It is the abbreviation of peer-to-peer (as if you have seen the article is Point to Point, I don't know, the online information is not clear, depressed), Peer has "(status, ability, etc.) in English "" Colleagues "and" partners "and so on. In this way, P2P can also be understood as the meaning of "partners' partners", or is called peerless networking. At present, it is believed that it has a high future in strengthening communication, document exchange, distribution calculation, etc.
Today's Internet is facing a revolution. This revolution is working hard to change the basic characteristics of the Internet. This is the terminal (or client) of the network, such as desktop computers, mobile phones, and PDAs, etc., are required to end with server-dominated Internet. This is P2P.
P2P is a model of a network. Its basic concept is that any node can be used as a server or client. Traditional client / server networks have predefined customers and server nodes, while P2P is different, and P2P can provide some additional characteristics, and these features are unable to use traditional models. P2P: Overview Today's most common distribution calculation model is a client / server model. Figure 1 depicts a typical client / server architecture.
In the client / server system, the customer request service, the server is served. On today's Internet, there is a large number of servers --Web servers, mail servers, FTP servers, and more. The client / server system is an example of a centralization system, and the entire network relies on the central node and the named server to provide services. If there is no server, the network will be meaningless; if there is no, how do Web browses work? Regardless of the number of clients or browsers, the network can only be meaningful under the premise of the server.
Similar to the client / server system, P2P is also a distributed computing model, but there is a large difference, P2P is a non-centralized system (as shown in Figure 2), and there is no customer or server in the network. Each entity in the network is equally, with the same state, which means that an entity can request a service (the client's characteristics) or provide a service (the characteristics of the server). Figure 2 shows a P2P network.
Although each node has the same state in the network, they don't require the same physical properties. A P2P network can contain nodes with different performance, by the mobile device to the mainframe. For a mobile device, it may not be used as a server due to its own restrictions, but from the network, there is no limit.
Both network models have their own advantages and disadvantages. You can see by the client / server network of Figure 1, and when the network increases (ie, more and more customers join), the greater the pressure of the central server. When plus a customer, the performance of the central node will weaken; and its failure will lead to the paralysis of the entire network.
For P2P networks, the situation is completely different. Since each entity (or node) in the network is active participant, each node provides some resources for the network, such as storage space or CPU. When more and more nodes join the network, the performance of the network will grow. Therefore, its performance will also be enhanced when the network increases. You will not touch the extension problem in the client / server system.
There is also a big difference in the P2P network and client / server model: even if only one node is active, the P2P network is also considered active. The P2P network is not available when there is no node.
However, the gold is not enough, although the P2P network has these advantages, but you have to pay some cost. First, manage such a network may be a nightmare, and in the client / server network, you only need to manage the central node. Therefore, the P2P network is complex whether the P2P network is complex in terms of security strategies and backup strategies. Second, the P2P protocol requires more "interaction" than the traditional client / server protocol, such as the node joins or exits the network. These aspects will have some effects on performance. The following tries to reveal the impact of P2P with three sentences:
Peer-to-peer is the end of the read-only web)
Peer-to-peer allows you to participate in the Internet Again
Peer-to-Peer Steering The Internet Away from TV TV, as described above, P2P is not a new idea, from some angles, it is even the most basic idea of the entire initial creation. We will wish to spend a little time.
What can P2P?
The distribution of P2P is a distribution of the Internet, and the sharing spirit has brought unlimited imagination. It is believed that at least 100 applications can be developed, but from the current application, P2P's power is mainly reflected in a wide range of sharing, search Advantage. In this regard, it is mainly caused, or it is better to solve the four types of applications on the network: peer calculations, collaborative work, search engines, file exchange.
P2P Related Resource Links
Anorel network P2P topic: http://www.yesky.com/20010926/198947.shtml more to search engine search !!
