Video Services Module

Video is one of the most demanding traffic types that a network can carry. It combines the high bandwidth requirements of data with the low latency and jitter required for voice. But video is much more sensitive to dropped packets than voice, meaning that it must be delivered reliably.

Meru's Virtual Port technology is ideal for video because it gives every client a dedicated unicast link, using the 802.11 protocols' built-in reliability mechanisms to ensure that each frame gets through. Other wireless systems use 802.11 multicast, which lacks built-in reliability and results in a high packet loss rate. The difference is particularly noticeable in 802.11n networks, where packet loss rates of 10% or more are the norm – a figure that can play havoc with video streams.

For networks carrying large amounts of video traffic, Meru offers a dedicated Video Services Module that runs under the System Director operating system. This adds additional features that help the network scale to large numbers of concurrent video sessions without degrading the user experience:

  • Multicast group management. Like a network switch, a Meru network sends video traffic only to clients that are members of a multicast group. Each multicast data flow is converted to multiple unicast flows, each one customized to the data rate and link characteristics of a single client device. Other vendor's systems work like a hub, wasting bandwidth on both the wired and wireless network by broadcasting video to everyone.
  • Application-aware prioritization. The network automatically synchronizes the picture and soundtrack components of each video stream by using its understanding of video technologies including MPEG-4 and H.264 to ensure that each arrives in order.
  • Video-optimized handoff. The network proactively reconfigures the multicast delivery tree as clients move through a network, preventing lost video frames or interruptions in a voice stream. Like other applications on a Meru wireless LAN, video experiences no handoff latency because each client remains connected to the same Virtual Port no matter where in the network it is physically located.
  • Graphic visualization. Network administrators can easily see which clients are running different types of applications (data, voice, video) to aid in monitoring network-wide application performance.