Peer to Peer
"Peer to peer is the relational dynamic at work in distributed networks".
Peer to peer is there not restricted to technology or P2P filesharing as such, but covers every social process with a peer to peer dynamic, whether these peers are humans or computers.
It's a way of organizing, and a way of thinking about organizing. It's also a political and social program for those who believe that in many cases, peer to peer modes are a preferable option.
"What is peer to peer? Here’s a first tentative definition: It is a specific form of relational dynamic, is based on the assumed equipotency of its participants , organized through the free cooperation of equals in view of the performance of a common task, for the creation of a common good, with forms of decision-making and autonomy that are widely distributed throughout the network.
P2P processes are not structureless, but are characterized by dynamic and changing structures which adapt themselves to phase changes. It rules are not derived from an external authority, as in hierarchical systems, but generated from within. . It does not deny ‘authority’, but only fixed forced hierarchy, and therefore accepts authority based on expertise, initiation of the project, etc… P2P may be the first true meritocracy. The treshold for participation is kept as low as possible. Equipotency means that there is no prior formal filtering for participation, but rather that it is the immediate practice of cooperation which determines the expertise and level of participation. Communication is not top-down and based on strictly defined reporting rules, but feedback is systemic, integrated in the protocol of the cooperative system. Techniques of 'participation capture' and other social accounting make automatic cooperation the default scheme of the project. Personal identity becomes partly generated by the contribution to the common project.
P2P is a network, not a hierarchy (though it may have elements of it); it is 'distributed', though it may have elements of centralization and 'decentralisation'; intelligence is not located at any center, but everywhere within the system. Assumed equipotency means that P2P systems start from the premise that ‘it doesn’t know where the needed resource will be located’, it assumes that ‘everybody’ can cooperate, and does not use formal rules in advance to determine its participating members. Equipotency, i.e. the capacity to cooperate, is verified in the process of cooperation itself. Validation of knowledge, acceptance of processes, are determined by the collective. Cooperation must be free, not forced, and not based on neutrality (i.e. the buying of cooperation in a monetary system). It exists to produce something. It enables the widest possible participation. These are a number of characteristics that we can use to describe P2P systems ‘in general’, and in particular as it emerges in the human lifeworld. Whereas participants in hierarchical systems are subject to the panoptism of the select few who control the vast majority, in P2P systems, participants have access to holoptism, the ability for any participant to see the whole. Further on we will examine more in depth characteristics such as de-formalisation, de-institutionalisation, de-commodification, which are also at the heart of P2P processes.
Whereas hierarchical systems are based on creating homogeinity amongst its 'dependent' members, distributed networks using the P2P dynamic regulate the 'interdependent' participants preserving heterogeinity. It is the 'object of cooperation' itself which creates the temporary unity. Culturally, P2P is about unity-in-diversity, it is concrete 'post-Enlightenment' universalism predicated on common projects; while hierarchy is predicated on creating sameness through identification and exclusion, and is associated with the abstract universalism of the Enlightenment.
To have a good understanding of P2P, I suggest the following mental exercise, think about these characteristics, then about their opposites. So doing, the radical innovative nature of P2P springs to mind. Though P2P is related to earlier social modes, those were most in evidence in the early tribal era, and it now emerges in an entirely new context, enabled by technologies that go beyond the barriers of time and space. After the dominance during the last several millennia, of centralized and hierarchical modes of social organisation, it is thus in many ways now a radically innovative emergence, and also reflects a very deep change in the epistemological and ontological paradigms that determine behaviour and worldviews.
An important clarification is that when we say that peer to peer systems have no hierarchy or are not centralized, we do not necessarily mean the complete absence of such characteristics. But in a P2P system, the use of hierarchy and centralization, serve the goal of participation and many-to-many communication, and are not used to prohibit or dominate it. This means that though P2P arises in distributed networks, not all distributed networks exhibit P2P processes. Many distributed bottom-up processes, such as the swarming behaviour of insects, of the behaviour of buyers and sellers in market, are not true P2P processes, to the degree that they lack holoptism, and do not promote participation. P2P, as a uniquely human phenomenom integrates moral and intentional aspects. When distributed meshworks, for example interlinking boards of directors , serve a hierarchy of wealth and power, and are based on exclusion rather than participation, this does not quality as a full P2P process.
