This document provides an overview of the BitTorrent protocol. It describes how BitTorrent works by breaking files into pieces that can be downloaded simultaneously from multiple users, reducing load on servers. Key components are explained, including torrent files, trackers, peers, seeders and leechers. Advantages of BitTorrent include faster download speeds and reduced bandwidth usage. Limitations include potential slow speeds until more peers join and a reliance on trackers.

1. BIT TORRENT PROTOCOL
MILAN VARIA (131113107022)
NIRMA UNIVERSITY,AHMEDABAD

2. Outlines of the Bit Torrent
 What is Bit Torrent ?
 Origin ?
 Why Bit Torrent ?
 Sharing files ?
 Components of Bit Torrent protocol ?
 Installation of Torrent Client and Downloading
Torrents?
 Advantages ?
 Limitations ?
 Conclusion ?

3. Understanding
Bit Torrent Protocol
Bit Torrent Protocol

4. Understanding
 Bit Torrent - Bit Torrent is a Client or a
software that runs on your computer, and it
allows you to download different types of data
from the internet
Ex. Movies , Videos , Audio , Software , OS
etc…
 Protocol – protocol is a set of rules and
convention that governs a particular aspects
on a devices for the network communicate
Ex. Chinese – Indian

5. What is Bit Torrent Protocol ??

6. Introduction
 Bit Torrent protocol is a peer-to-peer file
sharing protocol used for distributing large amounts
of data over the Internet.
 It works on Tit- for-Tat strategy.
 One of the most common protocols for transferring
large files. It makes 40% of traffic on the internet.

7. Introduction
 Increase transfer speeds by breaking down a
large file into small pieces
 Allows the user to download each tiny piece from
different clients.
 Bit Torrent quickly replicate a single large file to a
set of clients.
 It gives files to the other client to share it.

8. ORIGIN (CREATION)
 Bram Cohen designed the protocol in April
2001
 First available version on July 2, 2001
 It is now maintained by Cohen's company “Bit
Torrent”
 As of January 2012, Bit Torrent has 150 million
active monthly users

9. ORIGIN
 Bit Torrent has more active users
than YouTube and Facebook combined.
Bram Cohen

10. Why Bit Torrent ??

11. Concept of Client-server
downloading
 Loads between servers and clients
 It works like this :
1) You open a Web page and click a link
to download a file.
2) File is download from server to client.
3) The transfer is handled by a protocol (a
set of rules), such as FTP (File Transfer
Protocol) or HTTP (Hypertext
Transfer Protocol).

12. CLIENT SERVER
ARCHITECTURE

13. DRAWBACK OF CLIENT-
SERVER
 More client more load on server
 It lacks the robustness of a P2P network.
 If server fail, client’s requests can’t be fulfilled.
Ex. E-commerce Flipkart’s server Crashed two
times Because of traffic of users wanted to buy
Xiaomi Mi3 cell phone

14. Peer To Peer Network
 In P2P networks, resources are distributed
among many nodes.
 All nodes works as a service
requester as well as service
provider
 No load on central devices

15. Roles of Torrent (Torrent Lingo)
 TORRENT
 BIT TORRENT CLIENT
 PEER
 SEEDER
 LEECHER
 SWARM
 TRACKER
 INDEX

16. CONT…
 Torrent – To share a file a peer first
creates a .torrent file, a small file that
contains…
(1) metadata about the files to be shared, and
(2) Information about the tracker,(the computer
that coordinates the file distribution)
 The URL of the tracker
 Pieces <hash1, hash 2,…, hash n>
 Piece length
 Name of the file
 Length of the file

17. CONT…
 Peers first obtain a .torrent file, and then connect
to the specified tracker, which tells them from
which other peers to download the pieces of the
file.
 Bit Torrent client – It is a piece of software which
takes the .torrent file, reads the information in it
and starts the download.
 Peers- A peer is any computer participating in the
download and upload of a torrent file
 Seeder
 leecher

18. CONT…
 Seeders - A seed (or seeder) is anyone who
has a complete copy of the file being shared
across the torrent network.
 Leechers - A leech (or a leecher) is the person
who does not have the complete file yet but
has joined the network to download it.
 A leecher becomes a seeder when he downloads
the entire file and then shares it across the
network.

19. CONT…
 Swarm – The swarm is the sum total of all the
leechers and seeders (i.e. Group of all the
computers) participating in the torrent process.
 Index – An index is a searchable list of
.torrent files, hosted on a website.
 Tracker – The tracker is a server which has
the information of who has what files and who
needs which ones, thus acting as a bridge
between seeders and leechers. (Ex. Land
Brokers)
 IP address, port, peer id
 State information (Completed or Downloading)
 Returns a random list of peers

20. How file sharing works in bit torrent
?

21. File Sharing
 Whenever seeder uploads the file then large
files are broken into pieces of size between
 16 KB to 16 MB (In latest client)
1 2 3 4 5 6 7 8

22. File Sharing (Example)
Data or a file with 5 pieces
1 2 3 4 5

23. CONT…

24. CONT…
1
4

25. CONT…
1
2
4

26. CONT…
1
3
5
4

27. CONT…
2
3
5

28. CONT…
3
5
2

29. CONT…
All are
seeder

30. CONT…
 After downloading, it become the sources for
further downloads.
 Tracker selects Random peers – Random
loads

31. BIT TORRENT PROTOCOL
 1. Seeder
generates a
torrent file
 Uploads
torrent to a
web server.

32. BIT TORRENT PROTOCOL
 2. The
seeder
notifies the
tracker that
it is sharing
the file
described in
the .torrent
file.

33. BIT TORRENT PROTOCOL
 3. A leecher
downloads
the .torrent
file from the
web server.

34. BIT TORRENT PROTOCOL
 The leecher
connects to
the tracker
specified in
the .torrent
file.
 The tracker
returns a list
of other
peers who
are sharing
the file.

35. BIT TORRENT PROTOCOL
 5. The
leecher
connects
to its peers
to
download
pieces of
the files.

37. CONT…
 By downloading multiple pieces at the same
time, the overall speed is greatly improved.
 The more computers involved in the swarm, so
the file transfer is faster because there are
more sources of each piece of the file.

38. Downloading And Installation
Of Bit Torrent Software
(screenshots)

46. 9

50. Advantages
 Open-source program offers free installation.
 Share large amounts of data in a short time.
 Easy to download, do not require high knowledge.
 Increase the source of download to reduce
bandwidth.
 Load divided between peers.
 Allows to download different pieces at the same
time.

51. Limitations
 Slow start and finish
 Central tracker can be a bottleneck.
 Requires the complex knowledge of
distribution across the network to upload.

52. Conclusion
 Study indicates that Bit Torrent traffics more
than 40% of the total network traffic.
 Swarming is an efficient way to speed up
downloads

53. THANK
YOU

54. Any Question ??