The answer is Priority Queuing, specifically implemented as Low Latency Queuing (LLQ). LLQ is the correct choice because it combines a strict priority queue with Class-Based Weighted Fair Queuing (CBWFQ), ensuring that delay-sensitive voice traffic is always serviced first, which directly minimizes latency and jitter for real-time applications like VoIP. In a service provider network, this mechanism prevents voice packets from being queued behind less time-sensitive data, while the priority queue is policed to avoid starving other traffic classes. On the Cisco SPCOR 350-501 exam, this question tests your understanding of QoS queuing mechanisms for voice traffic, often appearing in a scenario where you must differentiate LLQ from alternatives like WFQ or WRED, which do not guarantee strict priority. A common trap is selecting CBWFQ alone, which lacks a dedicated priority queue for voice. Memory tip: think “LLQ = Love Low Queuing” for voice—it always jumps the line.
350-501 Networking Practice Question
This 350-501 practice question tests your understanding of networking. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Which TWO queuing mechanisms best meet the requirements for voice traffic (low latency and jitter) in a service provider network?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "best"
Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
LLQ (Low Latency Queuing)
LLQ is correct because it combines a strict priority queue with CBWFQ, ensuring voice traffic (which is delay-sensitive) is always serviced first, thereby minimizing latency and jitter. The priority queue is policed to prevent starvation of other traffic, making it ideal for real-time applications like VoIP in service provider networks.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
LLQ (Low Latency Queuing)
Why this is correct
LLQ provides a strict priority queue for real-time traffic.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
WRED (Weighted Random Early Detection)
Why it's wrong here
WRED is a congestion avoidance mechanism, not a queuing mechanism for low latency.
✓
Priority queuing
Why this is correct
Priority queuing provides strict priority, ensuring low latency and jitter.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
CBWFQ without LLQ
Why it's wrong here
CBWFQ provides bandwidth guarantees but no strict priority for jitter-sensitive traffic.
✗
FIFO (First In First Out)
Why it's wrong here
FIFO does not prioritize traffic and can cause jitter.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests the misconception that WRED or CBWFQ alone can handle voice traffic, but the trap here is that only LLQ (or strict priority queuing) provides the necessary low latency and jitter by guaranteeing immediate service for voice packets, while other mechanisms introduce delay or drop packets.
Detailed technical explanation
How to think about this question
LLQ uses a strict priority queue that is serviced before any other class, but it includes a policer (typically configured with the 'priority' command and a bandwidth value in kbps) to limit the amount of traffic that can use the priority queue, preventing queue starvation for other classes. In a service provider MPLS VPN environment, LLQ is often applied on the PE router egress interface to ensure voice traffic from multiple customers meets SLA requirements, with the priority queue policed to the CIR of the voice class.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the 350-501 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Networking — This question tests Networking — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: LLQ (Low Latency Queuing) — LLQ is correct because it combines a strict priority queue with CBWFQ, ensuring voice traffic (which is delay-sensitive) is always serviced first, thereby minimizing latency and jitter. The priority queue is policed to prevent starvation of other traffic, making it ideal for real-time applications like VoIP in service provider networks.
What should I do if I get this 350-501 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "best". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This 350-501 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 350-501 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.