| Peer to Peer (P2P) Technology- How it works: | | | | allowing search requests to move through the |
| Ever wondered how P2P works? This guide will | | | | network very quickly. Peers then establish a direct |
| run down most of the major P2P services and | | | | connection to a client after a file has been found. |
| how they work. Peer to Peer technology lets | | | | Advantages: Any client can become a supernode. |
| people share files over a network on the internet. | | | | Disadvantages: Corruption of files occur. |
| Most people now use what is known as the | | | | Clients include: Kazaa ( iMesh ( |
| second generation of P2P, which is unlike its | | | | BitTorrent: .torrent files are used to store |
| predecessors like such as Napter, the second | | | | information about the file being shared. Once a |
| generation has no centralized server, making it | | | | torrent file is opened, the client connects to the |
| harder for it to shut down. | | | | tracker which tells the client where the file is |
| How first generation P2P services worked: | | | | located and what other peers/seeders there are. |
| A connection is established by a peer finding | | | | BitTorrent works by chunks of small files being |
| another peer to connect to. Each peer exchanges | | | | transferred (even through multiple connections), |
| active peer and their addresses. When a | | | | while you are downloading. The files are checked |
| connection has been established, the user can | | | | for corruption as the download continues. |
| then search for files. When a search has been | | | | Leechers are people who download and don't |
| submitted, it connects to all nodes on its | | | | upload, and are highly frowned upon on some |
| connection list. The results are then displayed and | | | | sites, disallowing them from downloading any |
| a connection is made. | | | | further. |
| How second generation P2P services worked: | | | | Advantages: Very fast for popular, new files. |
| Gnutella2: Hubs are used to quickly search for | | | | Disadvantages: Trackers are unreliable and if it |
| files, eliminating the original "find peer and search" | | | | goes down, the file is lost. |
| method. Instead, they store a list of files on all | | | | Clients include: Azureus ( Shareaza ( |
| the "Leaves" (A peer) that are connected to it, | | | | EDonkey Network: Edonkey runs on the same |
| thus dramatically reducing search time. | | | | principle as first generation P2P, only anybody can |
| Advantages: Unlike Napster, if a hub crashes, it's | | | | become a server. Clients communicate with the |
| network stays alive. | | | | server to download files, and random chunks can |
| Disadvantages: Doesn't make network any more | | | | be downloaded in any order then put together in |
| durable than the first generation of P2P. | | | | the end. |
| Gnutella2: | | | | Advantages: No file corruption, leech penalization. |
| FastTrack: Programs such as Kazaa and iMesh | | | | Disadvantages: It can penalize users unfairly. |
| use the FastTrack protocol. Normal peers connect | | | | EDonkey: |
| to a supernode which acts jsut like a hub. | | | | Infinitive!, Copyright 2005. |
| Supernodes also connect to other supernodes, | | | | |