Peer-to-peer (P2P) – is the peer decentralized computer network. It is based on the equal rights of all participants. Such a structure makes the network more secure, as there is no possibility to block off its separate servers – all the participants of the network are both servers and clients. The blockchain technology is built on the basis of the P2P network.
Although the P2P systems were previously used in many areas of apps, the architecture was popularized by the file exchanging system Napster, released in 1999. This conception inspired new structures and philosophies in many areas of the human interaction.
Partially decentralized networks
In addition to pure peer-to-peer networks, there are so-called hybrid networks in which there are servers used to coordinate the operation, search or provide information about existing network machines and their status (online, offline, etc.). Hybrid networks combine the speed of centralized networks and the reliability of decentralized networks thanks to hybrid schemes with independent index servers that synchronize information with each other. If one or more servers fail, the network continues to function. Partially decentralized networks include, for example, eDonkey, BitTorrent, Direct Connect, The Onion Router.
P2P Technology Review
In the peer-to-peer network, the tasks or workload are distributed equally among the peer-to-peer networks with equal privileges. Separate nodes provide all network participants with a part of their resources, such as the computational power, space of the disk storage or the network capacity. At that, there is no need of a centralized coordination by the servers or stable hosts.
This means that, unlike the traditional “client-server” model, separate network nodes carry out both the functions of servers and clients, i.e. are both consumers and suppliers of the network resources. In the first case, a node sends a request for the necessary resources, in the second one – reacts on such request by offering its own resources.
In some cases, in the partially decentralized networks, there are separate servers that coordinate the work of the network as well as provide the information about the valid nodes and their status.
New combined P2P systems look for the solutions, with that the separate network participants offer not the same resources, but the unique ones, which are useful for the whole virtual community. This allows solving more complicated tasks within the network than when all its nodes do the same.
Use of P2P
The peer networks are used for the file-sharing operations. In this case, the user gives an access to the file on his computer to other network participants, acting as a server. The client finds the file and starts downloading it from the computer. The downloading of one file from several sources at once is also possible.
Another use of the peer networks is the distributed computing. In this case, a complicated task is divided into a plenty of small ones that are solved by the network participants, “collecting” the result after that into an entity.