Final answer:
Traffic shaping, Policing, and Weighted Fair Queuing (WFQ) are congestion management tools in QoS.
Random Early Detection (RED) is a congestion avoidance mechanism and not a congestion management tool.
Therefore, the correct options are: a) Traffic shaping b) Policing and d) Weighted Fair Queuing (WFQ).
Step-by-step explanation:
Among the options listed, all are considered tools for congestion management in the realm of Quality of Service (QoS), except for Random Early Detection (RED), which is a congestion avoidance mechanism.
The mechanisms used for congestion management in QoS include:
- Traffic shaping: This delays some data to bring traffic into compliance with the desired traffic profile.
- Policing: This drops packets or applies a lower priority to them when the traffic exceeds a specified rate.
- Weighted Fair Queuing (WFQ): This provides fair bandwidth distribution among different streams of traffic.
Therefore, options a) Traffic shaping, b) Policing, and d) Weighted Fair Queuing (WFQ) are the correct answers as they are directly involved in managing congestion.