Method and node apparatus switching optical transport ring network

A node device for an optical transfer ring network for transmitting optical transfer frame of the working and protection lines between a plurality of node devices plurality of optical transmission paths connected to the ring at each light transmission path, failure of an optical transmission path during generation, the optical transfer comprising a control information transmitting means for transmitting an optical transfer frame including control information switching node apparatus of the counterpart in the optical transmission path failure as a destination, the switching control information to the transmission destination node device receiving a frame, having a switching means switching from said plurality of working lines to form a loop-back folding the transmission path between the optical transmission path in the protection line.