Smooth Streaming is the Microsoft implementation of adaptive streaming technology, which is a form of Web-based media content delivery that uses standard HTTP. Instead of delivering media as full-file downloads, or as persistent (and thus stateful) streams, the content is delivered to clients as a series of MPEG-4 (MP4) fragments that can be cached at edge servers.
Smooth Streaming-compatible clients use special heuristics to dynamically monitor current network and local PC conditions and seamlessly switch the video quality of the Smooth Streaming presentation that they receive. As a result, users experience the highest-quality playback available, with no interruptions in the stream.
As a content producer, you can encode on-demand Smooth Streaming video using Microsoft Expression Encoder 3 (encoding of live Smooth Streams is currently not supported). As a content provider, you can use IIS Media Services to serve the encoded Smooth Streams. And as a content consumer, you can play the Smooth Streams using a Smooth Streaming-compatible client, such as Microsoft Silverlight. This document discusses the Microsoft implementation for delivering a full Smooth Streaming experience.
Get it @ http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=b3752c16-b213-4a30-a54d-1a0491d45ea7.