Preparing a Design Document

As you finalize your network design and prepare to present it to your customer, there are a few steps you should take to ensure that all of your hard work is presented in the best way possible. You want to emphasize the strengths of Cisco’s solutions along with your company’s ability to implement these solutions.

The two methods you can use to present your work are

• Respond to a customer’s RFP.

• Prepare a design document.

If the customer issued an RFP, they likely specified in the RFP the format in which you need to respond. You should prepare your documentation accordingly. However, if the customer did not issue an RFP, then you need to prepare a design document to present your proposed solution. Cisco recommends that you include the following five sections in your design document:

• Executive summary

• Design requirements

• Design solution

• Summary

• Appendixes

Let’s take a look at each of these sections in more detail.

Section 1: Executive Summary

As the name implies, the executive summary is a summary of your design. The actual design will come later; at this point you are trying to create the big picture. Keep this section brief—one or two pages should be adequate. The target audience for this section is specified in the name of this section: the executives of the company. Emphasize solutions that will be provided by both you and Cisco. Be specific, but don’t get too caught up in details. That will come later.

Cisco has made some recommendations for items that you could include in the executive summary. You might include one to two paragraphs on any of the following:

• The purpose of the project, especially how the project will help your customer’s company achieve its strategic objectives.

• Your network design—more specifically, how your design fulfills the purpose of the project. Tie this information to helping the company achieve its strategic objectives.

• Implementation issues. Mention both technical constraints as well as business constraints.

• Benefits offered by your solution. Once again, these should be tied to the customer’s strategic objectives.

Notice that the emphasis is on the customer and the customer’s objectives. It is crucial to keep in mind that even after all the work that you have invested thus far, this is the customer’s network. The customer likely has specific reasons for making the decision to install it. If you have done your homework, you will know these reasons (the strategic objectives), and you can orient your solution towards fulfilling these objectives. After all the work you have done, this is where you can really show your customer that your design solves their problems.

Section 2: Design Requirements

The design requirements of your design document lays out the information that you gathered before the design process began. You may recall that Chapter 4, “Pre-Design Procedures,” discussed gathering information on the customer’s current network, and then meeting with the customer to evaluate their needs and expectations for the new network. This section is where you present this information. You are not presenting your design yet, but you are discussing the customer’s current network and what the customer wants to accomplish. Therefore, the administrative or technical data that you gathered when completing the steps in Chapter 4 can be included here.

As you describe the customer’s current network, you may wish to include any of the following:

• A high-level topology map of the customer’s current network

• Current applications, protocols, hardware, network management systems, etc.

• Router status, network utilization statistics, bottlenecks, reliability issues, and network health

• Business constraints such as budgets, training issues, staffing, scheduling of installation, etc.

As you move on to discuss the customer’s needs and expectations, you may wish to include the following:

• A high-level topology map of the customer’s proposed network

• Requirements for security, reliability, performance, and manageability

• Any new business constraints identified by the customer

Section 3: Design Solution

The design solution section is where you (finally) get to propose your solution in detail. All of the work completed during Chapters 5 through 11 can be included here. However, as with the executive summary, you do not want to focus on your design; emphasize how your design solves the customer’s requirements! Remember, the preceding section presented an analysis of the customer’s current network and the customer’s requirements and expectations. Now, you want to present a design solution that meets the objectives described in the design requirements section.

As mentioned, any of the information gathered in Chapters 5 through 11 can be described here, including

• Topology issues, such as using the three-part firewall or hierarchical design.

• Hardware recommendations for LAN and WAN devices. Be thorough in discussing any new technologies you introduce, such as ISDN, ATM, or switching. Discuss specific Cisco model numbers for the devices that you are deploying.

• Network addressing scheme, including the use of private addressing and NAT if applicable. You may also want to describe a network- naming standard.

• Routing protocols to be used. You may need to include details on items such as redistribution or DDR.

• Bridging protocols, if they will be used.

• Any special IOS software features that you will be using such as access lists, encryption, compression, traffic shaping, or queuing.

• Network management solutions.

Section 4: Summary

Your summary needs to be brief, like the executive summary. You want to summarize how your solutions (presented in the design solution section) solve the customer’s requirements (presented in the design requirements section). You may also wish to point out the specific advantages of deploying a Cisco solution over other solutions, as well as any specific advantages offered by your company.

Section 5: Appendixes

You may wish to include appendixes in your design document to provide additional information. However, these appendixes should supplement the material in the preceding sections; that is, your presentations in those sections should not depend on these appendixes to make their point. Tempted as you may be to include volumes of information, answer the following question honestly before you do it:

When was the last time you read the appendixes of a book?

Of course, this question does not apply to this book, as I am sure that you will absolutely devour the appendixes. However, you get the point.

Should you choose to include appendixes, the following are Cisco recommended topics:

• A contact list, including e-mail, telephone, and mailing information for any contacts at your customer’s company, your company, or even Cisco

• A proposed schedule for implementing the network

• Any additional details on your design

• The results of your prototype (covered next)