350-401 Question 67
Single answerA network administrator is tasked with implementing a QoS policy to prioritize voice traffic over other types of traffic on a WAN link with limited bandwidth. The administrator wants to ensure that voice packets are queued and forwarded with minimal delay. Which QoS mechanism should the administrator configure as part of the policy?
- A
Weighted Fair Queueing (WFQ)
- B
Class-Based Weighted Fair Queueing (CBWFQ)
- C
Low Latency Queueing (LLQ)
- D
Traffic Policing
Show answer and explanation
Correct answer: C
Explanation
Low Latency Queueing (LLQ) is the appropriate mechanism to prioritize voice traffic because it ensures that latency-sensitive traffic is placed in a strict priority queue, minimizing delay and jitter. This is critical for maintaining voice quality over a WAN link with limited bandwidth. Other options like WFQ and CBWFQ provide fair or custom bandwidth allocation but do not address the need for minimal delay. Traffic policing, on the other hand, enforces rate limits without prioritizing traffic.
- A. Incorrect.
WFQ provides fair bandwidth allocation among flows but does not guarantee low latency for specific traffic types like voice.
- B. Incorrect.
CBWFQ allows custom bandwidth allocations to traffic classes but does not inherently include mechanisms to minimize delay for latency-sensitive traffic.
- C. Correct.
LLQ is specifically designed to provide low-latency handling for traffic such as voice by combining strict priority queueing with CBWFQ.
- D. Incorrect.
Traffic policing limits traffic rates but does not prioritize or reduce delay for specific traffic types.