Report: Five models for P2P

Peer-to-peer technology represents a shift of control, in both the architectural and operational senses, from centralized Web services to distributed ones, according to Gartner Inc.'s "The Five Peer-to-Peer Models: Toward the New Web."

The Gartner report lists the five P2P models as:

* Atomistic. Clients make contact using known network addresses or via broadcast announcements. This model needs no server capability, but it assumes bandwidth is readily available.

* User-centered. Clients rely on a directory of users administered by a third party to make contact. Instant messaging is an example of this type of application.

* Data-centered. Data held on users' devices — desktop or portable — is dynamically indexed and made available to others when users connect with one another. Distributed file systems are based on this model.

*Computer-centered. Complex, nonsequential tasks are distributed via the Internet and executed by multiple, low-cost clients. The results of these calculations are reassembled into a meaningful whole at the location from which they were dispatched. For example, the SETI@home project uses the processing power of millions of PCs — when they would otherwise be idle — to analyze data related to the search for extraterrestrial intelligence.

* Web Mk 2. In this model, the preceding functions will converge with current Web architectures and infrastructure.

The FedStats Interagency Task Force is using a data-centered model to enable more than 70 agencies to share statistical information with one another other and with the public, and the Defense Department is investigating atomistic and user-centered systems to provide soldiers with increased situational awareness on the battlefield.