2. BitTorrent is an open-source peer-to-peer protocol designed for the transfer of large files. The central philosophy underlying BitTorrent is that users should upload data simultaneously with their downloading which maximizes network bandwidth efficiency. BitTorrent is designed to be more efficient and will work better if there are more people interested in a specific file. The protocol is the brainchild of programmer Bram Cohen, who designed it in April 2001 and released a first implementation on 2 July 2001. It is now maintained by Cohen's company BitTorrent, Inc. What is BitTorrent..?
3. Peer-to-peer protocols, use a network of clients (each functioning as a server) to send data to other users who are looking for similar files. The only server in a BitTorrent network is a tracker which monitors which files are available and where, and directs clients who are looking for the files for downloading to where the files are available. Peer-to-peer transfer protocols are less expensive than the client-server model. Another advantage of BitTorrent is that it is an open source application. BitTorrent is free unlike other peer-to-peer systems (e.g. Kazaa, Gnutella). Any user can download the software and have it ready for use. In-house programmers can also modify the system to their companies' specific needs and requirements. BitTorrent: Peer-to-Peer File Transfer Protocol
4. The transfer speed is affected by a number of variables, including the type of protocol, the amount of traffic on the server and the number of other computers that are downloading the file. If the file is both large and popular, the demands on the server are great, and the download will be slow. Traditional Client-Server Downloading
5. Peer-to-peer file sharing is different from traditional file downloading. In peer-to-peer sharing, you use a software program (rather than your Web browser) to locate computers that have the file you want. Because these are ordinary computers like yours, as opposed to servers, they are called peers . The process works like this: You run peer-to-peer file-sharing software on your computer and send out a request for the file you want to download. To locate the file, the software queries other computers that are connected to the Internet and running the file-sharing software. When the software finds a computer that has the file you want on its hard drive, the download begins. Others using the file-sharing software can obtain files they want from your computer's hard drive. Peer-to-peer File Sharing
6. The file-transfer load is distributed between the computers exchanging files. Some people download files and immediately disconnect without allowing others to obtain files from their system, which is called leeching . This limits the number of computers the software can search for the requested file. Gnutella's peer-to-peer download process
7. Unlike some other peer-to-peer downloading methods, BitTorrent is a protocol that offloads some of the file tracking work to a central server (called a tracker ). Another difference is that it uses a principal called tit-for-tat . This means that in order to receive files, you have to give them. This solves the problem of leeching -- one of developer Bram Cohen's primary goals. With BitTorrent, the more files you share with others, the faster your downloads are. Finally, to make better use of available Internet bandwidth, BitTorrent downloads different pieces of the file you want simultaneously from multiple computers. What BitTorrent Does
8. You open a Web page and click on a link for the file you want. BitTorrent client software communicates with a tracker to find other computers running BitTorrent that have the complete file ( seed computers) and those with a portion of the file (peers that are usually in the process of downloading the file). The tracker identifies the swarm , which is the connected computers that have all of or a portion of the file and are in the process of sending or receiving it. BitTorrent's peer-to-peer download process
9. The tracker identifies the swarm , which is the connected computers that have all of or a portion of the file and are in the process of sending or receiving it. The tracker helps the client software trade pieces of the file you want with other computers in the swarm. Your computer receives multiple pieces of the file simultaneously. If you continue to run the BitTorrent client software after your download is complete, others can receive .torrent files from your computer; your future download rates improve because you are ranked higher in the "tit-for-tat" system. Downloading pieces of the file at the same time helps solve a common problem with other peer-to-peer download methods: Peers upload at a much slower rate than they download. By downloading multiple pieces at the same time, the overall speed is greatly improved. The more computers involved in the swarm, the faster the file transfer occurs because there are more sources of each piece of the file. For this reason, BitTorrent is especially useful for large, popular files. Here's how it works:
10. It is important to be aware of the terminology used when downloading torrent files: Client - A client is the actual P2P sharing program and it is usually an application that is downloaded and installed on the computer that you would like to use for sharing and downloading files. Two popular P2P clients are Azureus and UTorrent (more on these clients below). Tracker - A tracker is a central server that manages the sharing of files among its many users. Most clients have built in trackers; there are also specific tracking programs such as BNBT and CBTT. Seeder - A seeder is considered a computer that has a complete copy of a file another computer is requesting. For instance, if you would like to download an mp3, you must first make sure that the tracker can find a full copy (seed) of the file that you would like to download. Important Terms You Should Know When Downloading Torrent Files
11. Leeches - A leach is a person that is downloading a file or files from other computers, but is not sharing any files of his or her own. Leeching is considered bad etiquette on P2P clients. Swarm - A swarm is when two or more computers are simultaneously downloading and sharing the same file. Most clients allow a computer to download a file and then upload to others the parts that already have been downloaded. .torrent - a torrent is a file that is downloaded from an index web site and sometimes referred to as an archive. It is a very small file usually less than 25bits, that is necessary for your client to start and manage the file transfer process so you can download the file. Important Terms You Should Know When Downloading Torrent Files
