Which two statements are true about priority queuing (PQ)? (Choose two.)

Which two statements are true about priority queuing (PQ)? (Choose two.)
A . Traffic in the highest priority queue will experience the least amount of jitter and delay compared to traffic in the other queues.
B . Traffic in the highest priority queue is only reserved for voice traffic.
C . Traffic in lower priority queues can be starved of bandwidth.
D . Traffic in all queues are always guaranteed a minimum bandwidth.

View Answer

Answer: A, C

Explanation:

Priority queuing (PQ) is a queuing method that establishes four interface output queues that serve different priority levels: high, medium, normal, and low. Traffic in the highest priority queue will experience the least amount of jitter and delay compared to traffic in the other queues, because PQ always services the higher-priority queues first. However, this can also cause traffic in lower priority queues to be starved of bandwidth, especially if the highest priority queue is oversubscribed. Traffic in the highest priority queue is not only reserved for voice traffic, but can also include network control and routing traffic. Traffic in all queues are not always guaranteed a minimum bandwidth, because PQ does not provide any bandwidth reservation mechanism.

Reference: Quality of Service (QoS) Queues and Queuing Explained, Chapter: Configuring Priority Queueing – Cisco