A History of ARPAnet

ARPANET. The ARPANET, which is a major component of the NSFnet [National Science Foundation Network], began in 1969 as an R&D project managed by DARPA [Dept. of Defense Advanced Research Projects Agency]. ARPANET was an experiment in resource sharing, and provided survivable (multiply connected), high bandwidth (56 Kilobits per second) communications links between major existing computational resources and computer users in academic, industrial, and government research laboratories. ARPANET is managed and funded by by the DCA [Defense Communications Agency] with user services provided by a network information center at SRI International.

ARPANET served as a test for the development of advanced network protocols including the TCP-IP protocol suite introduced in 1981. TCP-IP and particularly IP, the internet protocol, introduced the idea of inter- networking -- allowing networks of different technologies and connection protocols to be linked together while providing a unified internetwork addressing scheme and a common set of transport of application protocols. This development allowed networks of computers and workstations to be connected to the ARPANET, rather than just single-host computers. TCP-IP remain the most available and advanced, non-vendor-specific, networking protocols and have strongly influenced the current international standards of activity. TCP-IP provide a variety of application services, including remote logon (Telnet), file transfer (FTP), and electronic mail (SMTP and RFC822).

ARPANET technology was so successful that in 1982, the Dept. of Defense (DOD) abandoned their AUTODIN II network project and adopted ARPANET technology for the Dept. of Defense Data Network (DDN). The current MILNET, which was split form the original ARPANET in 1983, is the operational, unclassified network component of the DDN, while ARPANET remains an advanced network R&D tested for DARPA. In practice, ARPANET has also been an operational network supporting DOD, DOE [Dept. of Energy], and some NSF-sponsored computer science researchers. This community has come to depend on the availability of the network. Until the advent of NSFnet, access to ARPANET was restricted to this community.

As an operational network in the scientific and engineering research community, and with the increasing availability of affordable super- minicomputers, ARPANET was used less as a tool for sharing remote computational resources than it was for sharing information. The major lesson from the ARPANET experience is that information sharing is a key benefit of computer networking. Indeed it may be argued that many major advances in computer systems and artificial intelligence are the direct result of the enhanced collaboration made possible by ARPANET.

However, ARPANET also had the negative effect of creating a have--have not situation in experimental computer research. Scientists and engineers carrying out such research at institutions other than the twenty or so ARPANET sites were at a clear disadvantage in accessing pertinent technical information and in attracting faculty and students.

In October 1985, NSF and DARPA, with DOD support, signed a memorandum of agreement to expand the ARPANET to allow NSF supercomputer users to use ARPANET to access the NSF supercomputer centers and to communicate with each other. The immediate effect of this agreement was to allow all NSF supercomputer users on campuses with an existing ARPANET connection to use ARPANET. In addition, the NSF supercomputer resource centers at the University of Illinois and Cornell University are connected to ARPANET. In general, the existing ARPANET connections are in departments of computer science or electrical engineering and are not readily accessible by other researchers. However, DARPA has requested that the campus ARPANET coordinators facilitate access by relevant NSF researchers.

As part of the NSFnet initiative, a number of universities have requested connection to ARPANET. Each of these campuses has undertaken to establish a campus network gateway accessible to all due course, be able to use the ARPANET to access the NSF supercomputer centers, from within their own local computing environment. Additional requests for connection to the ARPANET are being considered by NSF.