Patent ID: 8712235

Claim:
A transmission apparatus comprising: a memory; and a processor coupled to the memory, the processor being configured to: recognize a number of working failures and a number of protection failures between each pair of nodes in a network for transmission of wavelength-multiplexed signal light, the number of working failures being a number of failures in signal light in wavelengths along a working path between each pair of nodes and the number of protection failures being a number of failures in signal light in wavelengths along a protection path between each pair of nodes; when a working failure or a protection failure occurs at one or more wavelengths of the wavelength-multiplexed signal light between only one pair of nodes of the network, perform path switching between the working path and the protection path for the only one pair of nodes for all of the wavelengths of the wavelength-multiplexed signal light; and when a working failure or a protection failure occurs at one or more wavelengths of the wavelength-multiplexed signal light between more than one pair of nodes of the network, perform path switching between the working path and the protection path for only one pair of the more than one pair of nodes based on the recognized number of working failures and number of protection failures for each of the respective pair of nodes.