By kavinyao, Yao
Peer to peer (P2P) computing, which is a specific implementation of distributed computing, has been described as a most promising technology since it can be applied to many fields and it has made great contributions. P2P file sharing, or P2P file exchanging, is one typical application of P2P and one caused great debates as well. In this paper, I will introduce the general theory of P2P file sharing, the features and drawbacks of P2P file sharing and the current situation of piracy via P2P networks. In the end, I will present possible solutions to help solve the piracy problem caused by P2P file sharing.
Part I What is P2P file sharing?
The simplest concept of P2P is: Every client as a server. To be more explicit, we use the term node instead of client to differentiate it from client-server mode, which was in dominant use before P2P file sharing appeared. In client-server mode, if anyone would like to download a file, he/she needs to link to a server where the required file is stored. Since the bandwidth of the server is fixed, large amount of client links will finally lead to lower downloading speed. This is within bearing if the file size is small, but when it comes to large files of several gigabytes, that will cost both time and patience. The P2P network does just the opposite thing! If more people are connected to you, you are expected to get a faster downloading speed. Sounds magic, doesn’t it? But that is solid truth. That is why so many people like to use P2P file sharing. Actually, a P2P file sharing network can be set up using different indexing modes. Here I would like to focus on the pure P2P file sharing system which runs without any centralized control and where the software running at each node is equivalent in functionality. There are just slight differences between these networks compared to the different between P2P and the client-server mode. Now the P2P file sharing technology has developed to the third generation and Bit Torrent and Emule are two typical examples of such technology.
Part II A more efficient way to downloading
As is described above, in a pure P2P file sharing system, each node is equivalent in functionality and if you connect to this kind of system, you will get connected to a certain number of nodes which are connected to even more nodes. Through these nodes, you can search files, query downloading information and link to more nodes quickly and efficiently. The speed of two nodes is usually slow compared with the speed between a client and a server, but since you can download the same file from large number of different nodes simultaneously, you can often get a speed to the maximum of your bandwidth. Besides faster downloading speed you can get, there are other benefits we can get from P2P network, e.g., easy file sharing. Before the appearance of P2P, if people want to share their files, they have to rent a server, store the files on it, connect the server to the Internet and then others can access to the server to get the files. But now P2P saves you all these troubles. You can just select files to make them visible for others to search and if other people are interested in them, they can download them. All these can be accomplished just using P2P software, such as Emule. What’s more, since there is no real server in P2P networks, losing response to one or several nodes does not affect your overall download speed. But in client-server mode, if you lose response of the server, you will have to get started again. Thus, we can conclude that P2P makes file sharing stabler and smoother. People will not be blind to such a fascinating technology. Since 2000, P2P downloading has had a boom and in 2006, the total P2P bandwidth could occupy 50%-70% of total Internet bandwidth.
Part III P2P does do evil
With faster and stabler downloading, you may consider that P2P file sharing as the best way to downloading...