Which one of the following QoS mechanisms is recommended for VoIP networks?

Which one of the following QoS mechanisms is recommended for VoIP networks?

A.
Low-latency queuing (LLQ)

B.
Switched-based queuing

C.
Fast queuing

D.
Custom queuing

Explanation:
Explanation

Low-Latency Queuing
Low-latency queuing (LLQ) adds a strict priority queue (PQ) to CBWFQ. The strict PQ allows delay sensitive traffic such as voice to be sent first, before other queues are serviced. That gives voice preferential treatment over the other traffic types. Unlike priority queuing, LLQ provides for a maximum threshold on the PQ to prevent lower priority traffic from being starved by the PQ.

Without LLQ, CBWFQ would not have a priority queue for real-time traffic. The additional classification of other traffic classes is done using the same CBWFQ techniques. LLQ is the standard QoS method for many VoIP networks.

Cisco Press CCDA 640-864 Official Certification Guide Fourth Edition, Chapter 6