Are there any conventions that can be followed to number the ports for entities. (either XMLFW or WSProxy or MPG)

If within a box, if different environments (Development, testing and QA) are present as differnt domains, how are we supposed to assign port numbers.

I understand the port numbers may range between 0000 to 9999 even across the domains. So as we move our objects across environments as the project progresses wont it be a rework to renumber ports once we move objects to different domains (environments).

or Do we need to go for separate boxes for different environments?