Specifies either the upper limit on the throughput of the queue as a
percentage of the throughput of each output port on which the service
class is implemented. If zero, there is no maximum rate.
This field can not be set by the user
if rlDiffservModeEnabled = disabled and
rlPolicyServiceClassPriority = 0 or
rlDiffservModeEnabled = enabled and
rlPolicyServiceClassPhbType != expeditedForwarding or
rlBoundedPriorityQueueSupport = notSupported.