Abstract: An NMS (10), which is a management apparatus connected to a plurality of NEs (1) forming a network so that the NMS (10) can communicate with the plurality of NEs (1), includes: an update information transmission unit (101) that transmits update information for an update process to the plurality of NEs (1), the update process requiring a suspension of communication; and an update time transmission unit (102) that transmits an update time to the plurality of NEs (1) after the plurality of NEs (1) receive the update information, the update time being a time at which the update process is performed. It is thereby possible to shorten the update times of the communication apparatuses in the network.

Abstract: An optical transmission system 100 includes a plurality of transmission devices 110 to 150 each configured to be capable of transmitting and receiving an optical signal at each of a plurality of different wavelengths and thereby transmitting and receiving a plurality of optical signals simultaneously. The transmission device 120 transmits an optical signal received at a transmission wavelength to each of the transmission device 130 and the transmission device 140. The optical transmission system transmits the optical signal at the transmission wavelength from the transmission device 110 to the transmission device 150 via each of a plurality of paths that partly overlap. The optical transmission system estimates, for each of the paths, a line quality representing the degree of coincidence between an optical signal transmitted by the transmission device 110 and an optical signal received by the transmission device 150.