What is a network diagram?

Put simply, a network diagram is a visual representation of a computer or telecommunications network. At the very least, it shows the components (or nodes) that make up the network (for example routers and switches), and the connections between them. The diagram may also show groupings of nodes (for example, by geographic region).

More than 80% of us are visual thinkers (we relate better to seeing visual representations rather than textual or verbal descriptions, especially for highly conceptual topics). If you're a network architect or developer working on a large project, you may have stakeholders or a team that needs to understand the landscape of your network infrastructure, and a visual representation can help simplify that knowledge and make it more digestible.

A network's topology refers to the layout used, and the topology you use to represent your network can be either physical or logical. Cases where it's more appropriate to use a physical network topology may include an office floorplan where it's useful to display nodes as they would appear in their physical locations. A logical network topology, however, focusses on representing the grouping and relationships between nodes, but does not necessarily mirror their physical layout.

If you decide to create a network diagram, make sure to keep in mind what your goal is, as well as your audience's level of technical knowledge. Showing your entire network when you just need to focus on one specific area can be distracting, and you risk overloading your audience. It's important to tailor your diagram to the context of the discussion. For example, if you are planning for growth, the diagram may need to show where more equipment needs to be added, or if you are focussing on performance, you may need to highlight bottlenecking areas in your diagram with performance metrics overlaid.