Wavelength Spacing cannot be modified while Admin State is enabled. Wavelength Spacing cannot be modified in the same operation as Wavelength, Frequencey, and Channel, only one of those fields may be modified in a single operation. Wavelength Spacing cannot be provisioned when System Band Plan field is set to a value other than None, Wavelength Space field will also be automatically set to Flex Grid. When PTP Wavelength Spacing is changed from FlexGrid to a fixed grid (e.g. 50GHz), or from a fixed grid to another fixed grid value, if existing Wavelength and Frequency is not valid in the selected grid, their values will be set to zero. When PTP Wavelength Spacing is changed from a fixed grid (e.g. 50GHz) to FlexGrid, existing Wavelength, Frequency and Line System Channel Number remain unchanged.