Physical switch selection is always an interesting question to ask when building your network. The term 'switch' in this context should be broadly interpreted as both L2 and L3 devices. In the SDN world, where we separate the control and data plane, any network function, such as routing, switching, firewall, monitoring, or firewall function, are software function while we reduce the physical packet transport into flows. The line between software-based versus hardware switch is almost non-existent when it comes to management and control plane constructs. However, we still need to be concerned with hardware capacity when it comes to building our network infrastructure.
If you draw a comparison between network engineering and systems engineering when purchasing servers, a system engineer would consider hardware specifications, such as CPU, memory...
