The ARPANET is an operational, resource sharing inter-computer network linking a wide variety of computers at Defense Advanced Research Projects Agency (DARPA) sponsored research centers and other DoD and non-DoD activities in CONUS, Hawaii, Norway, and England. The ARPANET originated as a purely experimental network in late 1969 under a research and development program sponsored by DARPA to advance the state-of-the-art in computer internetting. The network was designed to provide efficient communications between heterogeneous computers so that hardware, software, and data resources could be conveniently and economically shared by a wide community of users. As the network successfully attained its initial design goals, additional users were authorized access to the network. Today, the ARPANET provides support for a large number of DoD projects and other non-DoD govern- ment projects with an operational network of many nodes and host computers.