Which component provides the hierarchical QoS structure for bandwidth control?

Which component provides the hierarchical QoS structure for bandwidth control?

• A. Queue Tree
• B. Traffic Shaper
• C. Bandwidth Manager
• D. QoS Policy

Answer: (A)

Hierarchical QoS is implemented with a queue tree, which creates a tree of queues with parent and child relationships to allocate bandwidth at multiple levels. The root queue defines the total available bandwidth, and child queues carve out portions for different services, users, or applications, each with its own limits, priorities, and scheduling rules. This structure lets you enforce both overall bandwidth and per-class guarantees in a layered, hierarchical way, which is the essence of hierarchical QoS. A traffic shaper can enforce a rate for individual flows or interfaces but doesn’t inherently build the multi-level tree structure used for hierarchical control. A bandwidth manager is more of a general term for tracking usage or applying quotas, but it doesn’t specify the hierarchical organization. A QoS policy defines rules and classes, but the actual hierarchical distribution of bandwidth is realized through the queue tree.

Hierarchical QoS is implemented with a queue tree, which creates a tree of queues with parent and child relationships to allocate bandwidth at multiple levels. The root queue defines the total available bandwidth, and child queues carve out portions for different services, users, or applications, each with its own limits, priorities, and scheduling rules. This structure lets you enforce both overall bandwidth and per-class guarantees in a layered, hierarchical way, which is the essence of hierarchical QoS.

A traffic shaper can enforce a rate for individual flows or interfaces but doesn’t inherently build the multi-level tree structure used for hierarchical control. A bandwidth manager is more of a general term for tracking usage or applying quotas, but it doesn’t specify the hierarchical organization. A QoS policy defines rules and classes, but the actual hierarchical distribution of bandwidth is realized through the queue tree.