350-501 Automation and Quality of Service Practice Question
An engineer is configuring QoS for voice traffic on a Cisco router. Which marking should be applied to voice packets to ensure proper end-to-end prioritization?
⚠ Common exam trap
Cisco often tests the distinction between voice bearer (RTP) and voice signaling (SIP/H.323) markings, so the trap here is that candidates confuse DSCP CS3 (for signaling) with DSCP EF (for actual voice payload), or assume IP Precedence 3 is sufficient despite its lack of strict priority behavior.
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
✓
DSCP EF
Voice traffic requires low latency, jitter, and packet loss. DSCP EF (Expedited Forwarding, per-hop behavior value 46) is the standard marking for real-time voice payloads, ensuring strict priority queuing (PQ) across the network. RFC 3246 defines EF for this purpose, and Cisco routers use it to map voice to the priority queue.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
DSCP AF41
Why it's wrong here
DSCP AF41 is used for multimedia conferencing, not voice.
- ✗
DSCP CS3
Why it's wrong here
DSCP CS3 is for broadcast video, not voice.
- ✓
DSCP EF
Why this is correct
DSCP EF is the correct marking for voice payload.
- ✗
IP Precedence 3
Why it's wrong here
IP Precedence 3 corresponds to DSCP 24, typically used for voice signaling.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.