P2P Applications

Peer to Peer Applications (P2P)

There is various application which helps to share information between the systems. “Peer-to-peer is a method or application of structuring distributed applications in a network such that the individual nodes have symmetrical roles. Instead of dividing the system into client and server in P2P applications a node may act as both a client and a server.An example of pure P2P application is Gnutella- an open source, P2P File Sharing Application. Due to decentralized nature, P2P applications are very difficult to manage. Many Applications like Napster, bit torrent, uTorrent etc. are Hybrid of server-client and P2P architecture.

Peer-to-peer (P2P) computing or networking is a distributed application architecture that divides the available tasks or workloads between peers present in the system. Peers are equally privileged, equivalent role of participants in the application. They are said to form a peer-to-peer network of nodes.

The Peers of the system make a portion (components) of their available resources, such as processing power, disk storage or network bandwidth, that are directly available to other network participants, without the need for central coordination by servers or stable hosts as the peers behave as both servers as well as the client.Peers are both consumer and suppliers whereas client and server are distinct function and rights. Emerging collaborative P2P systems are going beyond the era of peers as doing the similar tasks while sharing resources and are looking for diverse peers. Those diverse peers can possess the unique character, capabilities and resources. Such feature is widely accepted in the virtual community thereby empowering it to engage in greater tasks beyond those that can be accomplished by individual peers, as a result it can benefit to all the peers of the system.

In the above figure:

1. Query message sent over existing TCP connections
2. peers forward Query message
3. Query Hit sent over reverse path

1. focus: decentralized method of searching for files
2. each application instance serves to:
   1. store the selected files
   2. route queries (file searches which provide the direction) to its neighboring peers
   3. respond to queries (server file) if the file stored locally

Scalability:

1. limited scope
2. flooding

References:

1. A.S. Tanenbaum, “Computer Networks”, 3rd Edition, Prentice Hall India, 1997.
2. W. Stallings, “Data and Computer Communication”, Macmillan Press, 1989.
3. Kurose Ross, “Computer Networking: A top-down approach”, 2nd Edition, Pearson Education
4. Larry L. Peterson, Bruce S. Davie, “Computer Networks: A Systems Approach”, 3rd Edition, Morgan Kaufmann Publishers