A method for determining beginning and end nodes in a FALSP, applied to a multilayer network using an higher-layer signaling triggering model to establish the FALSP is provided, comprising: a path compute element, when a computed service path comprises FALSPs of one or more layers, encapsulating FALSP path information of each layer into a Secondary Explicit Route Object (SERO) respectively to return together with service path information through inquiry response message to a beginning node in a first layer initiating the inquiry; after receiving them, a node in the service path determining whether the node is a beginning node in the FALSP of a layer according to said FALSP path information, if yes, learning that the FALSP is the FALSP of next layer, and determining an end node in the FALSP of the next layer according to FALSP path information of the next layer. A multilayer network is also provided.