Internetworking research in the early 1970s by Bob Kahn at DARPA and Vint Cerf at Stanford University and later DARPA led to the formulation of the Transmission Control Program, which incorporated concepts from the French CYCLADES project directed by Louis Pouzin. As this work progressed, a protocol was developed by which multiple separate networks could be joined into a network of networks. Version 4 of TCP/IP was installed in the ARPANET for production use in January 1983 after the Department of Defense made it standard for all military computer networking.