BitTorrent is a peer-to-peer file sharing protocol invented by Bram Cohen in 2001 that allows users to distribute large files over the Internet. It works by breaking files into pieces that can be downloaded from multiple peers simultaneously, maximizing download speeds. Peers in a BitTorrent network share pieces of files they already have with other peers downloading the same files. This decentralized distribution method avoids overloading any single computer or server with distribution and scales well as more peers join the network.

1. Bit Torrent Presented By: Utsav Dholakia 09BCE009 Guide: Prof. Tejal Upadhyay

2. CONTENTS What Is Bit Torrent ? Origin! Why Bit Torrent ? Torrent Terminology Facts

3. Introduction Bittorrent is a Peer-to-Peer file sharing protocol. One of the most common protocols for transferring large files and accounts . BitTorrent maximizes transfer speeds by breaking down a large file into numerous small pieces and allows the recipient to download each tiny piece from different clients. The only objective of BitTorrent is to quickly give a copy of a single large file to a set of clients.

4. Origin BitTorrent is creation of an American programmer Brahm Cohen. Cohen unveiled his idea at the first CodeCon conference. Cohen wrote the first BitTorrent client implementation in Python, and several other programs have since Implemented the protocol. Bittorrent is designed in April 2001 by Brahm Cohen and then maintained by Cohen ’s company BitTorrent, Inc.

5. Why Bit Torrent ??

6. Traditional Client-server downloading Millions want to download the same popular huge files (for free) Softwares Media (the real example!) You open a Web page and click a link to download a file to your computer. The Web browser software on your computer (the client) tells the server (a central computer that holds the Web pageand the file you want to download) to transfer a copy of the file to your computer. The transfer is handled by a protocol (a set of rules), such as FTP (File Transfer Protocol) or HTTP (Hypertext Transfer Protocol).

7. Router “ Interested” End-host Source Overloaded!

8. Disadvantages Of Client-Server Method Client-server model fails if Single server fails or Can’t afford to deploy enough servers

9. The BitTorrent (P2P)Protocol BitTorrent is a peer-to-peer file sharing protocol allowing users to distribute large amounts of data without putting the level of strain on their computers that would be needed for standard Internet hosting. 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.

10. P2P PROTOCOLS

11. Advantages of P2P Method No central point of failure E.g., the Internet and the Web do not have a central point of failure. Most internet and web services use the client-server model (e.g. HTTP), so a specific service does have a central point of failure. Scalability Since every peer is alike, it is possible to add more peers to the system and scale to larger networks.

12. Disadvantages of P2P Computing Disadvantage of P2P Computing Decentralized coordination. All nodes are not created equal.

13. TERMINOLOGY Peers /Leechers– A node or computer that does not have the complete file Seed or seeder - A computer with a complete copy of a BitTorrent file Swarm - A group of computers simultaneously sending (uploading) or receiving (downloading) the same file .torrent - A pointer file that directs your computer to the file you want to download Tracker - A server that manages the BitTorrent file-transfer process

14. TERMINOLOGY Share ratio – The ratio is the amount of data a user has uploaded divided by the amount of data they have downloaded for a particular torrent (UL÷DL). Index – An index is, as the name implies, a searchable list of .torrent files, hosted on a website.

15. All peers act as a source Peers exchange different pieces of the file with one another until they assemble a whole As soon as the user has a piece of the file on his machine, he can become a source of that piece to other peers, helping speed download Seed A machine with a complete copy (the seed) can distribute incomplete pieces to multiple peers

16. FACTS BitTorrent is responsible for roughly 27-55% of all internet traffic and 45-78% of world’s P2P traffic all over the globe. As of 2011 BitTorrent has 100 million users and a greater share of network bandwidth than Netflix and Hulu combined. THE PIRATE BAY: Who in September,2008 had 6,912,029 visits & 2,140,240 UNIQUE VISITORS making it 109th most popular website on the internet. Another Popular torrent tracker ISOHUNT claims to have 9857 TERABYTES of files being shared.

17. References http://www.bittorrent.com http://www.wikipedia.org/bittorrent http://computer.howstuffworks.com/bittorrent.htm

18. Questions ??

19. THANK YOU