BitTorrent HOWTO

=About Bittorrent= Bittorrent is a way to quickly and efficiently distribute large amounts of information.

You need a bittorrent application to download the data available here. We provide a list below. By using Bittorrent, you are making it possible for other people obtain these files. The Bittorrent protocol is the only way to distribute large amounts of data to a unlimited number of people without funding. The data available via bittorrent (.torrent files) on 911datasets.org is hosted by you the users, not this site.

Our goal is to build a group of supporting researchers who insure the availability of this data forever. Bittorrent is a well established protocol. It accounts for more than 1/2 of all internet traffic.

The .torrent files hosted here are created on the original folder structures, therefore it is not necessary to unpack or decompress the dataset after completing the download. If the originally released files were compressed into groups (for example in a .zip) then the .torrent file is created on the uncompressed result. This makes it possible for you to use the data downloaded while helping other users download it by continuing to seed the torrent.

Please consider allowing your bittorrent client software to provide this information to others ("seeds" in bittorrent lingo) after your download is complete.

'''You can directly support this site in the most important way by leaving your bittorrent client running after the download is complete. This is the only way the files posted here are available, by users seeding the torrents after downloading.''' All modern BitTorrent clients can be configured to automatically start when ones computer reboots, and if necessary one can limit the bandwidth used.

Transmission

 * Transmission (Linux, Mac, BSD)

uTorrent

 * µTorrent (Windows, Mac) Not open source but free to use. Quick, light weight and easy to use with good support in their forums.

Azureus

 * Vuze (Windows, Mac, Linux)
 * Instructions

Libtorrent

 * LibTorrent (Linux, BSD)

KTorrent

 * KTorrent (Windows, Linux, Mac, FreeBSD)

= Structure of the Torrents = Upon browsing the torrent you'll find that the directory/file structure will look like: 911datasets.org/[datasetname]/[actualdata] or 911datasets.org/[Name of Release Group]/[Release Number]/[actualdata] For example a from Release 31 has the complete path: /911datasets.org/International_Center_for_911_Studies_NIST_FOIA/Release_31/Release 31/42A0355 - G31D1/1686_large.jpg Where everything after Release_31 is the exact structure received from (in this case) NIST.

Links to more information about Bittorrent

 * A Beginners Guide to Bittorrent
 * BitTorrent basics
 * The protocol explained (for the geekier crowd)
 * For those of you who are visual learners: a great graphic visualization for how BitTorrent works.

= Issues =

The torrent is ginormous and I lack the space on my hard drive to host it!

 * This is a common misconception, said in another way: If the torrent is X GB then you need X GB free on your hard drive to download it.


 * This is only partly true. Many of the torrents here are tens or hundreds of GB. If you want to download all X GB then you do need X GB free space on your hard drive, but if you just want a single smaller file that is contained in the torrent you can instruct your bittorrent client to only download that individual file. For example, if there's a 900GB torrent, and inside it is 5MB file that you want, you only need to download the 5MB file. How to do this varies between bittorrent clients. Inside your bittorrent client, there will be a spot that allows you to browse the file structure of the torrent and see the name and size of each file. You can pick a file to focus on and the bittorrent client will attempt to download that file first.

Slow Download
Normally, bittorrent is very fast (assuming more than one or two people are seeding the torrent). If you find that it takes a long time for your .torrent to start downloading, or if it's slow but you are on a broadband connection, you most likely need to "open your bittorrent ports". How to do this depends on the specifics of your computer and network, but in general, if you for example use a wireless router, you need to configure your router to forward the tcp ports used by your bittorrent client to your computer's local IP address from your router.

Instructions on how to forward ports on many popular routers.

DHT and PEX

To find peers in a swarm when trackers are down just enable DHT and PEX in your Bittorrent client.

DHT and PEX explained

I want to pick and choose specific files within a torrent instead of downloading the whole thing

 * For BitTorrent or uTorrent, you can select which files to download when you initially open the .torrent file.


 * If you wish to change which files to download after that, you can select items from the "Files" tab and right-click to change priority (options are: high, normal, low, or don't download)


 * Other BitTorrent clients should also have similar functionality.

Windows error when trying to open files

 * Some file names in this release are rather long, and Windows may have an error when trying to open them; this problem can be minimized/eliminated by making sure your Bittorrent Client is using a folder near the root folder of your computer to download the data to. For example, you may need to make the folder c:\bittorrent_downloads and configure your bittorrent client to use that path for saving torrents.

My internet connection is slow since I started to seed the torrent

 * If you are using a relatively recent bittorrent client, this should not be a issue, but if it is, it's easy to fix. What is happening most likely is that you are using all of your allowed "upstream" bandwidth... and thus there is none left to make the upstream requests required surf the web (making DNS queries ect). To resolve this, open your bittorrent client which is currently seeding (thank you) and note how much upload bandwidth it is using... most likely a number between 100k/s and 2MB/s.... then configure your bittorrent client to limit the upload rate to 75% of that number. Since your maximum download rate is much higher than your upload rate, other web operations should remain unhindered.