Peer to Peer Networks

Peer-to-Peer networking

A 'peer' is a person who is on the same level of authority and power as you. In a Peer-to-Peer network, there is no computer with more control or authority than any other. There is no file server, little protection of one workstation against another, no hierarchy of "super users" and "standard users". Any computer can begin a network transaction with any other computer on the network.

Peer-to-Peer networks usually are used in the home or very small organisations with trusted users who want to share files, an Internet connection, or a printer. Without a server, costs are low and installation is simple, but users are vulnerable to each other.

Peer-to-Peer Computing (P2P) is an alternative to the traditional centralized (or client-server) computing model. A centralized model uses server-based sharing and requires an intermediary such as a Web, e-mail, or corporate server. P2P has two or more computers linked for the purpose of sharing information files (locally or remotely) with each taking an equal role in the data-transfer process without a central server.

No server is needed to share information among systems; instead, each user's computer handles the serving. There are, however, flavours of P2P : some models do not use a central server, while others use central servers to hold directories and to direct traffic (but not to store data).

With Gnutella, instead of using a central server, each PC uses a piece of software called a 'servent' to share files ('servent' is a combination of 'server' and 'client'.) On a Gnutella network, a PC notifies a connected PC of its presence. The notified PC then tells the computers it is connected to the first PC, and they in turn inform other members of the network in an expanding series of links. Once the members are aware of a PC, the user can search the contents of the shared directories of the peer network members.The list of matching files travels that path back to the starting computer, which can then open a direct connection with a computer having the matching file and download the file. The Gnutella model can be used for any type of file, not just music.