A route switching method for switching a route in a core network that accommodates service networks including user node apparatuses by use of a server storing path information that includes, in every time frame, a route for a working path and a route for a backup path to be switched over from the working path, both of the working path and the backup path established between two boundary node apparatuses each of which is located on a boundary between the service network and the core network. The server calculates, in response to the connection request from the user node apparatus, a route for a working path and a route for a backup path, and requests the boundary node apparatus to establish this working path. The server can send the route for the backup path to the boundary node apparatus before a failure occurs in the core network. The boundary node apparatus establishes the working path in response to the establishment request for establishing the working path from the server, and can perform a quick recovery by switching over the working path to the backup path when a failure occurs in the core network.