DNA Client – Distribution

It is strongly recommended that content providers distribute BitTorrent DNA to end users.  This can be accomplished in one of four ways:

1. (For Downloads) By using a DNA Downloader for each web object to be accelerated.  A DNA Downloader first installs the BitTorrent DNA client and then immediately triggers a peer-accelerated download of the web object.  See DNA Downloader for details on how to create a DNA Downloader.
2. (For Streaming) By using a DNA Video Player for displaying each video to be delivered.  The DNA Video Player can either suggest or require installation of the BitTorrent DNA client prior to playing a video.  See DNA Video Player for details on how to create and configure a DNA Video Player.
3. By providing instructions on installing the DNA client directly to your end-users.  This can be done in two ways:
   1. Providing users with a link to the BitTorrent DNA client download page: http://www.bittorrent.com/dna/getdna/

      OR

   2. Distribute the DNA client yourself by providing users with a link to the client installer served from your own web infrastructure.  The standard DNA client installer, DNA-Setup.exe, can be found within the DNA client zip bundle on the Tools & Resources Download page.

In general, it is recommend that the call-to-action you present to your end users is about “getting the content” rather than “getting DNA” – getting DNA (and agreeing to the EULA) should be part of the workflow of getting to the content. The reason for this is that DNA is explicitly designed to NOT be a traditional BitTorrent client – we have gone to great lengths to make sure that the end user and content publisher will get the benefits of BitTorrent delivery while eliminating both complexity and other potential negative impacts on the end user experience.

4. By bundling BitTorrent DNA client with an application (e.g. a download manager, game or video player) that is distributed to end users.  A silent version of the DNA client installer, btdna.exe, can be found within the DNA client zip bundle on the Tools & Resources Download page. This silent version of the installer does not require the user to agree to a BitTorrent DNA EULA, or present an installer dialog which a user would agree to as part of the application installer.

   To install BitTorrent DNA, simply un-archive btdna.exe into a temp folder and launch it.  It will install itself to C:\Program Files\BitTorrent_DNA\  and create a Windows registry subkey to store the port number at which it listens for download requests.

   DNA handles all installation logic, including not downgrading, setting registry keys and copying the executable into program files.

   On installation, BitTorrent DNA sets its cache size equal to 20% of the free space on the user’s hard drive, up to a maximum of  20GB. DNA’s use of the end user’s hard drive will never exceed this limit.  The cache size allocation is updated continuously and actively managed, including the deletion of DNA content in case an end users starts to fill their disk with other content.

   If you need to synchronize using DNA (e.g. discover when the application has completed installation), they you may read the registry key:
   
   HKEY_CURRENT_USER/Software/BitTorrent/engine/portTimestamp
   
   Read this key before you launch btdna.exe, and then periodically query it to see when it updates. When it updates it means DNA has completed installing itself (or has completed to decide that it shouldn't install itself to avoid downgrading), and it is ready to be used. This loop should have a timeout of no more than 5 seconds.

   The most reliable way to determining the version of DNA that is installed is to query the registry key: HKEY_CURRENT_USER/Software/BitTorrent/engine/Revision  This will return the build number of the DNA client that is installed.

In each case, end users of BitTorrent DNA MUST agree to the terms of the BitTorrent DNA End User License Agreement (EULA), which may be presented as a separate click-though EULA or as terms that are integrated into an existing EULA.  Distribution of BitTorrent DNA without requiring end users to consent to the DNA EULA is a violation of our Terms of Service. The latest version of the DNA EULA can be found here: http://www.bittorrent.com/dna/dna-eula/