The DSN provides the worldwide non-secure voice, secure voice, data, facsimile, and video teleconferencing services for DOD Command and Control (C2) elements, their supporting activities engaged in logistics, personnel, engineering, and intelligence, as well as other federal agencies.
In 1982, the DSN was designated by the Office of the Secretary of Defense (OSD) and the Joint Chiefs of Staff (JCS) as the provider of long-distance communications service for the DOD.
The DSN is designated as a primary system of communication during peacetime, periods of crisis, preattack, non-nuclear, and post-attack phases of war.
Using the transmission, timing, and control elements of the DISN, they interconnect all military locations worldwide and provide end-to-end long-distance common user and dedicated voice, secure voice, data, and video services worldwide.
In addition to nonsecure voice, data, and video services, the DSN will provide transmission, switching, and support services for Secure Telephone Units, Third Generation (STU-IIIs, now obsolete), the Secure Terminal Equipment (STE), the Defense Red Switch Network (DRSN), the dial-up alternative routing for the Unclassified but Sensitive Internet Protocol (IP) Router Network (NIPRNet), and the Secret IP Router Network (SIPRNet).