VoIP QoS Performance Analysis in 802.11ac Networks

Wireless Local Area Networks (WLAN) have become a preferred means of communication by most organizations in recent times. This is partly due to the changing dynamics of employees as the need for ubiquity and mobility continues to rise. In their attempt to reduce cost of doing business, organizations are gradually shifting to the use of their underlying Local Area Networks (LANs) for telephony services using Voice over Internet Protocol (VoIP). In this paper, we study the Quality of Service (QoS) of VoIP in 802.11ac networks under varying networking conditions. We measured various QoS metrics Throughput, Jitter, Latency, Loss Ratio and Mean Observed Score (MOS) using an Extended Service Set (ESS) testbed with IPv4 and IPv6 as network layer protocols. Our result shows a degradation in VoIP quality when background traffic increases. IPv6 VoIP calls had a better Quality compared to IPv4 calls. Security enhancements negatively affected call quality regardless of network layer protocol used. Performance improvements for IPv6 relative to IPv4 calls range between 3% and 30% depending on the QoS metric.