Hi John, I have attempted to summarize the problem as you see it in the attached diagram. My understanding is that you want a network model that will support option 3 in the attached diagram. This will allow a port to be assigned to a link in a network without requiring a connection that forwards to a physical port on a switch to be present. Is this correct? Guy ------------------------------------------------------------------------------------------------------------------ Guy Roberts, Ph.D Network Engineering & Planning DANTE - www.dante.net<http://www.dante.net/> Tel: +44 (0)1223 371 316 City House, 126-130 Hills Road Cambridge, CB2 1PQ, UK ------------------------------------------------------------------------------------------------------------------