In my company there are strict firewall rules. Because of that I can only allow a small range of ports for using NGO. With the Unity Transport Script random (ephemeral) ports are used for the client. Since clients use ephemeral ports by default it is not possible to work with a small range of ports. It would be nice to have the possibility to select specific ports or just one port for that case.
I had a ticket open regarding this topic and it was recommended to open a feature request.