Before you design any network, what do you ask?
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Say this first
Business first, then technical, then constraints. Who uses it and how many, which applications matter and where they live, how much downtime is acceptable and what it costs, growth plans, security and compliance needs, budget and timeline, and who will run it. Every design decision should trace back to one of those answers, and anything unknown becomes a stated assumption.
Go deeper
Business
- What does the business do here, and which services must never stop?
- Headcount now and in three years? New sites, hybrid work, acquisitions?
- What does an hour of outage cost, and who decides on risk?
Technical
- Applications: SaaS, on-premises, data center or cloud? Voice and video? Latency-sensitive systems?
- Devices: laptops, phones, IoT, cameras, production equipment. How many need PoE?
- Availability target per service, and security or compliance rules (card payments, health data, segmentation requirements).
Constraints
- Budget for capital and running costs, timeline, existing equipment and contracts.
- The building: floors, closets, cabling, power. Which carriers serve the address.
- The team: skills, size, vendor preference, managed service or in-house.
In an interview
Ask three or four sharp questions, then say "I will assume the following; tell me if any are wrong" and continue. Interviewers grade the structure as much as the final design.
Traps
- Jumping straight to switch models and protocols. It reads as someone who builds before understanding.
How did you do?Book 1.2 Requirements