An output port switching unit that connects to a first optical transmission path, a second optical transmission path, and the connection information processor, and sets a destination of the first optical transmission path as the connection information processor in an initial state. A controller that transmits transmission mode information indicating a transmission mode identified based on connection information of the first optical transmission path acquired from an optical signal transmitted by an optical transceiver provided in an optical communicator that the connection information processor connects to the first optical transmission path, connection request data included in the optical signal and transmitted by the optical transceiver, and transmission path information of the second optical transmission path to the optical transceiver through the first optical transmission path. The output port switching unit performs switching processing of switching a destination of the first optical transmission path from the connection information processor to the second optical transmission path after the controller transmits the transmission mode information.