BitTorrent is a protocol which is based on P2P networks category.. A Brief Presentation on BitTorrent and what Revolution it has brought.

1. BitTorrent – A revolution
in P2P networking
Mihir Jyoti Chakrabarti, Arijit Roy, Anirban
Sen
27 11 06
Swami Vivekananda Institute of Science and
Technology

2. Introduction
WHAT IS P2P NETWORKING?
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3. Client/Server Architecture
 What is it?
 Client sends request, server provides the client with
data.
 Server is the only data source.
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4. Client/Server Architecture
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 Problems
 Scalability: how many users can a server support?
 What happens when user traffic overload servers?
 Limited resources (bandwidth, CPU, storage)
 Reliability: if number of servers is small, what happens
when they break, fail, get disconnected, are
mismanaged by humans?
 Efficiency: if your users are spread across the entire
globe, how do you make sure you answer their
requests quickly?

5. The Alternative: Peer-to-Peer
 A simple idea
 Provides as well as consumes network services.
 A cooperative model: clients = peers = servers
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A
B E
DC

6. Peer to Peer
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 The benefits
 Scalability: Number of “servers” grows with users
 BYOR: bring your own resources (storage, CPU, B/W)
 Reliability: load spread across many peers
 Probability of them all failing is very low…
 Efficiency: peers are distributed
 Peers can try and get service from nearby peers

7. Types of P2P programs
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 Centralized
 In a centralized system a server maintains directories
of what is stored in each peer computer. The central
server directs the connections between peers.
 Example Napster , Maze etc

8. Types of P2P programs
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 De-Centralized
 With a decentralized program each peer connect
directly to other peers without being directed by a
server. This connection is repeated making the
resulting network large.
 Example: Gnutella

9. What is BitTorrent
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 Programmer Bram Cohen designed the protocol in
April 2001 and released its first implementation of
the BitTorrent client on 2 July 2001.
 Protocol for the practice of peer-to-peer file sharing
 Designed for fast, efficient content distribution
 Ideal for large files, e.g. movies, DVDs, ISOs, etc.
 Not a full fledged P2P system
 Does not support searching for files

10. Important Terminology
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 .torrent – Metadata file containing information(size,
about) about file to be shared via BitTorrent.
 Share Ratio – The ratio of the amount of data you've
uploaded to the amount of data you've downloaded.
 Peer – One instance of a BitTorrent client running on a
computer connected to the Internet to which other clients
connect and transfer data.
 Seeder – A peer who has a complete copy of the torrent
and offers it for upload.

11. Important Terminology
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 Leech – Usually a peer who has a negative effect on
the swarm by having a very poor share ratio - in other
words, downloading much more than they upload.
 Swarm – Together, all peers (including seeders) sharing
a torrent. For example, six ordinary peers and
two seeders make a swarm of eight.
 Tracker – A tracker is a server that keeps track of which
seeds and peers are in the swarm. The tracker is not
directly involved in the data transfer and does not have a
copy of the file.
 Piece – This refers to the torrent files being divided up
into equal specific sized pieces (i.e. 512Kb, 1Mb).

12. Sharing Pieces
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Initial Seeder
1 2 3 4 5 6 7 8
Peer
1 2 3
Peer
54 76 8 1 2 3 54 76 8
Seeder Seeder

13. Working of BitTorrent
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Tracker
Swarm
Leechers
Seeder

14. The Beauty of BitTorrent
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 More seeders = more availability of the full file
 Great for content distribution
 More peers = more replicas of pieces
 More replicas = faster downloads
 Multiple sources for each piece

15. Screenshot of a BitTorrent Client
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16. History of BitTorrent
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 Bram Cohen (born October 12, 1975) created the
first file sharing program to use the protocol, also
known as BitTorrent.
 Prior to version 6.0, BitTorrent was written in Python,
and was free software. Very early versions released
prior to December 30, 2001 were released into
the public domain without a license. Versions up to and
including 3.4.2 were distributed under the MIT license.
 Since version 6.0, the BitTorrent client has been a
rebranded version of µTorrent. As a result, it is no
longer open source.

17. BitTorrent Revolution
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18. BitTorrent Revolution
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19. 19
WHAT IS LEGAL AND
ILLEGAL?

20. Illegal Events
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 Finland: Finreactor
 Hong Kong: Individual actions
 Singapore: Odex actions against users
 Slovenia: Suprnova
 Sweden: Pirate Bay
 TorrentSpy

21. Conclusion
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 One thing for sure, torrent is not equal to piracy.
 The torrent protocol is just a transmission mean
for users to download files more easily.
 It is the content (not the protocol) that makes the
act illegal. When it comes to downloading through
the torrent protocol, there’s no real way to stay
completely safe.
 However, it remains one of the most effective peer-
to-peer protocols in the world. If you’re worried that
you may be downloading something that’s against
the laws in your country, follow your moralistic
instinct.

22. Reference
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 http://en.wikipedia.org
 http://www.google.co.in
 http://www.krazytech.com
 http://www.slideshare.net
 http://blog.seattlepi.com/timothymccormack/2013/0
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 http://historycomputer.com/Internet/Conquering/Bit
Torrent.html
 http://www.youtube.com
 http://www.bittorrent.com

23. Clear Your Doubts
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