300-420 Question 246
Select 2A company is deploying a new video conferencing system across its enterprise network. The IT team needs to ensure that the video traffic is prioritized over less critical traffic, such as file transfers, while ensuring voice traffic experiences minimal latency. Which two design considerations should the team include in their end-to-end QoS policy to achieve this requirement?
- A
Implement Low-Latency Queuing (LLQ) to prioritize voice traffic.
- B
Mark video traffic with DSCP value AF41 to provide assured forwarding.
- C
Configure Weighted Fair Queuing (WFQ) for all traffic classes to ensure equal bandwidth allocation.
- D
Apply a strict priority queue for all video and voice traffic to ensure zero packet loss.
- E
Use traffic policing to limit video traffic to a specific bandwidth threshold.
Show answer and explanation
Correct answers: A, B
Explanation
In designing end-to-end QoS policies, it is critical to prioritize real-time traffic like voice and video appropriately. LLQ is used to prioritize voice traffic and ensure minimal latency, while marking video traffic with DSCP AF41 provides it with assured forwarding treatment. This combination ensures voice traffic is protected while video traffic is handled with high priority without starving other traffic classes.
- A. Correct.
Low-Latency Queuing (LLQ) is essential for voice traffic as it minimizes latency and jitter, ensuring real-time traffic is prioritized appropriately.
- B. Correct.
Marking video traffic with DSCP AF41 ensures it receives assured forwarding treatment, which helps differentiate video traffic from other data traffic without compromising voice traffic.
- C. Incorrect.
Weighted Fair Queuing (WFQ) treats all traffic classes more equally, which would not prioritize video or voice traffic over less critical traffic like file transfers.
- D. Incorrect.
A strict priority queue for both video and voice traffic can lead to starvation of other traffic classes, which is not recommended in enterprise QoS design.
- E. Incorrect.
Traffic policing for video traffic would limit its bandwidth but does not prioritize it, potentially disrupting the quality of the video conferencing system.