Patent ID: 8619246

Claim:
An optical node apparatus whose plural function units are connected to each other through an optical transmission line, the optical node apparatus comprising: a control unit which carries out a control to send an optical test signal and to stop sending the optical test signal; a sending unit which sends the optical test signal on a basis of an instruction issued by the control unit; a receiving unit which receives the optical test signal sent by the sending unit through the optical transmission line; a discriminating unit which discriminates whether the receiving unit receives the optical test signal; a sending light band coupler arranged on an optical path of the optical test signal; a receiving light band coupler arranged on another optical path of the optical test signal; and a loop back switch arranged between the sending light band coupler and the receiving light band coupler so that the discriminating unit specifies an abnormal point of the optical path based on the received optical test signal through the loop back switch.