Slave station device, master station device, optical communication system, and malfunction detection method

Abstract

An ONU receiving an optical signal from an OLT including PON controllers includes: an optical receiver to convert, into an electric signal, an optical signal having a single optical wavelength set out of plural optical wavelengths; and a control frame extractor to extract and hold wavelength correspondence information indicating correspondence between MAC addresses of the PON controllers received from the OLT and the optical wavelengths. The control frame extractor, when receiving a wavelength switching request, extracts the optical wavelength after wavelength switching instructed in the wavelength switching request, obtains a setting address of the MAC address of the PON controller to which the ONU itself should be connected after the wavelength switching based on the extracted optical wavelength after the wavelength switching and the wavelength correspondence information, and determines whether a malfunction occurs based on a transmission source MAC address stored in a received control frame and the setting address.