Upgrading from the Previous Release
Media Files that are not Throttled
The Bit Rate Throttling module for Windows Server 2008 enables Web administrators to throttle the delivery of any file based on the file type, with additional advanced functionality for digital audio/video files. Throttling can be set at the following levels within Internet Information Services (IIS) Manager: server, site, virtual directory, and file.
For audio and video files, this module automatically detects the encoded bit rate of the file, sends a short burst of data to the client at full throttle to ensure a fast start to their playback experience, and then delivers the content at a throttled rate that is equal to or slightly greater than the encoded bit rate. Several popular digital media file types are pre-defined in the module, and others can be added. Data files are throttled at a configurable constant rate.
The Bit Rate Throttling module includes the following key features:
· Integration with IIS 7.0. The Bit Rate Throttling module is tightly integrated with this new administration interface and configuration store in IIS 7.0. In addition, IIS 7.0 has a new administration tool, and the new Bit Rate Throttling module plugs seamlessly into that paradigm.
· Throttling for any file type. Any file type can be throttled at a constant rate. An administrator can easily specify a new file type and throttling settings through the user interface.
· Advanced media throttling. One of the most significant features in the new Bit Rate Throttling module is the advanced support of audio/video media formats. This includes automatic detection of the encoded bit rate in a file, and intelligent progressive-download throttling based on that. Built-in support is included for digital media with the following file name extensions: .asf, .avi, .flv, .m4v, .mov, .mp3, .mp4, .rm, .rmvb, .wma, .wmv. An administrator can simply enable Bit Rate Throttling and start intelligently delivering these common media types using the default throttling settings.
· Extensibility. The new Bit Rate Throttling module supports developer extensibility, making it possible for software vendors and hobbyists to add support for additional media formats using simple XML editing. Microsoft is using this extensibility feature to implement the built-in media format support.
· Shared hosting support. By fully integrating into the IIS 7.0 pipeline and configuration model, the new Bit Rate Throttling module makes it possible to host Web page content and intelligently deliver a variety of media from the same Web server, site, or virtual directory. This level of granularity also provides the ability to isolate users through per-user virtual directories.
The following prerequisites must be fulfilled to install the Bit Rate Throttling module:
· You must use IIS 7.0 running on Windows Server 2008.
· The IIS Management Console for Internet Information Services 7.0 must be installed to manage the Bit Rate Throttling module using the IIS 7.0 user interface.
· You must install the Bit Rate Throttling module as an administrator. (See Downloading and Installing for more information.)
Two separate downloadable packages are available for the Bit Rate Throttling module. Download the appropriate package for your version of Windows:
· Bit Rate Throttling for IIS 7.0 (x86)
· Bit Rate Throttling for IIS 7.0 (x64)
You must be an administrator on the computer to run the installation package. This can be accomplished by one of the following methods:
· Log on to the computer using the Administrator account.
· Log on to the computer using an account with administrative privileges, open an elevated command prompt (Click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator), and then type the following command to run the installation:
msiexec /I bitrate32.msi
If you encounter any problems during installation, type the following command in the elevated command prompt to create a log file that contains information about the installation process:
msiexec /L bitrate.log /I bitrate32.msi
Analyze this log file after a failed installation to help determine the cause of the failure.
Upgrading from the previous release of the Bit Rate Throttling module is not supported for this release. To get the new features and updates in this release, you must first remove the current Bit Rate Throttling module. For more information, see Uninstalling.
If you elect to remove the Bit Rate Throttling module in IIS Manager, the module is removed from the Web server; however, custom settings for bit rate throttling at different configuration levels are not removed. After the module is removed, IIS may not be able to read the web.config file at these levels and could return an error.
Before removing the module, open it at the site level, and then click Revert to Inherited in the Actions pane to delete local configuration settings. You can then safely proceed with removing the module. For more information, see Remove a Managed Module.
Most pre-defined media format files are throttled correctly. However, some non-standard files may have differences in the file header that cause the Bit Rate Throttling module to not detect the encoded bit rate. When this occurs, the file is downloaded to clients with no throttling applied.
The following walkthroughs for the new Bit Rate Throttling module are available on IIS.net:
· Bit Rate Throttling Setup Walkthrough. Describes how to download and install the Bit Rate Throttling module.
· Bit Rate Throttling Configuration Walkthrough. Describes how to configure the Bit Rate Throttling module at the server, site, virtual directory, and file levels.
· Bit Rate Throttling Extensibility Walkthrough. Describes how to use the extensibility interface provided by the Rate Throttling module to add support for additional media file types.
Also, be sure to visit the IIS Media Delivery Blog where IIS team members who work on digital media will talk about the Bit Rate Throttling module and other technologies in the pipeline that will help you better serve digital media content to your users.
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