300-430 Question 46
Single answerAn enterprise network requires high-quality voice traffic over wireless. The network administrator must implement QoS to ensure that voice traffic maintains priority from the wired network to the wireless network. Which QoS mechanism should be used to map the wired DSCP value for voice traffic to the appropriate 802.11e wireless QoS category?
- A
Mark the wired DSCP value to 46 and map it to the wireless AC_VI (Video) category.
- B
Mark the wired DSCP value to 46 and map it to the wireless AC_VO (Voice) category.
- C
Mark the wired DSCP value to 34 and map it to the wireless AC_VO (Voice) category.
- D
Mark the wired DSCP value to 26 and map it to the wireless AC_BE (Best Effort) category.
Show answer and explanation
Correct answer: B
Explanation
In QoS configuration, it is critical to maintain consistent traffic prioritization across wired and wireless networks. DSCP 46 is the standard value for voice traffic in wired networks, and it needs to be mapped to the AC_VO (Voice) category in the wireless 802.11e QoS framework. This ensures that voice traffic receives the highest priority, minimizing latency and jitter for real-time communication.
- A. Incorrect.
Mapping DSCP 46 to AC_VI is incorrect because DSCP 46 is specifically reserved for voice traffic, which should be mapped to the AC_VO category for low latency and high priority.
- B. Correct.
Mapping DSCP 46 to AC_VO is correct because DSCP 46 is the standard for voice traffic on wired networks. This ensures that voice traffic maintains priority in the 802.11e wireless environment by mapping it to the AC_VO (Voice) category.
- C. Incorrect.
Mapping DSCP 34 to AC_VO is incorrect because DSCP 34 is typically used for signaling traffic, not voice traffic. Voice traffic uses DSCP 46.
- D. Incorrect.
Mapping DSCP 26 to AC_BE is incorrect because DSCP 26 is used for lower-priority traffic, and mapping it to the Best Effort category does not prioritize voice traffic.