SteelHead™ Deployment Guide - Protocols : Video Optimization : Overview of Video Optimization
Overview of Video Optimization
You can use video to disseminate information either through live or recorded content. As of RiOS v7.0 there are two solutions for video optimization:
  • Live Streaming with split-streaming - Live streams are only available at a specific time. Examples include video streams of a live sporting event or broadcasting executive events to the workforce. In RiOS v7.0, you can optimize live streaming video with HTTP stream splitting.
  • For more information about HTTP stream splitting, see HTTP Stream Splitting.
  • On-demand with HTTP prepopulation - On-demand streams are stored on a server and transmitted when requested by a user: for example, training videos. In RiOS v7.0 or later, you can optimize pre-recorded video by using HTTP prepopulation.
  • For more information about on-demand with HTTP prepopulation, see Video On-Demand with HTTP Prepopulation and the HTTP Prepopulation.
    Distribution of video impacts not only the overall bandwidth use, but also impacts other services running on the network. In the case of live broadcasting, you might need multiple simultaneous streams per broadcast to support multiple bit rates (for example, remote or wireless workers might watch video at a lower bit rate, while viewers in the office might watch video at a higher bit rate for a larger screen). As the number of streams increases, the likelihood increases that other services, such as email, are affected.
    Depending on the codec, resolution, and software in use, video distribution can use anywhere between 16 Kbps (for a low resolution, highly compressed video stream optimized for a small display) to 15 Mbps or more (for a high resolution HDTV stream) per stream. Typical enterprise video streams use between 350 and 500 Kbps to support a single user desktop application.
    Connectivity can be overwhelmed quickly and does not scale well when you compare these speeds to typical branch office connectivity, in which you send a single stream for each user. For example, a typical T1circuit running at 1.544 Mbps (or an E1 running at 2.048 Mbps) might be able to serve users’ needs for many business applications, but it cannot support more than 4 or 5 concurrent video streams. When the entire company might be watching a video broadcast or video conference at the same time, the need for efficient delivery of video across the WAN becomes clear.
    When you optimize video streams of either type, you reduce the overall impact of video traffic on the WAN, thereby ensuring service continuity and optimal user experience.