This value gives the end label of a waveband Generalized Label's wavelength range, valid only when gmplsLabelSubtype is wavebandLabel(6). An engineer uses it along with gmplsWavebandStartLabel to define the upper boundary of the contiguous wavelength range that makes up a waveband. For example, a gmplsWavebandEndLabel of 20 paired with a start label of 10 would define a waveband spanning wavelength labels 10 through 20.