An FDDI Station PHY Port entity provides the management view of the FDDI
   Station PHY Port and the FDDI pmd.  Each station has at least one PHY port
   and a concentrator is a device that has at least one phy port of type M.
   A dual-attached station or dual-attached concentrator has a phy port type
   A and type B.  A single-attached station has a phy port of type B.