After the Napster decision. file-sharing programs largely moved away from the central-server model. Many of the newer programs used the FastTrack protocol, which uses a two-tiered system consisting of “super nodes” and ordinary nodes rather than a central server. Each node consists of an individual user’s computer.
“Super nodes” essentially perform the directory role that the centralized server provided in the original Napster architecture. Using the file-sharing software, an ordinary node connects to a super node and sends a query for a file, and then the super node checks its index of files and sends the ordinary node a list of any matches. The user can then click on a match to establish a direct peer-to-peer connection and obtain the file from the selected peer.
- ↑ The FastTrack protocol supported a number of different P2P file-sharing programs, including KaZaA and Grokster. Other protocols included Gnutella and eDonkey.
- ↑ A user’s computer may be selected by the software to serve as a super node automatically, based on its storage capacity and/or connection speed, for example.
- ↑ The super node also can forward the query to other super nodes, and send any responses it receives back to the user.