The number of inputs and outputs varies dramatically.
The type of signals transported - switched can be analogue - Analog - audio signals or Digital.
Digital audio usually is in the AES/EBU standard for broadcast use.
Broadband routers can route more than one signal type e.g. analogue or more than one type of digital.
Because any of the inputs can be routed to any output, the internal arrangement of the router is arranged as a number of crosspoints which can be activated to pass the corresponding signal to the desired output.