The power classification as the index for the
statistics information for powered devices.
A value of 'cisco' indicates that the powered
devices are CISCO proprietary and their power
classification does not fall into any class
in IEEE specifications.
A value of 'class0' indicates that the power
classification of the powered devices falls into
class 0 in IEEE specifications.
A value of 'class1' indicates that the power
classification of the powered devices falls into
class 1 in IEEE specifications.
A value of 'class2' indicates that the power
classification of the powered devices falls into
class 2 in IEEE specifications.
A value of 'class3' indicates that the power
classification of the powered devices falls into
class 3 in IEEE specifications.
A value of 'class4' indicates that the power
classification of the powered devices falls into
class 4 in IEEE specifications.