BitTorrent peers in a swarm

The following short video clips illustrate how Vuze Azureus, a popular BitTorrent client, utilizes the BitTorrent protocol to allows individual users, known as peers, to distribute data among themselves by exchanging pieces of the file with each other to eventually obtain a whole copy of the file.

Each peer is shown as an unique IP address with geographic details (country code and its flag). The more peers participate in the file distribution, the faster the transfer speed. Peers who have the complete copy of the file are called seeders. Others are called leechers. If the client software used is known, its version is displayed along with the IP address such as BitComet, Transmission, uTorrent, etc. The state of connection and the transfer speed of each peer is shown.

Vuze can search for torrents of new contents from two major DHT networks: the mainline DHT (approximately 4 million peers in the video clip) can have as many as 100 million peers at certain time during the day, and the smaller Vuze DHT (approximately 300K peers.

When using the BitTorrent protocol, every peer simultaneously receives information from and transfers information to one another. A swarm is a group of peers involved in downloading or distributing a particular file. A tracker is a server which stores a list of peers in a swarm. Each swarm is unique to a particular file. The video clip shows the downloading peer actively receives 6% of its new contents from ten different peers. Not all peers have the complete file. The piece map illustrates that each file segment does not have to be transferred in any particular order.