350-401 Question 64
Select 3A network administrator is implementing Quality of Service (QoS) on a WAN link with limited bandwidth. The goal is to prioritize VoIP traffic while ensuring that critical business applications also receive sufficient bandwidth. Which QoS components should be configured to achieve this objective?
- A
Classification
- B
Congestion Avoidance
- C
Queuing
- D
Traffic Shaping
- E
Policing
Show answer and explanation
Correct answers: A, C, D
Explanation
To achieve QoS objectives on a constrained WAN link, Classification is required to identify traffic types. Queuing ensures that high-priority traffic like VoIP is prioritized during congestion, while Traffic Shaping helps control the rate of outbound traffic to match the WAN link's capacity. Congestion Avoidance and Policing are less relevant in this scenario as they do not directly address prioritization or bandwidth allocation for critical traffic.
- A. Correct.
Classification is essential to identify and mark traffic based on its type (e.g., VoIP, business applications). This allows the network to treat different types of traffic according to their importance.
- B. Incorrect.
Congestion Avoidance is used to prevent buffer overflows by dropping lower-priority packets under high traffic conditions. However, in this scenario, prioritizing traffic is the goal, not just preventing congestion.
- C. Correct.
Queuing is critical for prioritizing certain types of traffic (e.g., VoIP) over others during times of congestion. This ensures that high-priority traffic is forwarded first.
- D. Correct.
Traffic Shaping smoothens traffic flows by controlling the rate of outbound traffic. This is essential on a WAN link with limited bandwidth to ensure that traffic matches the capacity of the link.
- E. Incorrect.
Policing is used to enforce traffic rate limits by dropping or remarking excess traffic. While this can control bandwidth usage, it does not prioritize traffic or ensure sufficient bandwidth allocation for critical traffic types.