CCDE: Book of Questions

What questions should network designers ask?


I’ve heard time and time again that “great network designers ask their customers a lot of questions to elicit requirements the customers know they need, and also to uncover requirements they don’t even know they need”. A friend of mine said there’s no such thing as a book of questions that network designers could use to help them better understand the customer’s network design needs. This stuck with me. If this is such an important trait of network designers, why isn’t there such a book? Shouldn’t there at least be a compilation of some of the most common questions network designers ask customers at the onset of a new design project to improve their knowledge?


My friend and CCDE/Triple CCIE Andre Laurent posed a question on his LinkedIn and Twitter accounts and had a great turn around. He received great insight shared by the community. Andre said that there seems to be three common themes: “starting with questions leading to discovery around business objectives, pain points, desired benefits, current state business capabilities, perceived constraints. Then diving into the application footprint and supporting infrastructure, policy, method of access and traffic patterns”. Below is the fully compiled list of the answers Andre received from his readers.  This isn’t meant to be an all-comprehensive list, but I think it’s a great start.


And to give credit where credit is due, thanks to all who replied to Andre’s ask (in alphabetical order): Andre Laurent, Darby Weaver, Dawit Kebede, Ellen Rayz, Evelyn Zafftadding, Hamed Zolghadri, Harindha Fernando, Haroon Aslam, Houman Asefi, Jason Bulpin, Jason Gooley, Jay Etchings, Jeff Boyd, Joel Thom, Jonathan Rigsbee, Joseph Brunner, Kazuo Yamamoto, Luis Matos, Marcello Ishida, Nic Swart, Orhan Ergun, Shaun Muller, Travis Newshott, Virgilio Spaziani, Youssef El-Metainy and Yuri Lukin.



Listed are some of the initial questions to ask your customers at the onset of a new network design project


1. Business objectives, pain points and perceived constraints

  • Who are the key stakeholders, sponsors, end users?
  • Why is there a project in the first place? What are the drivers for the redesign of your existing network?
  • What are the current pain points?
  • Which business outcomes the customer expects to achieve?
  • What is the business growth plan 3-5 years, capacity planning, scaling requirements?
  • Are there any regulatory constraints such as HIPAA, PCI, Fed, and Local Government that affect the organization and industry? Other known constraints?
  • Is there specific equipment, vendors, or protocols preferred or are absolutely out of the question?
  • What are the implementation timelines and milestones?
  • What are the key success factors? Are there known barriers to success?
  • What is the customer tolerance to risk? Conservative or bleeding edge?


2. Desired characteristics and capabilities

  • What is the current state of the network (baseline), to compare after the implementation of the new design?
  • Are there any documentation available, features in use, versions, is standardization consistent?
  • What is the financial investment (cost/budget, cost-benefit analysis) x desired business, operational, and innovation outcomes, followed by a technical translation of these needs/goals to a technology environment?
  • What are the desired characteristics of the new network: redundancy/resiliency/convergence, speed, security, cost, application performance, simplicity, manageability, capabilities? Load balancing, load sharing?
  • Public, private or hybrid cloud?


3. Footprint, policies, method of access and traffic patterns

  • What is the geographical distribution, connectivity options/capabilities on the branches?
  • Where do the servers reside in the network, their known vulnerabilities and how the services align with the security policies?
  • What are the current and future traffic patterns, north-south, east-west, or both?
  • What are the current and future applications' requirements and tolerance to delay, packet drop, and jitter?
  • What is the company security, infrastructure policies? Do you have specific design/architecture principles to adhere to? Any project management methodology or tools? Network management?
  • What are the established SLA's if any, and the level of success achieved for these SLA's?
  • Does the network support the business, the network is the business, or both?
  • Are there best practices?
  • Will there be a test lab or group, a prototype, a development area?


Do you have other questions you ask on your network design engagements that are not listed here? Do you have ideas for my upcoming blogs? Add them to the comments field!


Elaine Lopes


Elaine Lopes is the CCDE and CCAr Certifications Program Manager and Team Lead for the CCIE program team, and she’s passionate about how lives can change for the better through education and certification.



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