US Patent 7617302 Communication networks

A communications network comprises a plurality of ports modelled according to a layer protocol, and a network management system adapted to store information describing the physical and logical resources within the network, wherein the network management system is responsive to information describing connectivity in a first one of the layers to derive further information concerning connectivity in another of the layers. The first layer is preferably the closest known layer connectivity to the physical layer and the derived connectivity information applies to successive ones of the upper layers.