Data source plug-ins enable you to stream content from a variety of content sources. Windows Media Services contains the following data source plug-ins:
Any data source accessed must have the appropriate permissions settings for Windows Media Services to retrieve the content from the location. By default, Windows Media Services uses the Network Service account when responding to network authentication and authorization requests. The Network Service account should be granted Read permissions for any data source you want to use with Windows Media Services. For more information, see About rights.
You can create custom data source plug-ins to handle more specific scenarios by using the Windows Media Services SDK. Custom plug-ins should be located in a protected directory to prevent tampering. The protected directory can be any directory that has been set to deny write permissions to unauthorized users.