Patent ID: 8422360

Claim:
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 method comprising: performed by the server, a connection request receiving step for receiving from one of the user node apparatuses a connection request for connecting to the core network, a route calculation step, in response to this connection request, for confirming available resources in the path information and calculating a route for the working path and a route for the backup path based on the path information, and a high-reliability-path requesting step for sending the boundary node apparatus the calculated routes for the working path and for the backup path along with an establishment request for establishing the working path; performed by the boundary node apparatus, a working path establishing step, in response to a working-path-establishment request, for establishing the working path calculated by the server between the boundary node apparatuses via relay node apparatuses that relay the core network, and a failure detection step for detecting a failure in the core network; when a failure is detected in the core network, performed by the boundary node apparatus, a backup path establishment step, based on the route for the backup path calculated by the server, for establishing the backup path between the boundary node apparatuses via the relay node apparatuses, a path switching step for switching over the working path to the backup path established, and a backup-path-establishment sending step for sending the server the route for the backup path switched over from the working path; and performed by the server, a backup path establishment receiving step for receiving the route for the backup path switched over from the working path by the boundary node apparatus, and a path information updating step for updating the path information based on the route for the backup path switched over from the working path by the boundary node apparatus.