Local area networks based on the IEEE 802.11 standard represent the largest deployment of wireless network technology worldwide, and such networks have accelerated the growth of multimedia applications. This type of content requires special settings to ensure quality of service, specially in the case of real-time video streaming. Currently, the state of the art mostly focuses on solving the QoS problem over traditional IEEE 802.11 networks, but few works try to evaluate the performance of QoS mechanisms over software-defined WLAN network scenarios. The Software Defined Networking (SDN) architecture helps to improve, simplify, and program the network management according to specific needs, making the design and deployment of new control policies easier and faster to implement. This paper presents an analysis of throughput and delay metrics behavior of QoS mechanisms from IEEE 802.11 standard such as admission control, implemented over a emulation scenario based on NS-3 integrated with SDN.