- ✓Effective network planning starts with a thorough understanding of the organisation's current and anticipated data traffic, security requirements, and budget constraints.
- ✓Network design documentation typically includes both logical diagrams, showing how devices and systems relate, and physical diagrams, showing where equipment is located.
- ✓Redundancy planning ensures that critical network paths have backup routes to maintain connectivity if a primary link fails.
- ✓Scalability must be considered from the outset; a network that meets today's needs but cannot grow with the organisation will require costly redesign.
- ✓Vendor selection decisions for network hardware and software should be driven by technical requirements, support quality, and total cost of ownership.
Listen to the full episode inside the course. Enrol to access all 80 episodes, plus assignments, tutor support and Student Finance funding.
Start learning →Alex: Today we're looking at how to plan and design a managed network infrastructure at the Level 5 HND standard. Sam, what distinguishes a Level 5 approach to network planning from what we covered at Level 4?
Sam: At Level 4, we focused on understanding network design principles and applying them to create a functioning network. At Level 5, the expectation is that you can engage with more complex requirements, make and justify sophisticated architectural decisions, consider the operational management implications of design choices, and produce professional-quality design documentation. It's the difference between following a design recipe and genuinely engineering a solution.
Alex: Where does the planning process start at this level?
Sam: With a thorough requirements analysis. At Level 5 you're expected to engage critically with requirements rather than just accepting them as given. This means asking probing questions: Is the stated bandwidth requirement based on actual measurement or estimation? What are the consequences of a one-hour network outage? What growth is projected over the next three years? Are there regulatory requirements that affect how the network must be designed? This critical engagement with requirements is what produces designs that actually serve the organisation's needs.
Alex: How do redundancy and resilience factor into the design?
Sam: They're central. At Level 5, you're designing for organisations where network availability is genuinely business-critical. This means dual uplinks from access switches to distribution switches, redundant distribution switches with failover protocols like HSRP or VRRP, multiple paths from the campus network to the internet using different service providers, and possibly geographically separated data centre connectivity for disaster recovery. Every element of the critical path needs a failover mechanism.
Alex: How do you document the design for a professional audience?
Sam: A professional network design document includes a requirements summary, an architecture overview, a logical topology diagram showing the logical structure of the network including IP addressing, VLAN design, and routing, a physical topology diagram showing where equipment is physically located, a bill of materials listing all equipment required, configuration specifications for key devices, and a risk register identifying design risks and mitigations. The document should be detailed enough that a competent network engineer could implement the design from it.
Alex: What about the management aspects of the design? It's a network management unit after all.
Sam: The design should explicitly address how the network will be managed: what monitoring platform will be used, how alerts will be handled, what the change management process will be, how configurations will be backed up, what the maintenance windows will be, and how the network will be documented and kept documented as it evolves. Managability is a design requirement, not an afterthought.
Alex: Brilliant. Thanks Sam. Next we look at the practical work of configuring network systems.