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How to Make Wireless Voice and Video Work for You


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BY LISA A. PHIFER W


IRELESS LANS (WLANs) are now well on their way to replacing wired Ethernet as the primary enterprise network access method. As


organizations navigate this migration, making significant network infrastructure upgrades, it is important to consider optimizing network performance to meet needs associated with real-time applications like voice over IP and videoconferencing. Most 802.11n access points (APs) can support data rates


up to 300Mbps, with 450Mbps now emerging. These higher data rates increase total WLAN capacity, making it possible to support more users per AP as well as high-throughput applications such as video streaming. But these changes are not necessarily good for real-time applications that require frequent and predictable network access. In this guide, we look at what it takes to support these applications, and how those needs impact wired/wireless network integration.


Application Traffic


and WLAN Optimization Real-time applications are sensitive to latency (the


time it takes for a packet to travel from point A to point B) and jitter (variation in packet arrival time). When media is streamed—such as watching a YouTube video or listening to a podcast—arriving packets can be buffered to compensate for latency and jitter. However, real-time applications like voice calls, videoconferencing, instant messaging, and unified communication cannot depend upon buffers to smooth over those network “speed bumps.” Real-time application users expect immediate communication, without odd drop outs or lags in what they see and hear. Under the covers, this requires the ability to send


packets frequently, at fixed intervals, with consistently fast delivery. Voice over IP always sends short fixed-length packets that carry digitized voice, compressed by a codec


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VOLUME 4 • ISSUE 2


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