300-415 Question 259
Single answerA network engineer is configuring QoS policies on a Cisco SD-WAN solution to manage traffic for a financial institution. The engineer needs to ensure that critical financial transactions receive the highest priority during congestion, while bulk data transfers are deprioritized. Which queuing mechanism should the engineer use to achieve this?
- A
Priority Queuing (PQ)
- B
Weighted Round Robin (WRR)
- C
Class-Based Weighted Fair Queuing (CBWFQ)
- D
First-In-First-Out (FIFO)
Show answer and explanation
Correct answer: A
Explanation
Priority Queuing (PQ) is the optimal choice when critical traffic, such as financial transactions, must always be prioritized and processed immediately during congestion. Other queuing mechanisms, such as WRR or CBWFQ, may provide fair handling of traffic but do not guarantee the absolute prioritization needed for such critical use cases.
- A. Correct.
Priority Queuing (PQ) ensures that high-priority traffic, such as critical financial transactions, is processed immediately, even during congestion. It is the most suitable option for this scenario.
- B. Incorrect.
Weighted Round Robin (WRR) assigns weights to traffic classes but does not guarantee absolute priority for critical traffic. Thus, it would not be ideal for prioritizing financial transactions during congestion.
- C. Incorrect.
Class-Based Weighted Fair Queuing (CBWFQ) provides fair bandwidth allocation among traffic classes but does not ensure absolute priority for critical traffic during congestion.
- D. Incorrect.
First-In-First-Out (FIFO) processes packets in the order they arrive without prioritization, making it unsuitable for prioritizing critical traffic.