BitTorrent is a peer-to-peer file sharing protocol used to distribute large amounts of data. A user can obtain multiple files simultaneously without any considerable loss of the transfer rate .
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1. BitTorrent
Presented By :Seminar Guide:
Ashish KumarMs. Preetha M Kurup
Roll no.: 17
Cs A
2. Contents:
Introduction
Working of BitTorrent
Terminology
Architecture of bitTorrent
Simple example
Conclusion
References
3. Introduction
BitTorrent is a peer to peer communication protocol for file
sharing.
The data to be shared is divided into many equal sized portions
called pieces.
Each piece is further sub-divided into equal-sized sub-pieces
called blocks.
All clients interested in sharing the same data are grouped into a
swarm.
It does not require a user to download a file completely from a
single server.
4. Introduction
Instead a file can be downloaded from many such users who are
indeed downloading the same file.
A user who has the complete file, called the seed will initiate the
download by transferring pieces of file to the users.
Once a user has some considerable number of such pieces of a file
then even he can start sharing them with other users who are yet to
receive those pieces.
Pieces are not downloaded in sequential order.
5. Introduction
This concept enables a client not to depend on a server completely
.
It also reduces the overall load on the server.
6. Terminology
Torrent : refers to the small metadata file you receive from the
web server.
Peer : A peer is another computer on the internet that you connect
to and transfer data.
Leech: peer thats downloading the file
Seed: A computer that has a complete copy of a certain
torrent.
Swarm: The group of machines that are collectively connected for a
particular file.
7. Terminology
Tracker : A server on the Internet that acts to coordinate the
action of BitTorrent clients. The clients are in constant touch
with this server to know about the peers in the swarm.
Share ratio : This is ratio of amount of a file downloaded to that
of uploaded.
Choked: It is a state of an uploader where he does not want to send
anything on his link. In such cases, the connection is said to be
choked.
8. Swarm -snapshot
9. Working of BitTorrent
BitTorrent protocol shares data through what are known as
torrents.
For a torrent to be alive or active it must have several key
components to function.
These components include a tracker server, a .torrent file, a web
server where the .torrent file is stored and a complete copy of the
file being exchanged.
The first step in the BitTorrent exchange occurs when a peer
downloads a .torrent file from a server.
10. Working of BitTorrent
The role of .torrent files is to provide the metadata that allows
the protocol to function.
The .torrent files contains :