300-430 Question 48
Single answerAn organization is implementing QoS for their enterprise wireless network to ensure voice traffic is prioritized over other types of traffic. When configuring QoS on the wireless LAN controller (WLC), they need to ensure proper mapping of wired QoS markings to wireless QoS categories. Which QoS scheme correctly maps wired DSCP values to wireless priority levels?
- A
DSCP values are mapped to IEEE 802.11e Access Categories (AC) based on four QoS categories: Voice, Video, Best Effort, and Background.
- B
Wired DSCP values are ignored, and all traffic is treated equally on the wireless network.
- C
DSCP values on the wired side are directly mapped to the wireless QoS profile without any modification.
- D
The WLC maps DSCP values to 802.1p values, which are then mapped to wireless Access Categories.
Show answer and explanation
Correct answer: A
Explanation
In a proper QoS implementation, wired DSCP values must be translated into wireless QoS categories to ensure end-to-end traffic prioritization. IEEE 802.11e defines the Access Categories (AC) used in wireless networks, which include Voice, Video, Best Effort, and Background. This mapping ensures that high-priority traffic like voice and video is treated appropriately in a mixed wired-wireless environment.
- A. Correct.
Correct. DSCP values are mapped to IEEE 802.11e Access Categories (AC) to ensure proper prioritization of traffic types such as Voice, Video, Best Effort, and Background. This mapping is essential for maintaining QoS from wired to wireless networks.
- B. Incorrect.
Incorrect. Wired DSCP values are not ignored in a properly configured wireless QoS implementation. Ignoring DSCP values would result in loss of traffic prioritization.
- C. Incorrect.
Incorrect. DSCP values are not directly mapped without modification; they are translated into wireless QoS categories based on the IEEE 802.11e standard.
- D. Incorrect.
Incorrect. The mapping process involves translating DSCP values to Access Categories, not 802.1p values. 802.1p is used in wired networks but does not directly apply to wireless QoS implementation.