Abstract: A resource state monitoring method, device and communication network are provided. The method includes: acquiring network event state information of a node in a network running process, detecting a data plane resource state of the node and a control plane resource state of the node when it determines that the network event state information of the node meets a resource state detection triggering condition, and reporting a detection result to a management plane of the node. The device includes an acquiring unit, a checking unit, a triggering unit, a detecting unit and a reporting unit. The network includes several nodes, a communication control device and a resource state monitoring device.

Abstract: A method for realizing service protection in the automatically switched optical network includes following steps: after any defect occurs on the working paths that carry the service, the first node and the last node of the working paths sends the requests to restore the paths setup in opposite directions, respectively; at least one intermediate node in the restoration path establishes a connection according to the restoration path setup request, and forwards the restoration path setup request hop by hop, until the setup of the recovering path is finished; the service is switched from the working paths to the restoration paths. A system for realizing service protection and a node device in an ASON is also provided. The paths restoration process can be faster obviously using this invention, and the restoration time can be shortened, and the work efficiency and reliability can be improved, and the service can be ensured to be restored.