The Defense Switched Network (DSN) is a primary information transfer network

Telecommunications network

A telecommunications network is a collection of terminals, links and nodes which connect together to enable telecommunication between users of the terminals. Networks may use circuit switching or message switching. Each terminal in the network must have a unique address so messages or connections...

 for the Defense Information Systems Network

Defense Information Systems Network

The Defense Information System Network has been the United States Department of Defense's enterprise network for providing data, video and voice services for 40 years....

 (DISN). The DSN provides the worldwide non-secure voice, secure voice

Secure voice

Secure voice is a term in cryptography for the encryption of voice communication over a range of communication types such as radio, telephone or IP.-History:...

, data, facsimile

Fax

Fax , sometimes called telecopying, is the telephonic transmission of scanned printed material , normally to a telephone number connected to a printer or other output device...

, and video teleconferencing services for DOD

United States Department of Defense

The United States Department of Defense is the U.S...

 Command and Control

Command and Control (military)

Command and control, or C2, in a military organization can be defined as the exercise of authority and direction by a properly designated commanding officer over assigned and attached forces in the accomplishment of the mission...

 (C2) elements, their supporting activities engaged in logistics

Logistics

Logistics is the management of the flow of goods between the point of origin and the point of destination in order to meet the requirements of customers or corporations. Logistics involves the integration of information, transportation, inventory, warehousing, material handling, and packaging, and...

, personnel, engineering

Engineering

Engineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...

, and intelligence

Intelligence (information gathering)

Intelligence assessment is the development of forecasts of behaviour or recommended courses of action to the leadership of an organization, based on a wide range of available information sources both overt and covert. Assessments are developed in response to requirements declared by the leadership...

, as well as other Federal

Federal government of the United States

The federal government of the United States is the national government of the constitutional republic of fifty states that is the United States of America. The federal government comprises three distinct branches of government: a legislative, an executive and a judiciary. These branches and...

 agencies.

In 1982, the DSN was designated by the Office of the Secretary of Defense

Office of the Secretary of Defense

The Office of the Secretary of Defense is a headquarters-level staff of the Department of Defense of the United States of America. It is the principal civilian staff element of the Secretary of Defense, and it assists the Secretary in carrying out authority, direction and control of the Department...

 (OSD) and the Joint Chiefs of Staff

Joint Chiefs of Staff

The Joint Chiefs of Staff is a body of senior uniformed leaders in the United States Department of Defense who advise the Secretary of Defense, the Homeland Security Council, the National Security Council and the President on military matters...

 (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. The network assures nonblocking service for users with "flash" and "flash override" precedence capabilities

Autovon

AUTOVON, short for Automatic Voice Network, was an American military phone system built in 1963 to survive nuclear attacks. AUTOVON was first established in the United States, using the Army's SCAN system. Around the mid-1970s AUTOVON expanded to the United Kingdom, Asia, the Middle East, and Panama...

. Key users include the National Command Authorities, Commanders of the Combatant Commands, and subordinate component commanders. DSN replaced the older Autovon

Autovon

AUTOVON, short for Automatic Voice Network, was an American military phone system built in 1963 to survive nuclear attacks. AUTOVON was first established in the United States, using the Army's SCAN system. Around the mid-1970s AUTOVON expanded to the United Kingdom, Asia, the Middle East, and Panama...

 system.

The DSN consists of four subsystems:

• Switching,
• Transmission,
• Timing and Synchronization, and
• Network Administration
  Network administrator
  A network administrator, network analyst or network engineer is a person responsible for the maintenance of computer hardware and software that comprises a computer network...
  
   and Management.

The DSN Switching Subsystem consists of multifunction, stand-alone tandem

Class 4 telephone switch

A Class 4, or Tandem, telephone switch is a U.S. telephone company central office telephone exchange used to interconnect local exchange carrier offices for long distance communications in the Public Switched Telephone Network....

, end office, and remote switching units. 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-III

STU-III

STU-III is a family of secure telephones introduced in 1987 by the NSA for use by the United States government, its contractors, and its allies. STU-III desk units look much like typical office telephones, plug into a standard telephone wall jack and can make calls to any ordinary phone user...

s), the Secure Terminal Equipment

Secure Terminal Equipment

Secure Terminal Equipment is the U.S. Government's current , encrypted telephone communications system for wired or "landline" communications. STE is designed to use ISDN telephone lines which offer higher speeds of up to 128k bits per second and are all digital...

 (STE), the dial-up alternative routing for the Unclassified but Sensitive Internet Protocol

Internet Protocol

The Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...

 (IP) Router Network (NIPRNet), and the Secret IP Router Network (SIPRNet

SIPRNet

The Secret Internet Protocol Router Network is "a system of interconnected computer networks used by the United States Department of Defense and the U.S. Department of State to transmit classified information by packet switching over the TCP/IP protocols in a 'completely secure' environment"...

). The DSN can also provide access to the Government Emergency Telephone System (GETS).

External links

• A brief history of and video about the DSN US Government Defense Information Systems Agency