CCNP Architecture Practice Question
A network designer is planning a QoS policy for a campus network that carries voice, video, and critical business applications. The design must ensure that voice traffic receives priority treatment with minimal latency and jitter, while preventing starvation of other traffic. Which queuing mechanism should be used on the egress interfaces to meet these requirements?
⚠ Common exam trap
The trap here is selecting CBWFQ because it provides bandwidth guarantees, but it lacks the strict priority scheduling that voice traffic requires to minimize latency and jitter.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Low Latency Queuing (LLQ)
Low Latency Queuing (LLQ) combines a strict priority queue with class-based weighted fair queuing for other traffic. The priority queue is typically used for voice, ensuring minimal delay and jitter, while a policer limits its bandwidth to prevent starvation of other classes. This makes LLQ the correct choice for meeting strict voice QoS requirements.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Class-Based Weighted Fair Queuing (CBWFQ)
Why it's wrong here
CBWFQ provides guaranteed bandwidth per class but does not offer strict priority treatment. Voice traffic would compete with other classes and could experience increased latency and jitter. While it prevents starvation, it does not meet the strict priority requirement for voice, making it unsuitable for this scenario.
- ✗
Weighted Random Early Detection (WRED)
Why it's wrong here
WRED is a congestion avoidance mechanism that drops packets probabilistically based on queue depth. It does not provide strict priority scheduling or guaranteed bandwidth. While useful for TCP traffic, it cannot ensure voice traffic gets priority treatment, so it does not meet the design requirements for low latency and jitter.
- ✗
First-In, First-Out (FIFO) queuing
Why it's wrong here
FIFO queuing treats all packets equally with no prioritization. Voice packets would be delayed behind bursty data traffic, causing unacceptable latency and jitter. It also provides no mechanism to prevent starvation because there is no class differentiation. FIFO is not appropriate for a QoS design that requires strict priority for voice.
- ✓
Low Latency Queuing (LLQ)
Why this is correct
LLQ provides a strict priority queue for voice traffic while also supporting other queues with guaranteed bandwidth. This ensures voice gets minimal latency and jitter, and the policer on the priority queue prevents starvation of other traffic. It is the recommended mechanism for meeting strict voice requirements in a campus QoS design.
About these practice questions
Courseiva writes every 350-401 question from scratch — 1,923 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Cisco exam blueprint
This 350-401 practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 350-401 exam.