HCoS: 3-level hierarchical scheduling

You can configure many different three-level scheduling hierarchies, depending on the location of the interface set and the use of underlying interfaces. In all variations, the physical interface is a level 1 CoS scheduler node and the queues reside at level 4. When you use three-level hierarchical scheduling, interface sets can reside at either level 2 or level 3. You can also configure an underlying logic interface at level 2 and a logical interface at level 3.