Q. What's Microsoft IIS Smooth Streaming?

A. Have you noticed that on some media services, the quality actually changes as you watch based on the detected bandwidth? For example, a media source might switch between high definition and standard definition. Smooth Streaming is a Microsoft technology that's part of IIS Media Services 3.0. It enables this capability for media streamed from IIS to Silverlight and other clients. Using Smooth Streaming, resolutions up to 1080p can be streamed to clients and downscaled to much lower resolutions for clients with lower bandwidths.

The technology works by sending the data in small fragments (around 2 seconds long) and checking that each fragment was delivered in a timely fashion. If delivery wasn't quick enough, a lower quality will be used in the next fragment. Similarly, if it was delivered very quickly, a higher quality will be tried. This variable quality is achieved through encoding the media at different quality levels.

If you watched the 2008 Summer Olympics on NBCOlympics.com, you saw Microsoft Smooth Streaming in action, and you can also see on the IIS site. As you can see, it shows the bandwidth its actually using. In my case, as you can see here, it started at 350kbps and went up to 1.52Mbps based on available bandwidth. (It's not a bad cartoon, not quite Shrek Laughing. It's actually pretty mean as it goes on, but if you want to see a giant rabbit go Rambo on three evil forest animals, you'll love it.)

IIS Smooth Streaming

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