From ARPANET to Internet: A History of ARPA-Sponsored Computer Networks, 1966-1988

The ARPANET and Internet were pioneering computer networks that established the technical groundwork and social expectations for wide-area networking in the United States today. Created by the U.S. Defense Advanced Research Projects Agency (ARPA), the ARPANET was a testing ground for innovative concepts such as packet switching, distributed topology and routing, and the connection of heterogeneous computer systems. ARPA dealt with the complexities of this project using a management style that fostered collegial interaction and a technical strategy known as "layering" that allowed network components to be developed independently. The highly visible success of the ARPANET brought its techniques into the computer science mainstream and made it an influential model for subsequent research and commercial networks. ARPA followed the ARPANET with experimental packet radio and satellite networks; the need to connect these diverse systems led ARPA to begin its Internet Program, which developed techniques for interconnecting networks. These techniques were used to connect other research networks to the ARPANET, forming the basis for today's Internet, a worldwide "network of networks."

The ARPANET and Internet were socially constructed artifacts whose design was shaped by the interests and worldviews of their creators. Different networking techniques had different implications for the performance, economics, and social dynamics of the resulting system, so that technical choices can be understood as trade-offs between competing values. Analysis of the ARPANET design decisions reveals how the network was shaped by social considerations such as a preference for decentralized organization and a concern for military "survivability." Network users were also instrumental in constructing the ARPANET's identity: their unexpected enthusiasm for electronic mail turned a system intended primarily for remote computing into a medium for communication between people. The social values embodied in the ARPANET and Internet are further illuminated by contrast with alternative networking systems representing different social aims and interests that were introduced in the 1970s by international standards organizations.