Milnet, an acronym for Military Network, was the name of the Advanced Research Projects Agency Network (ARPANET). It only carries unclassified information and was intended for use by U.S. Department of Defense traffic. In 1983, both ARPANET and MILNET split into two networks.
Subsequently, it was decided that ARPANET would dedicate itself entirely to supporting the academic research community and that MILNET would be used to transmit U.S. military information, thereby meeting the needs of the military. And direct disconnection between the two networks due to security. These two networks were built and operated by BBN Technologies and so they used the same technology.
The new standard rules and divisions believe that the ARPANET was originally created for military purposes. The development of the Transmission Control Protocol (TCP) and the Internet Protocol (IP) and its decentralized structure helped ARPANET significantly develop into the 1980s. Milnet, on the other hand, which occupied 65 of the 113 nodes or connection points to secure military data, further expanded that it was included by the Defense Data Network (DDN). DDN is a set of global military networks used in various security levels.
In 1990, the landscape changed. The world has realized the potential of massive interconnection and this has led to the advent of the Internet. The military agencies that realized this possibility went for further expansion of MILNET. It began providing Internet Protocol (IP) connections to various US military bases at home and abroad.
It was then split into several networks, such as the Secret Internet Protocol Router Network (SIPRNET), the Non-Classified Internet Protocol Router Network (NIPRNET), and the Joint Worldwide Intelligence Communication System (JWICS). Today a part of MILNET that has become NIPRNET is used by the US military to exchange sensitive and classified data between internal users.