If I understand that correctly, it is like Art Net, a protocool that is made for the controllers to be ethernet based. That has more to it, since each controller box has to look, respond, etc. This is quite a bit simplier, the controllers are still straight DMX. Just a software program in between that and the serial port, looks at the an extra byte, selected the correct serial port based on universe to port assignment, and then sends the dmx packet.
Unless I am misunderstanding the protocool, and it is for something designed to be something not at the controller level.