12. First download and install a torrent client. Remember the torrent client is considered the command center for your P2P file sharing. You can choose many different types of torrent sharing clients; however two highly recommended clients are UTorrent and Azureus. Once you have your torrent client downloaded and installed, you will need to search for files that you would like to download. Usually you can visit many index web sites such as Pirate bay and Torrent Spy. Most torrent clients have a list handy of the best index web sites. Now, just search for the file that you would like to download. Some of these sites offer advanced searches such as the ability to search for a video file, music file, application file or all of the above. It is usually extremely easy to locate the torrent file that you would like to download. Once you have searched for a specific file, your index web site should return a list of available torrent files. Look to see which torrent files have the most seeders, usually this will give you the fastest download times and highest quality files. How to Download a Torrent File
13. Once you find the torrent file that you would like to download, click the download link and save it onto your computer. These files are usually very small, around 200kb. Now that you have the torrent file or archive on your computer, double click this file and your torrent client should automatically open up. At this time, the tracker program will come online as well and will start to manage and download your file. While each client and tracker program is different, you should be able to see how many people are downloading the file, seeding and sharing or leeching. You should also see the progress of your computer downloading the file and the amount of time remaining until the file is completely downloaded. All you have to do now is waiting until all the data is downloaded and then you can enjoy your new downloaded file. How to Download a Torrent File
14. While there are more than a dozen P2P torrent clients available, two of the top rated P2P torrent clients are UTorrent and Azureus. Utorrent Utorrent is actually torrent and means micro torrent. It is a freeware Bit Torrent client that works great on Windows computers. The major feature of this Bit Torrent client is that the entire program is only around 200 Kb. This program was developed to require the least amount of computer resources and give as much functionality as possible. Although UTorrent is extremely small it has a lot of features including Unicode support, protocol encryption, peer exchange with other UTorrent users and Azureus users (this feature goes above and beyond normal P2P, similar to chat), configurable bandwidth settings, Customizable user interface, initial seeding and the availability of this application in 38 languages. Top P2P Torrent Clients
15. Azureus is another P2P Torrent Client, it is based on Java (You need to have JRE installed, but that is very common).It is also a free software client and it works on many different platforms including Windows, Mac, Linux and UNIX. One of the key features of Azureus is that it allows multiple download files easily from a GUI interface. You can also open up and view or hear files that are currently downloading, but not yet complete. This makes it easy to check the quality of the file before you spend a significant amount of time downloading it. Azureus has its own tracker program so you can easily share files without uploading them to centralized sites. Azureus is considered one of the top Bit Torrent clients and has a wealth of features that are designed and integrated into the client very well. Top P2P Torrent Clients
16. ABC - Another BT client BitTornado G3 Torrent BitComet Vuze (Azureus 3.0) Some other BitTorrent Clients
22. BNBT is a complete port of the original Python-based BitTorrent tracker for speed and efficiency. BNBT also offers many additional features not present in the original tracker. CBTT is a modified BNBT-Based BitTorrent tracker project developed primarily by DreadWingKnight EasyTracker is a customized version of BNBT specifically designed for Windows users. It even comes with an installer and detailed installation and customization instructions. XBNBT is a modified, open source, BitTorrent tracker based on BNBT, offers many additional features such as support for flat-file or MySQL database operation, control over TCP parameters, additional administrative, statistics, and control options, additional filter and search facilities, and more. BitTorrent Trackers
23. Lack of anonymity BitTorrent does not offer its users anonymity. It is possible to obtain the IP addresses of all current, and possibly previous, participants in a swarm from the tracker. This may expose users with insecure systems to attacks. Dialup versus broadband BitTorrent is best suited to continuously connected broadband environments, since dial-up users find it less efficient due to frequent disconnects and slow download rates. Limitations and security
24. The leech problem BitTorrent file sharers, compared to users of client/server technology, often have little incentive to become seeders after they finish downloading. The result of this is that torrent swarms gradually die out, meaning a lower possibility of obtaining older torrents. The cheater problem There are "cheating" clients like BitThief which claim to be able to download without uploading, and because of this can sometimes download faster than regular clients. Such exploitation negatively affects the cooperative nature of the BitTorrent protocol. Limitations and security
25. Bit Torrent Clients are usually the fastest, most affordable and most convenient way to share files among many users. Most Bit Torrent P2P users can find plenty of files available and download them with ease. With the explosion of broadband, you can easily find and download files of any size, from mp3's to large multi gigabyte video files. But, sometimes Bit Torrent clients include adware or spyware, so it is favorable to use this only if you’re having An effective antivirus application with spyware & adware detector. Make sure you always download the client from the official web site and read the EULA (end user licensing agreement) to make sure there are no adware or spyware included. Conclusion
