This MIB object provides directive on the modulation or summation of the frequencies involved in the tone. It is to be noted that while summation can be done without any constraint on the number of frequencies, the modulation (amplitude) holds good only when there are two frequencies (first and second). Thus: - If the mode is set to a value of 'firstModulatedBySecond(1)', the first frequency MUST be modulated by the second, and the remaining frequencies (third and fourth) ignored. The percentage of amplitude modulation to be applied is defined by the MIB object pktcSigDevToneFreqAmpModePrtg. - If the mode is set to a value of 'summation(2)', all the frequencies MUST be summed without any modulation.