Port forward rules limited to 9 ports

Update :::::::::::::::::::

If I don't need to assign a port forward for each camera.

But what port do I input in camera when it says port ?

In blue iris I took out the port #,
i can see the camera inside and outside network...
but the camera ip in blue iris defaults to port 80 in configuration ?

I set another cam the same way defaulting to port 80, it works also.

So - How many cameras can be on one port number ???