A position in which an optical signal characteristic is compensated in an optical network can be chosen. An optical network equipment measures an optical signal characteristic for each wavelength, and notifies an optical network equipment on a communication path of an optical signal characteristic index and control necessity determination threshold. In an upstream portion of the communication path, the optical network equipment (a start point or the like of the communication path) that can compensate the optical signal characteristic for each wavelength determines the necessity to eliminate a deviation between wavelengths and the position to eliminate it, using the optical signal characteristic index and the control necessity determination threshold. The equipment determines a compensator to be controlled, and a compensation amount, based on the result, and commands an optical network equipment including the compensator to control the compensator, using a communication path establishment control protocol such as GMPLS-extended RSVP-TE.