The communication network system

In an MPLS/GMPLS network, a link used by a communication path for each hop and adaptations used at the boundary between management domains or layers are appropriately and automatically selected according to a service type and a required maintenance condition, without making a control sequence complicated. First, a unit for requesting path establishment by including an identifier of a service to be provided and a service attribute in a communication path establishment control message is provided for a source node. Second, a unit for determining a required maintenance condition for a communication path and adaptations according to the service identifier and/or the service attribute is provided for each node. Third, links and nodes through which the communication path passes are determined by comparing each of achievable maintenance conditions for network resources with the required maintenance condition. The determined links, nodes, adaptations are specified as operation parameters in switches and/or interfaces.