Introduction to BitTorrent.

BitTorrent was created by Bram Cohen as a way to distribute large files around a network. The new way to file share has grown exponentially over the past 5 years especially for users who want to distribute large files over the internet. For example, if you had a 1GB file and there was 300 people trying to download it, it would take a lot of time to distribute 300GB of data for most people. So instead, you distribute the file in small pieces to users who then share them around with other users until they have the full file. After they have the full file they can continue to upload to other users to help them also get the full file, this is known as seeding, and we will go more in depth on that later. A large commercial site could also use BitTorrent to spread updates for their software to cut back on bandwidth costs. The speed of BitTorrent can be absolutely amazing, with very large files transferring in a few minutes, depending on your connection. Several sites have been setup to distribute pirated content across the Internet and as usual, groups such as the MPAA are quick to blame the technology and not those who use it for piracy. However, BitTorrent is not an evil creation by a rampant pirate, it was a development by Bram to help distribute content quicker around an unreliable network. Its use should be embraced by websites all over the world and Bram should be praised for it.

Torrent Files

BitTorrent is not like P2P networks such as eD2K or FastTrack,as most clients do not allow you to search for the actual files through the client. Instead you go to websites, otherwise known as trackers that list torrent files. Those file will have all the information necessary for what you want to download as well as information to send back to the tracker. The tracker is like the central server, that keeps information on each user currently currently sharing the files, and what part of the files they have. Once you download a torrent file, your BitTorrent client (eg. Vuze, uTorrent, Bitcomet, BitTornado, etc.) should launch immediately and connect to the tracker. The tracker then connects you to seeds and peers who are sharing the file and your download should start. Once you have at least one bit of the file, you will start uploading that bit to other users who don't yet have it. So there we see how BitTorrent is different from other P2P networks, all it needs is the torrent file for the files (or folders) that you wish to download and share and then it does the sharing work for you.


BitTorrent trackers are like P2P servers.

When you open a .torrent file your BitTorrent client connects to a tracker from which it gets information on peers currently uploading and downloading files. It keeps track of the parts of the files that the users have. This information is very useful because it will give you an accurate number of Seeders and Leechers currently sharing using a particular torrent.

Most of the best torrent sites around now keep the pages updated with information from the tracker so users can know if a tracker is still alive (all parts are available) or is dead (not all parts are available, it is incomplete).

Development and research on "trackerless BitTorrent" continues as many see BitTorrent trackers as "centralised distribution points". This makes them an easy target for litigation if users of that tracker are sharing copyrighted content.

Seeds, Peers and Leechers

These three terms are very important. They all represent users who are currently using BitTorrent to share files or folders.

Seeding is the term for when you have completed downloading a torrent or a piece of a torrent and are now completely sharing by uploading that data to other users who are downloading the same file.

Most private torrent sites (site you need to register with) require that you keep a 1:1 (download:upload) ratio, to remain in good standing, and that is only done by seeding the file or files after you are done completely downloading them.

In public torrent websites (registration not necessary), many users do not feel the need to seed and therefore other users suffer slow download times. Seeding is the foundation of torrent downloading.

Leechers, on the other hand, will download the data offered, and not share their upload with the rest of the community to benefit the entire swarm. A leech can also mean someone who does not possess the entire file that is being offered. Therefore, all BitTorrent downloaders are leechers and once they have the completed file, should they choose to leave their BitTorrent client connected, they then graduate to a seeder. The negative sense of this term comes to play when the downloader disconnects as soon as they are done downloading the file.

Torrent Listing Sites

These links have been removed as we are not affiliated with torrent trackers but Google can help you :)

The importance of Uploading

I had to write a small bit about uploading. Uploading on BitTorrent is vital. If you connect to a torrent that has just 3 seeds and 800 peers, then most of the sharing will be done between peers. If you download the whole file and have uploaded just 10% of that file and then leave, you are hurting the performance of that torrent. This kind of usage is very bad because if a lot of people begun doing it, then there would be very little seeds and eventually the seeds could disappear and there may be nobody left with 100% of the file. The full file still may be available as files are traded in small pieces, but if all users stopped uploading as much as they downloaded, torrents life wouldn't last long and when it was fully working, it would be very slow. Always make sure you upload as much as you download if not more. Someone who download 700MB and uploads 700MB still in the eyes of BitTorrent is not sharing properly. For the life of a torrent to go on for a long time at high speeds, all users should make sure they upload at least 150% of what they downloaded. When your torrents are done downloading keep them active until you reach this amount, or if you need to use the files, you can stop the torrent activity, use them (but do not alter them) and then click the same torrent again and you would be added to the tracker as a seed and would continue uploading again. Trackers has begun banning leechers, or keeping records of leechers as a way to deter their behavior, if you like BitTorrent, don't try and cheat it.

Table of Contents

  1. 1. Introduction and Requirements
  2. 2. Introduction to BitTorrent
  3. 3. Introduction to uTorrent
Written by: Andre Yoskowitz