What is the Akamai Download Manager (DLM)?

The Akamai Download Manager (DLM) provides for more effective, efficient file downloads than is normally available in browsers, especially for large files. It can pause and restart downloads even if you turn your computer off and on again.

Why is VMware using the Akamai DLM?

The Download Manager provides better download capabilities to end users, especially those that have slower internet connections and are having trouble downloading larger files.

The download manager is especially beneficial for:

  • Pausing the downloading of large files
  • Resuming broken or paused downloads (especially for very large files)
  • Downloading files on poor connections

How Does It Work?

The Download Manager is two parallel applications:

  • For Windows Internet Explorer, it is an ActiveX control.
  • For other platforms, it is a Java Applet.

When an end user clicks a link set to use the Download Manager, the following events occur:

  1. DLM checks the User-Agent HTTP header on the user’s request to determine whether the browser supports the Download Manager. If it isn’t supported, the browser is redirected to a URL it can download directly, which happens automatically. The browser will just begin the download as it would with a regular HTTP Download.
  2. For supported browsers, the DLM returns JavaScript that starts the Download Manager ActiveX control or Java Applet.
  3. With most browser security settings, a window will open prompting the user to accept the certificate or signed applet.
  4. If the user rejects the certificate, the ActiveX version automatically redirects to the browser’s download function. The Java version presents a link the user can select if the Download Manager fails to start.
  5. The Download Manager starts, prompting the user with a Save As dialog.
  6. The Download Manager pre-allocates a temporary download file in the user-selected directory. The temporary name is the target file name with .dlm appended. If the user exits the Download Manager—if the download is halted in progress-an icon is created on the user’s desktop that provides for later resumption.
  7. When the file is fully downloaded the temporary file is renamed and the MD5 checksum is verified. We (may) also provide a SHA1 checksum for you on the download page, but the download manager will only perform an MD5 check.
  8. When the download completes the Download Manager may automatically launch the file, if the user selected that option.

System Requirements

The Download Manager runs on a variety of platforms:

  • Internet Explorer 5.01, 5.5, 6.0, and 7.0 on Windows 2000, 2003, XP and Vista. On these platforms it is implemented as an ActiveX control. Internet Explorer is not supported on the Macintosh.
  • The Download Manager runs as a Java Applet, requiring the Sun Java Runtime Environment (JRE) 1.4.x or greater, on Netscape 6, 7, and 8, Mozilla 1.4–1.8, Mozilla Firefox 1.0 or greater, or Safari on Macintosh OS X. For the Macintosh, note that versions of Firefox prior to 1.5 require a third-party plug-in to run JRE 1.4.x or greater; Firefox 1.5 does not need a JRE plug-in installed, and it is supported out-of-the-box.

Users on platforms not using the Download Manager can still download the files, of course, using your browser’s download functionality but without the Download Manager’s features.

Accepting the Security Certificate

Depending on the browser and platform you use, you may be asked to accept a security certificate the first time you use the Download Manager. If you choose not to accept the certificate, and if the web site has provided for alternative links to download files, you can still download the files—just not using the Download Manager.

Download Manager Windows

List Window : When you use the Download Manager, you’ll see one of two windows when the download begins. You may see the List window:

VMware Download Manager


Downloading Multiple Files : This window lists all the current downloads. You can download multiple files at the same time, and you can select files in the list on which to take further actions.

Pause, Resume : You can select from the list of downloads to pause, resume from pause, or cancel the download. If you click Pause, the button changes to Resume.

Pause, Exit, Resume : If you exit, the download manager will place an icon on your desktop that allows you to resume the download later. You can resume the download at any point later, even after you turn the computer off and on. If the file changed at the download site, you’ll be informed of that by a message when you resume download. When you resume, your default browser—the application associated with HTML files—is used. You can override use of the default browser, if desired, by using the “Open with” operating system functionality (for example, in Windows, right-click the file and select Open With). If you started the download with Browser B, you’ll want to pick it up and complete it with Browser B.

Remove, Delete : If you select a completed download in the list, you’ll see a Remove button. This button removes the file from the list. If you click it, you’ll also be asked if you want to Delete the file from your target disk.

Summary Window : If you click the Detail button, you’ll see the Summary window.

Summary Window

Launch, or Close Window : When Done You can pause and resume downloading using the Summary window. If you check the Launch When Done box, the Download Manager will attempt, once the download is completed, to launch or open the file with its associated application. Check the Close box to close this window once the download completes.

How long will it take to complete my download?

Download times will vary based upon the size of the file you are downloading, the speed of your Internet connection, and network conditions.