Peer to peer

Peer to peer is a network model in which all the nodes (peers) interact with each other directly. There is no central server involved to handle the requests.

P2P is in contrast to Client-server in which there are clearly defined roles for client and server.

An example of p2p organization of nodes

Nodes can be organized in any topology but the real essence od peer to peer systems is that there is no central service provider involved but peers interact with each other on equality basis. It has its pros and cons.

Introduction:

Peer to peer systems are those systems which take advantage of storage, cycles, human presence or content available at the end systems of the internet while overlay networks are termed as those networks that are constructed on top of other networks e.g. IP. So peer-to-peer overlay network is a network which is created by the internet peers in the application layer on top of the IP network. In these types of systems the end nodes/systems share their resources such as processing power, network bandwidth and memory storage among themselves to accomplish a set of common tasks in a distributive manner without need of any central coordination system. These systems are self-organized. All peers organize themselves into an application layer on top of IP layer. These are highly scalable and have the capability to grow accordingly with utilization. End systems empowers each other as the consumers are also provider of their resources at the same time. P2P overlay networks are highly reliable too as there is no single point of failure and redundant overlay links ensures availability if a single link got damage or disconnected. These systems are easy to deploy because they are self-organized and there is no need to deploy any server. Now a days peer to peer networks are being used in many ways. Some of them are P2P file sharing applications like Napster, Gnutella, Kaza, Emule, Edonkey, Bittorent etc., media streaming, Grid computing, community networks, instant messaging systems, online chat networks and a very interesting use is Bitcoin a peer-to-peer based digital currency. In peer-to-peer overlay systems there is symmetry in roles where every nodes is client and a server at the same time.

P2P Basic Principle:

The main concept of the p2p and its characteristics are;

– Self-organizing, no central management

– Resource sharing, e.g., files

– Based on voluntary collaboration

– Peers in P2P are all equal (more or less)

– Large number of peers in the network

Definition of P2P:

A P2P system exhibits the following characteristics:

1. High degree of autonomy from central servers

2. Exploits resources at the edge of the network

3. Individual nodes have intermittent connectivity

• No strict requirements, instead typical characteristics