: ATM virtual path (VP) contains bundles of virtual channels (VCs). A VP layer network can be used as a server layer network of VC layer networks and each VC layer network can be a client layer. Therefore the effective provision of VC services can be achieved by a better routing scheme of the VP layer network. However, the traditional hierarchical routing scheme of PNNI signaling protocol does not provide the globally optimal route in hierarchical transport network due to its successive network ning and topology abstraction. We propose a new VP routing scheme suitable for a nation-wide hierarchical transport network and a network model suitable for the scalable VP network management system. The routing algorithm can provide the globally optimal route in the hierarchical network environment from the perspectives of maximization of network resource utilization and satisfaction of the end user's QoS requirement. In addition, we describe the implementation model of the ATM virtual pat...