By definition, ports in ConnectMaster are assigned to a Network Interface / Card component. So when creating a Virtual sub-port, it is created as a child of another port on the same Network Element / Mux, and it must also be assigned to a  Network Interface on that Mux. The Network Interface / Card to which a Virtual sub-port is assigned is often a management card in the Network Element / Mux, but if appropriate it can be assigned to any of the cards in the Network Element / Mux.