Controls the default QoS class, i.e., the QoS class for frames not classified in any way. There is a one to one mapping between QoS class, queue and priority. A QoS class of 0 (zero) has the lowest priority. NOTe: If the QoS class has been dynamically changed, then the actual QoS class is shown in parentheses after the configured QoS class. range: 0~7, default: 0.