Business Requirements in the Network Design Process with Daniel Dib

In the previous blog my colleague Emanuel Lipschütz explained how a network designer can work with a structured process in order to create good network designs that serve the business best.


In this blog I will describe how the first meeting with the customer can take place and give examples of questions that could be relevant to ask to find out about the business, where it is heading and what is most important to the business.



In the CCDE practical exam, 36% of the exam consists of analyzing requirements so it’s a very important skill to have. I have noticed that many people have a strong technical background but struggle in the analyzing section of the exam. If you score low in that section it’s likely that the rest of the exam will be tough since you might be acting on the wrong information.


The best way to improve your business skills is to put you in a position where you meet customers, interact with CXO level people and colleagues in sales and presales. This might be challenging to begin with but you will get more comfortable when you’ve had some exposure to this side of network design.


When a business opportunity has been identified a meeting is setup with the customer. This meeting is often in form of a workshop where the representatives from the customer is often the CTO, CIO and experienced engineers. The goal of the meeting is to gather the business requirements but sometimes I will also give a presentation on different technologies which might be suitable for the project. It’s important that you can communicate both with the business side and the technical side. Before I can start working on a design I must understand what their business is about, where they are heading, what the drivers and requirements are. Here are some typical questions with a description why I like to ask them.


The questions will tell me about the business but then I also want to find out how they function as an organization.


1. What are they key drivers for IT in your organization today?

Here I’m looking to identify where the business is going. Are they looking to move applications to the cloud? Do they need more mobility for their employees? Are they interested in a Bring Your Own Device (BYOD) solution? Are they struggling with network security?


2. Are you expecting to grow the business within the next few years?

I want to find out how much the solution will need to scale. The size of the company could rapidly increase through an acquisition or merger. It’s also possible that the business might decrease in size through a divestiture.


3. What’s the implication to your business when the network is not reachable?

I’m trying to gauge the importance of the network to the organization. Is there a loss of revenue or any intangible loss? Some organizations can survive a few minutes while the network reconverges while others need convergence in the range of a second.


4. Are they restricted by any regulatory constraints such as PCI-DSS?

If I need to design to meet compliance requirements, I want to find out from the start and not when the design is close to being finished.


The questions below will tell me about the user applications and where the users access them from.


1. What are the most important applications/systems in use today?

I want to find out what applications are critical to the business. What applications are they running? Do their applications require a Layer 2 adjacency? Are they using any clusters?


2. What are your most mission critical offices?

Redundancy and resiliency will be important in the offices in which the company cannot afford to have any downtime and is critical to their operation. Larger offices are not the only offices that may be important, smaller production sites can be just as important.


3. Are any of your users regularly mobile or remotely working from home?

I want to find out if the network should be reachable from the outside and if there needs to be VPN connectivity to the offices.


I will then also ask them about their workflow and processes.


1. Does your organization use maintenance windows?

It’s important to understand how changes are handled and when the next window of opportunity exists to implement any changes. Does the new design have to go through a change advisory board (CAB) process?


2. Do you have any existing orchestration tools in place?

I determine if there are existing tools that can be leveraged to update the configuration(s). If so, the project may require less time to implement the changes versus if there are no tools available.


I am also interested in the technical requirements of course but do note that I’m only interested in those once I’ve already covered the business side.


1.What routing protocols are in use today?

If the organization is using one protocol today, it could make sense to use the existing one, but if I am looking to add a new protocol, it must add value somehow...


2. Do you have a need for IPv6?

It’s better to include IPv6 into the design from the beginning rather than adding it as a quick fix at the end.


3. Do you have applications that require multicast transport?

Multicast design can be complex and if it is a requirement, it should be covered straight away so that WAN transports etc. are multicast capable when the design is put into place.


During this time, you should do more listening than talking and be sure to take notes from the meeting. Try to understand where the business is going and let the customer explain their environment to you and what’s important to them. It’s your job to design based on their needs, not create the most technically brilliant solution.


After the workshop is done, I write down the requirements in a customer requirements document (CRD). This document will then be used as input for the high level design (HLD). It’s important to have the customer sign off on this document so that all of the requirements have been documented and agreed upon. Don’t be afraid to challenge the customer and to keep asking for information until you have all the information needed for the design.


Analyzing business and network requirements is an important skill both in the life of a network designer and in the CCDE practical exam. To be good in any of these roles you need to open your mind, analyze the requirements, find the best solution for the business and move forward with that solution. I hope to write more about the job of a network designer later on and wish you good luck in your studies!


About the Author

pic Daniel Dib.jpg


Daniel Dib, CCIE #37149, CCDE #20160011, is a Senior Network Architect at Conscia Netsafe. He works with creating scalable, modular and highly available network designs that meet business needs. Daniel started out in implementation and operations and got his CCIE in 2012. In May 2016 he became the second person in Sweden to get CCDE certified.

He often acts as a subject matter expert for his customers with deep expertise in routing, switching, multicast and fast convergence.



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