Hi @BenVdP

See these resources

https://docs.microsoft.com/en-gb/microsoftteams/network-planner
https://docs.microsoft.com/en-us/microsoftteams/tutorial-network-planner-example

Think of the persona as a type of user in your organisation. The persona has permission to do the following - make audio calls, make video calls, screen share etc. You would create a persona of what a typical person does and then put a number against that persona (I.e. 30 users fit this persona) to work out the bandwidth required.

For example

Persona 1 - 20 users - use Audio/Video/Screen sharing but not conferencing
Persona 2 - 15 users - use Audio/Video/Screen Sharing/Conferencing
Persona 3 - 5 users - all

You maybe just have one persona - many small businesses typically have one persona who have access to everything

Hope that makes sense and helps you to build your network plan

Best, Chris
www.000webhost.com