| 摘要 |
PROBLEM TO BE SOLVED: To highly accurately locate a point of failure having occurred in an optical network system in which transmission devices are interconnected by optical fiber cable.SOLUTION: A monitoring device 4 which is connected with transmission devices 1 via a monitoring network, comprises: an information transmission unit 41 which receives optical reception levels that are measured values of optical levels in optical reception units of optical signals in the respective transmission devices 1, from the respective transmission devices 1 via the monitoring network; and an abnormality point determination unit 42 which determines whether each of the respective optical reception levels of the transmission devices 1 is a normal value or an abnormal value, when the optical reception levels of two transmission devices are abnormal values, determines that the abnormality is failure in optical fiber cable, and when the optical reception level of one transmission device is an abnormal value, determines that the abnormality is failure in the optical reception unit in the transmission device 1 having the abnormal value. |
