a lighted staircase

What Are The Next Steps In A WAN Redesign?

a lighted staircaseMost of the network organizations that I work with realize that they have the same basic WAN design as they did 5 to 10 years ago. They also realize that there is a lot of WAN-focused technology being brought to market. That leaves these organizations asking a critical question: How do I get from where I am now to my next generation of WAN design?

When I work with a network team on a project such as implementing a next generation WAN, I strongly suggest that we start by identifying management’s hot buttons. The point of that approach is that at various times in the project, whether that is getting permission to do a trial or requesting money to buy new equipment, the team is going to need management’s buy-in. It is a lot easier to get that buy-in if the team identifies up front the issues that are most important to management and works to address those issues throughout the project.

Identify the WAN Challenges

A key step in getting ready to address the issues that management is likely to have is to identify the key challenges facing your WAN. For most companies those challenges include improving application performance, increasing availability, reducing cost and increasing security. However, since every company is somewhat unique, just identifying these challenges isn’t enough. The team should also assign a weight to each challenge.

One technique that I often use is to give each team member 100 points and ask them to assign weights to each challenge. To exemplify how this works assume that there are just two team members, team member A and team member B, and just the four WAN challenges mentioned above. As shown in Table 1, team member A thinks that all challenges are equally important while team member B thinks that improving application performance is much more important than the other challenges. Since there is almost always a wide variation in how the team members weight the challenges, I suggest that the team come up with an average weighting as shown in the right hand column of Table 1.

Challenge Team Member A Team Member B Average
Improving app performance 25 55 40
Increase availability 25 25 25
Reduce cost 25 15 20
Increase security 25 5 15

Table 1: Sample Weighting

If at all possible I recommend that the team review both the WAN challenges they have identified and their weighting with the appropriate managers. For example, in one recent network design project that I was involved with we used the process described above to come up with a set of weighted challenges that we reviewed with the VP of infrastructure. His feedback was that his boss the CIO was very concerned that the whole IT organization needed to pay more attention to security. As part of that conversation with the infrastructure VP, we modified the weight that we had given to security.

Rate Alternative Solutions

Once the team has come up with a set of weights for the key WAN challenges, it should use those weights to rate alternative solutions. For the sake of example, assume there are two viable alternative WAN designs, one from Vendor A and the other from Vendor B.

Challenge Weighting Vendor A Scores Vendor A Total Vendor B Scores Vendor B Total
Improving app performance 40 9 360 7 280
Increase availability 25 8 200 8 200
Reduce cost 20 7 140 8 160
Increase security 15 7 105 6 90
Grand Total 805 730

Table 2: Evaluating Vendors

As shown in Table 2, the team used a 10 point scale to evaluate how the two solutions responded to each of the WAN challenges. The fourth column from the left demonstrates how the total score for vendor A was determined. The team gave Vendor A a 9 for improving app performance. That 9 was multiplied by the weight of that challenge (40) to arrive at a score of 360. That process was repeated for each challenge and the sum of the four scores (805) was determined. That process was also applied to Vendor B, whose total score of 730 is significantly lower than Vendor A’s total score. If the scores were closer, it might be valuable to do a “what-if” analysis. For example, what-if reducing cost was weighted higher than 20? What-if Vendor B got an 8 for improving app performance?

When the team presents their vendor evaluation to management there should be little if any discussion of either the set of WAN challenges or the weights that were used in the evaluation as those items should already have been reviewed with management and adjusted based on their feedback. This limits the discussion with management to a small set of well-defined, well-confined questions such as why vendor A got a 9 for improving app performance and vendor B got a 7. In most cases, management, particularly senior management, won’t spend much time on questions like that.

While this process doesn’t guarantee management buy-in, it does minimize the probability of protracted discussions and the likelihood of the team having to repeat parts of the evaluation process. In my next blog I discuss some other key steps that a company can take to go from their current WAN design to a next generation design.

About the author
Jim Metzler
Jim has a broad background in the IT industry. This includes serving as a software engineer, an engineering manager for high-speed data services for a major network service provider, a product manager for network hardware, a network manager at two Fortune 500 companies, and the principal of a consulting organization. In addition, Jim has created software tools for designing customer networks for a major network service provider and directed and performed market research at a major industry analyst firm. Jim’s current interests include both cloud networking and application and service delivery. Jim has a Ph.D. in Mathematics from Boston University.