300-420 Question 259
Single answerA financial services company has implemented QoS on its enterprise network to prioritize critical application traffic. During a review of their queuing strategy, they notice that voice traffic is experiencing delays despite being marked as high priority. Which queuing method would most effectively ensure minimal delay for voice traffic?
- A
Weighted Fair Queuing (WFQ)
- B
Class-Based Weighted Fair Queuing (CBWFQ)
- C
Low Latency Queuing (LLQ)
- D
First-In, First-Out (FIFO)
Show answer and explanation
Correct answer: C
Explanation
Low Latency Queuing (LLQ) is the optimal solution when dealing with delay-sensitive traffic such as voice. It combines strict priority queuing for critical traffic while still allowing other traffic to be managed using class-based queuing, ensuring both fairness and the lowest possible latency for high-priority applications.
- A. Incorrect.
Weighted Fair Queuing (WFQ) provides fair bandwidth allocation for different traffic flows but does not guarantee real-time priority for delay-sensitive traffic like voice.
- B. Incorrect.
Class-Based Weighted Fair Queuing (CBWFQ) allows you to define classes and allocate bandwidth, but without strict priority, voice traffic may still experience delays when competing with other traffic.
- C. Correct.
Low Latency Queuing (LLQ) combines CBWFQ with strict priority queuing for high-priority traffic, ensuring that voice traffic is expedited and experiences minimal delay, making it the best choice for this scenario.
- D. Incorrect.
First-In, First-Out (FIFO) processes packets in the order they arrive without differentiation, making it unsuitable for prioritizing delay-sensitive traffic like voice.