processing times, work volumes, current communication network (if one exists), existing costs, and user/management needs.
2. needs analysis step

Question 13

What issues are important to consider in explaining a network design to senior management?

Answer 13

• One of the main problems in network design is obtaining the support of senior management.

Question 14

What is the turnpike effect, and why is it important in network design?

Answer 14

1. The turnpike effect results when the network is used to a greater extent than was anticipated because it is available, is very efficient, and provides new services.
2. It is important in network design not only because usage is higher than anticipated, which slows response time, but also because the types of messages may be different than those for which the network was originally designed.

Question 15

What are the seven network architecture components?

Answer 15

• LANs
• building backbones
• campus backbones
• WANs
• Internet access
• e-commerce edge and data centers.

Question 16

What is the difference between a building backbone and a campus backbone, and what are the implications for the design of each?

Answer 16

1. A building backbone distributes network traffic to and from the LANs while Campus backbone connects all buildings on one campus
2. The campus backbone is usually faster than the backbones we use inside buildings because it typically carries more traffic than they do.

Question 17

What are typical speeds for the LAN, building backbone, and campus backbone? Why?

Answer 17

LAN – 1 Gbps

Building backbone – 10 Gbps

Campus backbone – 40 Gbps

In most cases, because network traffic is consolidated onto the broader networks, the building backbone is one speed level above the LAN and the campus backbone speed is one speed level about the building backbone.

Question 18

What is a bottleneck, and why do network managers care about them?

Answer 18

1. A bottleneck is a place where performance of an entire system is limited by capacity at some point in a network.
2. Managers care about them because these are points that can be fixed or upgraded and after doing so, the network performance becomes improved.

Question 19

Is it important to have the fastest wireless LAN technology in your apartment? What about in the library of your school? Explain.

Answer 19

1. It is not necessarily important to have the fastest wireless LAN technology in your apartment because that technology may be faster than your Internet access to your apartment.
2. The answer is similar as it applies to the library within your school. As long as the traffic stays within the library, a fast wireless network is beneficial.

Question 20

Why do you think some organizations were slow to adopt a building-block approach to network design?

Answer 20

• slow because this approach requires network managers to speak the language of upper management (cost, network growth, reliability) rather than the language of technology (Ethernet, ATM, and DSL).

Question 21

For what types of networks are network design tools most important? Why?

Answer 21

1. Large, complex networks require the use of network design tools.
2. The many devices on such systems and the variety of services requested by users requires that network managers organize and manage the process using system management software.