Description: VDSL2 specific subcarriers mask. This configuration parameter defines the restrictions, additional to the band plan, to determine the set of subcarriers allowed for transmission in both upstream and downstream directions. The parameter shall describe the not masked subcarriers as one or more frequency bands. Each band is represented by start and stop subcarrier indices with a subcarrier spacing of 4.3125kHz. The valid range of subcarrier indices runs from 0 to at least the index of the highest allowed subcarrier in both transmission directions among all profiles enabled by the parameter hwVOPLineSpectrumConfProfProfiles. Up to 32 bands may be specified. Other subcarriers shall be masked.