1. Presented by Stephen Kozy

2. Presentation Outline Definition and explanation Comparison and Examples Advantages and Disadvantages Illegal and Legal uses

3. What is BitTorrent? BitTorrent is a peer-to-peer (P2P) file sharing protocol. BitTorrent allows the transfer of large files without having to worry about: Hardware Bandwidth Hosting

4. History of BitTorrent Created by programmer Bram Cohen Released on July 2, 2002 Now updated and operated by BitTorrent, Inc.

5. Some definitions related to BitTorrent: Torrent: a file that contains metadata and tracking information for a file to be downloaded. Tracker: a server that assists clients in locating other clients and negotiating the trading of parts of a file. Part: a small chunk of a larger file. Client: a program used to open a torrent file. Seeder: a connected client that contains 100% of the file to be downloaed.

6. How does it work? Uses a file called a “Torrent” (*.torrent) that includes metadata and tracking information for the file to be downloaded. User uses a BitTorrent client to open the torrent file, which begins the file download. The tracker assists peers using the torrent in locating each other. Users connected to the torrent upload and download parts of the file.

7. How does it work? (continued) Every user connected to the torrent is capable of requesting or transmitting any part of the file. “Seeders” remain connected to the torrent even when they have a compete copy of the file.

8. How does it work? (example A) 12345678910111213 12345678 1234 Source Client A Client B Original download method

9. How does it work? (example B) 12345678910111213 12378101113 156891213 Seed Client A Client B BitTorrent download method

10. How does it work? (example C) Source: http://en.wikipedia.org/wiki/Bittorrent

11. Advantages Allows higher download rates. Negates any server down time. Equalizes the burden of hardware requirements, hosting, and bandwidth across all users of the file.

12. Disadvantages Downloads can be slow to start due to the limited number of connections found when starting a torrent download. Downloads can be difficult to finish if many users do not have a particular part of the file. Recent updates to Windows limit the number of internet connections any one computer may have at one time. BitTorrent is often used for illegal purposes and has become notorious for that use.

13. Popular BitTorrent Clients BitTorrent Azureus – fully featured BitTornado – light and easy BitComet uTorrent

14. Common Illegal Uses Transfer of movies and music Transfer of licensed software Transfer of video games

15. Common Legal Uses Linux distributions Small software companies World of Warcraft automatic updater

16. Conclusion BitTorrent is a relatively new protocol in the file sharing world. P2P software has gotten a bad reputation from its many illegal uses. BitTorrent is one of the few P2P protocols being widely used for legal purposes, and will continue to grow in use in the years ahead.