Fast Streaming

Applies To: Windows Server 2008, Windows Server 2008 R2

Fast Streaming provides the following group of features in Windows Media Services that combine the advantages of streaming and downloading to improve the quality of streaming media content for the user:

The server can use the Fast Start and Advanced Fast Start features to ensure that the client can begin playing the content as quickly as possible after the stream begins. The Fast Start feature enables the player to download and buffer a small portion of the content from the server as fast as the network will permit before the content begins to play. After the buffer has been filled on the player, the server slows down the stream until it matches the rendering speed of the player.

The server can take Fast Streaming one step further by using the Advanced Fast Start feature to enable clients to begin playing the content even before the player's buffer is full. When the player receives a minimum amount of data, it can begin playing the content. The player's buffer continues to fill at an accelerated rate—a rate that is faster than the encoded bit rate of the content. When the buffer is full, Fast Start acceleration stops and the player begins receiving data at the encoded bit rate.

When the server uses the Fast Cache feature, it streams all of the content to the player at the highest possible bit rate so that the effects of network congestion or interruption can be minimized. As with normal streaming, the player begins rendering the content when the necessary amount of data has been buffered. The rest of the data is stored in a temporary cache on the client computer.

If you are streaming variable-bit-rate (VBR) content, the amount of bandwidth required to transmit the stream can fluctuate based on the complexity of the content. Fast Streaming can take advantage of periods of lower bandwidth by sending extra data to the player to replenish the content buffer, enabling the VBR content to play back smoothly when streamed from the server.