Bit Rate Throttling
Updated: June 10, 2010
Applies To: Windows 7, Windows Server 2008, Windows Server 2008 R2, Windows Vista
A Web server uses progressive downloading to deliver media content to clients. During progressive download, a file is downloaded to a client's Internet cache using all available bandwidth and starts playing as soon as a minimum amount of data fills the client's buffer. A typical broadband connection allows a large part of the file to be downloaded to the client, even if it stops playing it after the first few seconds—a significant waste of bandwidth.
You can save bandwidth and reduce operating costs by using the Bit Rate Throttling extension for IIS 7 to throttle the delivery of any file. The file type determines how the bandwidth and throttling are handled. For media files (audio and video), Bit Rate Throttling automatically detects the encoded bit rate of the file, sends a short burst of data to the client at a maximum rate to ensure a fast start to the client's playback experience, and then delivers the rest of the content at a throttled rate that is equal to or slightly greater than the encoded bit rate. Bit Rate Throttling supports several popular digital media file types, and others can be added. Bit Rate Throttling can also be used to throttle media and data files at a configurable constant rate.
Internet content providers using Bit Rate Throttling on their Web servers can increase revenue by preserving bandwidth to service additional client requests for content. In addition, they can reduce bandwidth costs for media files that might not be played to the end.