BitTorrent

Mahesh Mohan M.U, CS4

Outline

What is BitTorrent Protocol?, How it works? Terminologies How to download files using Torrent?

Torrent search sitesTorrent clients

FTP(File Transfer protocol) Client-Server Model Central server store the files Large traffic to the server will lead to download

failure Shortcomings of FTP makes people to think

over traditional FTP

What is BitTorrent?

P2P(Peer To Peer) file transfer protocol Transfer of large files Files are shared by many users Active participation of all users Huge success in file sharing domain since 2003

How it works?

To share the data using BitTorrent we must have:-

Tracker server, a file with .'torrent' extension, complete copy of the file being shared

.torrent file conatins data which is essential for the protocol to function- file length, file name, information about the tracker

When we open .'torrent' file in client, it will connect to the client and start downloading

BitTorrent Network

Terminology

Torrent

Peer

Seed

Tracker

Leecher

Swarm

Torrent

This refers to the small metadata file you receive from the web server (the one that ends in .torrent.) Metadata here means that the file contains information about the data you want to download, not the data itself.

Peer

A peer is another computer on the internet that you connect to and transfer data. Generally a peer does not have the complete file.

Leecher

They are similar to peers in that they won’t have the complete file. But the main difference between the two is that a leech will not upload once the file is downloaded.

Seed

A computer that has a complete copy of a certain torrent. Once a client downloads a file completely, he can continue to upload the file which is called as seeding. This is a good practice in the BitTorrent world since it allows other users to have the file easily.

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.

Swarm

The group of machines that are collectively connected for a particular file.

1. Download the torrent file

2. Contact the tracker

3. Tracker response

4. Peer connection

5. Peer 'A' downloads a piece from the network

6. Piece exchange starts

7. Peers periodically contact tracker

Visualization of the working of BitTorrent

Visualization

Download files using BitTorrent

First download a Torrent client to do us the job of downloading the files

Then, go to a good Torrent search engine Download the file with '.torrent' extension Open it in your client If the download starts with the progress bar

moving, take a deep breath!

BitTorrent Clients

Deluge(http://deluge-torrent.org) Transmission(http://transmissionbt.com) KTorrent(http://ktorrent.org) Vuze(http://azureus.sourceforge.net/) qBittorrent(http://www.qbittorrent.org/)

Deluge in action

Torrent search sites

Legal Torrents Legit Torrents http://torrentz.com http://piratebay.org http://mininova.com

Thanks for hearing me patiently!

Credits

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Thanks Google Picasa for pictures

Questions?