cVoaAttenuationControlMode 1.3.6.1.4.1.9.9.262.1.1.1.1.2

This object is used to set the mode of controlling the attenuation level of a VOA at an interface. When the mode is set to 'manual', the attenuation level is configured manually, by setting the desired attenuation level in the cVoaAttenuation object. The cVoaDesiredPower object does not apply in this case. When the mode is set to 'automatic', the attenuation level is continuously adjusted to maintain a desired power level, after attenuation. The desired optical power level after attenuation is configured using the cVoaDesiredPower object. The cVoaAttenuation object cannot be configured in this case, but it indicates the attenuation level derived from the desired power level. The automatic mode of controlling attenuation should not be used when the monitored power level includes multiple wavelengths, since the power level monitor cannot distinguish between a decrease in power across all wavelengths, versus a loss of power of some but not all wavelengths. If some but not all wavelengths go down, this would cause the attenuation level to be automatically decreased, leading to an increase in the power level of the remaining wavelengths.