Introduction
Ever wonder how that friend of yours has every episode of Seinfeld, movies that are still in theatres and more music than you can stuff on an iPod? The answer is BitTorrent. BitTorrent is a file sharing protocol which has grown to comprise nearly 50% of all internet traffic (according to some surveys). However, the average computer user most likely does not know how to use this powerful technology. This guide will introduce the basic principles behind the BitTorrent protocol, show you how to download any torrent file in two simple steps and contains information about various torrent sites on the net.
What is Bit Torrent?
Bit Torrent is a file transfer protocol. It is simply a way of sharing and sending data over the internet. This data could literally be anything, from small MP3s to large Xvid movies. The difference between BitTorrent and other file transfer protocols (like simply downloading a file from a website) is that BitTorrent works by simultaneously downloading (receiving) and uploading (sending) the content. In practice, using BitTorrent is much simpler than understanding how it works, so if you don’t really care about the details, skip the next section.
How does Bit Torrent Work?
The best way to understand how BitTorrent works is by breaking the process into steps. Say you want to download a free album. The first thing you’ll need to do is locate a torrent file on a website that hosts the torrent file for the album. Once you have located the torrent file, you must download it from the website.
What is the .torrent file?
The .torrent file is a very small file that acts like a pointer. The file points your torrent client towards the data stream for the particular file(s) you want to download.
What is a BitTorrent client?
A BitTorrent client takes the torrent file and reads it. The torrent file has information about a tracker. The client directs your computer to connect to the tracker, which delegates the sending and receiving of the file amongst various computers. Aside from this, the client acts like many file sharing programs by allowing you to set the download path for your files, as well as set your maximum upload speed. The tracker is a program running on a remote server which directs the flow of data. The tracker has no idea what contents it is directing, but merely tells how users should share their data by determining who is connected to the tracker. For example, if your client connects to the tracker looking for the album you want, the tracker searches the other connected users for people who have the whole file or part of the file, it gives your client this information. Once complete, your torrent client can begin downloading and uploading data.
Then how do I download the file? The BitTorrent client handles this process. Each file, in this case an album, is broken into various parts - so user A could have part 2 of 10 and user B could have part 1, and you can download both files from both users simultaneously, thus speeding up the file transfer. Individuals who are sharing and have the whole file, or all parts of the torrent are called seeds, other users are called leeches because they are still leeching, or downloading from other individuals. Obviously, a torrent with a higher ratio of seeds to leeches will download much faster. In any case, once the various parts have all been downloaded, they are reassembled into the original file by the client and stored on your hard drive at the location you saved them.
Why is this better?
The BitTorrent protocol has several key benefits. Essentially, it is a more democratic form of filesharing. The BitTorrent network utilizes all individuals engaged in the file transfer process to maximize efficiency. Because everyone is simultaneously sending and receiving data, the bandwidth needed to send the file to all of the users is shared amongst all of the users, reducing the expense of publishing such files on the internet for direct download from a server to each of the clients. Instead, the server that wishes to publish the files needs to only have a tracker operate and an initial uploader or seeder to begin sharing the file to others. The BitTorrent network efficiency increases as the number of users increase for this reason, so files with large demand (such as a newly released movie or album) are downloaded much faster by everyone because of the higher number of individuals sharing them.
OK, how do I get started downloading?
Downloading files using the BitTorrent protocol is quite simple. First, you’ll need to download and install a BitTorrent client. A list can be found at Wikipedia. Once you have installed the client, you can start downloading files, you just need to find them. uTorrent and Azureus are arguably the most popular clients.
There are literally thousands of places to download .torrent files on the web. Google is your friend, or you can sign-up to ThePeerGroup - a BitTorrent community hub.
Written by Coolstuff, edited by MonkeyNut.