Push Content Setup

A cache/proxy plug-in maintains its own cache file structure. This is typical of most cache devices. By using a proprietary system, a cache device or server can handle requests much faster and with less processing overhead. Instead of storing files in a hierarchical system of folders, a cache typically stores all files in one folder, gives each file a unique name, and maintains an index that links a file to a URL. The index is a database that also includes expiration information. Here is how it would work:

1. A user requests a file with a URL such as rtsp://WMServer/File.wmv.

2. The cache/proxy plug-in intercepts the request and looks for the file in its cache file system.

3. If the file is found in the cache and is not expired, the file is streamed. Otherwise, the cache/proxy plug-in requests a new stream from the origin server.

In order to push content to the cache, you cannot simply copy files to a folder. The cache/proxy plug-in or other cache device must initiate the prestuffing process so that the content can be properly entered into the caching system database. The Windows Media Services SDK sample does not support prestuffing. However, a complete cache/proxy plug-in solution that pushes content can be created with the SDK.

To push content, a content management program initiates the Prestuff method from a central location. For example, the prestuffing program can run in Toronto and remotely control the cache/proxy plug-ins at one or more remote sites. The technician can enter the source files to be prestuffed, along with the destinations for the files. Then the program can begin prestuffing the files. A complete third-party content management system or appliance should make the process of prestuffing easy, and should include the ability to cache Web content such as Web pages, image files, and script.

With the installation of the remote servers, Fabrikam has completed the second phase of its Windows Media deployment. Live and on-demand content can be created, and end users throughout the enterprise can stream content. In the last phase, we will see how Fabrikam creates a series of training videos, enables multicast streaming throughout the network, and explores ways to create client usage reports.