Kahn 和 Cerf 開始研究一套通用的通訊協定， 使得各區域的網路與網路之間，能夠溝通。 In 1973, 30 institutions are connected to the ARPANET. The network users range from industrial installations and consulting firms like BBN, Xerox PARC and the MITRE Corporation, to government sites like NASA's Ames Research Laboratories, the National Bureau of Standards, and Air Force research facilities. Bob Kahn moves from BBN to DARPA to work for Larry Roberts, and his first self-assigned task is the interconnection of the ARPANET with other networks. He enlists Vint Cerf, who has been teaching at Stanford. The problem is that ARPANET, radio-based PRnet, and SATNET all have different interfaces, packet sizes, labeling, conventions and transmission rates. Linking them together is very difficult.
例如 1982 以後， 整個 ARPAnet 改以第四版的 TCP/IP (IPv4) 為通訊協定。 1983，柏克萊將其發展的整套 UNIX 公佈於世，不收版權費； 稱為 4.2BSD (Berkeley System Distribution)。 今天所依循的 TCP/IP 標準是 1981 年確定的第四版標準 (IPv4)。 他們認為大學裡的智慧成果經該屬於全體人民。 TCP/IP 之所以成功的一大原因即 4.2BSD 包含此協定和一些基本的應用軟體。 TCP/IP 成為主流的另一個因素是美國學術網路選用此協定。 1980 後期，美國 NSF (National Science Foundation，像我們的國科會) 在北美各地設立了五個高速電腦中心 (台灣有一個，在新竹科學園區內)。 為了加強使用效率，建造了 NSFNET 連絡各中心並連到許多研究重鎮。 (相對的，台灣有 TANET，Taiwan Academic Network，台灣學術網路。) 此 NSF 網路成為今天網際網路的主幹 (backbone)。 間接的，鼓勵了各大學的校園網路也使用 TCP/IP 為通訊協定。 IPv4 與 IPv6 之爭
1984, The newly developed DNS is introduced across the Internet, with the now familiar domains of .gov, .mil, .edu, .org, .net, and .com Most important for the Internet, NSF issues a request for proposals to establish supercomputer centers that will provide access to the entire U.S. research community, regardless of discipline and location. A new division of Advanced Scientific Computing is created with a budget of $200 million over five years.
課外讀物：
[1] CIE (Connected: An Internet Encyclopedia)，由 Brent Baccala 編輯：
http://www.freesoft.org/CIE/index.htm