Which QoS mechanism enables creating multiple hierarchical levels of policy for finer-grained traffic management?

H-QoS (Hierarchical Quality of Service) allows you to apply QoS policies at multiple levels, such as a parent policy for an entire interface and child policies for specific traffic classes within that interface. This creates a hierarchical structure for finer-grained control over bandwidth, queuing, and other QoS parameters. Policing is a mechanism to limit the input or output rate of a class of traffic, but it doesn't create hierarchical levels. Congestion avoidance mechanisms like WRED prevent tail drops but don't define policy hierarchies. Dual Policy is not a standard QoS mechanism for hierarchical policy creation.