Add or Edit Throttle Setting Dialog Box

Applies To: Windows 7, Windows Server 2008, Windows Server 2008 R2, Windows Vista

Use the Add Throttle Setting and Edit Throttle Setting dialog boxes to either create throttle settings for a new file type or edit throttle settings for an existing file type.

UI Element List

Element Name Description

File name extension or MIME type

Type either the file name extension or the Multipurpose Internet Mail Extensions (MIME) type for the file type that you want to throttle. For example, to create throttle settings for WMV files, type either .wmv or video/x-ms-wmv.

By default, Bit Rate Throttling includes MIME types for many popular digital media file types. If you have to throttle additional file types on your Web server, use the Add MIME Type dialog box in IIS Manager to create the MIME types before typing the file name extension or MIME type. For more information, see Configuring MIME Types in IIS 7.

Fast Start

Type the amount of preroll content that is sent to the client buffer before throttling starts. For media files, specify the amount of preroll content to send to the client by typing the duration (in seconds of elapsed time). For data files (or for media files sent as data files), specify the amount of preroll content to send to the client by typing the size in kilobytes (KB).

Throttle rate

Type the rate at which files are delivered to clients after Fast Start finishes. For media files, type a value that is a percentage of the encoded bit rate of the file. For best client performance, this value should be equal to or slightly greater than 100 percent. For data files, type a value in kilobits per second (Kbps).


Bit Rate Throttling may not be able to detect the encoded bit rate of some media files if the encoded file header is not formatted correctly, or it is missing or corrupted. These files will be downloaded to clients and no throttling will be applied. You can specify a default throttle rate for these files in the Advanced Settings dialog box.

See Also


Advanced Settings Dialog Box