P2P can be a partial element of another process; or it can be a full process. For examples, the technological and collaborative infrastructure build around P2P principles, may enable non-P2P processes. In the example just above it is the infrastructure of Empire, but it can also enables new types of marketplaces , gift/sharing economy practices. Where P2P is a full process, we will argue that it is a form of communal shareholding producing a new type of Commons."
From a Computer Science Perspective
"Generally, a peer-to-peer (or P2P) computer network refers to any network that does not have fixed clients and servers, but a number of autonomous peer nodes that function as both clients and servers to the other nodes on the network. This model of network arrangement is contrasted with the client-server model (that was unable to scale up to today's necessities). In the P2P model any node should be able to initiate or complete any supported transaction. Peer nodes may differ in local configuration, processing speed, network bandwidth, and storage quantity. This is the basic definition any p2p system.
The term P2P may mean different thing to different people in different contexts. For instance, although the term has been applied to Usenet and IRC in all their incarnations and is even applicable to the network of IP hosts known as the Internet, it is most often used restricted to the networks of peers developed starting in the late 1990s characterized by transmission of data upon the receiver's request instead of the sender's. Such early networks included Gnutella, FastTrack, and the now-defunct Napster which all provide facilities for free (and somewhat anonymous) file transfer between personal computers connected in a dynamic and unreliable way to a network in order to work collectively towards a shared objective.
Even those early Networks did work around the same concept or implementation. In some Networks, such as Napster, OpenNap or IRC, the client-server structure is used for some tasks (e.g. searching) and a peer-to-peer structure for others, and even that is not consistent in each. Networks such as Gnutella or Freenet, use a peer-to-peer structure for all purposes and are sometimes referred to as true peer-to-peer networks, even though some of the last evolution are now making them into a hybrid approach were each peer is not equal in its functions.
When the term peer-to-peer was used to describe the Napster network, it implied that the peer protocol nature was important, but in reality the great achievement of Napster was the empowerment of the peers (ie, the fringes of the network). The peer protocol was just a common way to achieve this.
So the best approach will be to define peer-to-peer, not as a set of strict definitions but to extend it to a definition of a technical/social/cultural movement, that attempts to provide a decentralized, dynamic and self regulated structure (in direct opposition to the old model o central control or server-client model, that failed to scale up to today's expectations), with the objective of providing content and services. In this way a computer programs/protocol that attempts to escape the need to use a central servers/repository and aims to empower or provide a similar level of service/access to a collection of similar computers can be referred to as being a P2P implementation, and it will be in fact enabling everyone to be a creator/provider, not only a consumer. Every P2P system is by definition self feeding, the more participants it has the better it will satisfy it's objectives.
Technically, a true peer-to-peer application must implement only peering protocols that do not recognize the concepts of "server" and "client". Such pure peer applications and networks are rare. Most networks and applications described as peer-to-peer actually contain or rely on some non-peer elements, such as DNS. Also, real world applications often use multiple protocols and act as client, server, and peer simultaneously, or over time.
P2P under a computer science perspective creates new interesting fields for research not on to the not so recent switch of roles on the networks components, but due to unforeseen benefits and resource optimizations it enables, on network efficiency and stability.
Peer-to-peer systems and applications have attracted a great deal of attention from computer science research; some prominent research projects include the Chord lookup service, the PAST storage utility, and the CoopNet content distribution system (see below for external links related to these projects).
It is also important to notice that the computer is primarily a information devices, whose primary function is to copy data from location to location, even more than performing other types of computations. This makes digital duplication something intrinsic to the normal function of any computer it is impossible to realize the goal of general purpose open computing with any type of copy protection. Enforcement of copyright in the digital era should not be seen as a technical issue but a new reality that society needs to adapt to." (https://en.wikibooks.org/wiki/The_World_of_Peer-to-Peer_%28P2P%29/Print_version)