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The National Communications System (NCS) Voice Precedence System, was established by NCS Memorandum 1-70, dated 14 Feb. 1970, is directed for use by all authorized users of voice communications facilities. Since the effectiveness of the system depends on the cooperation of the people authorized to use it, users must: (1) be familiar with the purposes of each precedence category and the type of call that is assigned the precedence, and (2) exercise care not to request or use a precedence higher than required.

CJCSI 6215.01C, Policy for DoD Voice Networks, defines how Precedence Levels are assigned and controlled.

The NCS Voice Precedence System does not make provisions for conducting test and exercise calls. Those activities or individuals authorized or required to conduct such tests or exercise calls will use a precedence consistent with the nature of the test or exercise. When the originator of the test or exercise call has contacted the called party, the call will be identified immediately as a flash, immediate, or priority precedence test or exercise.

The following examples should aid users in determining what precedence to use when placing a call. These examples are according to the NCS Voice Precedence System, but are not to be used exclusively for determination of the precedence of a call. This should be at the discretion of the originator of the call.


Flash override is considered a capability, not a level of precedence. Exercising this capability preempts calls of all other levels or precedence. The flash override capability is available to the following users:

  • The President of the United States of America
  • The Secretary of Defense and the Chairman of the JCS
  • Commanders of the Unified Commands


Flash calls preempt immediate, priority, and routine calls. Listed below are examples of flash calls:

  • Calls pertaining to C2 of military forces essential to defense and retaliation
  • Critical intelligence essential to national survival
  • Conduct of diplomatic negotiations critical to ceasing or limiting hostilities
  • Dissemination of critical civil alert information essential to national survival
  • Continuity of federal government functions essential to national survival
  • Fulfillment of critical United States internal security functions essential to national survival
  • Catastrophic events of national or international significance


Immediate calls preempt priority and routine calls and are reserved for communications pertaining to situations that gravely affect the security of national and Allied forces. Listed below are some examples of immediate calls:

  • Reconstitution of forces in a post-attack period
  • Intelligence essential to national security
  • Conduct of diplomatic negotiations to reduce or limit threat of war
  • Implementation of federal government actions essential to national survival
  • Situations that gravely affect the security of the United States
  • Civil defense actions concerning the direction of the population and their survival
  • Disaster or events serious enough to have an immediate and detrimental effect on the welfare of the population
  • Vital information having an immediate effect on aircraft, spacecraft, or missile operations
  • Distress assistance


Priority calls preempt routine calls and are reserved for communications requiring expeditious action by called parties furnishing essential information for conducting government operations.


The routine precedence applies to official government communications that require rapid transmission by telephonic means, but do not require preferential handling. A routine call does not preempt any other call.


Access to a level of precedence must be determined only by mission requirements and must not be used as a means of improving a GOS above that provided to ROUTINE users. Appropriate restoration priority or TSP should be considered with all special C2 precedence requirements. Any change in the assignment of precedence levels must be reviewed by DISA to ascertain the network impact and to size the DSN architecture to accommodate the change. All precedence requirements must be validated by the appropriate CINC, Service Chief, or director of Defense agency, who also approves requirements for immediate and priority service. Requests for precedence are not restricted by MCA. The Joint Staff is the approval authority for flash and flash override calling capabilities. With the exception of new missions, requests for flash and flash override should normally be accompanied by a tradeoff of equal precedence.


The CINCs, Service Chiefs and directors of Defense agencies must establish and maintain policy to control use of precedence access through operator-assisted calls. EO switch users/subscribers are authorized precedence and long-distance DSN service only when a means is provided to positively control the number of simultaneous outgoing calls for each precedence level entering the DSN e.g., instrument classmarks. DISA provides criteria for the EO switch processing of precedence calls to and from DSN to achieve the stated GOS and will determine the appropriate trunk sizing and switch configuration based on CINC, Service, or agency requirements and traffic-engineering analysis. Traffic-engineering and trunk-sizing requirements are based on business hours between DSN locations.


Local commanders are responsible for both the control and approval of the calling area capabilities available to their DSN users.


When NM capabilities, per paragraph 9, are available, classmarking of the user lines is employed to technically activate, manage, and control calling capabilities. When NM capabilities are not available, PATs or classmarking of access lines are employed to control access to the DSN.


Temporary DSN service upgrading to support the NCA, Chairman of the Joint Chiefs of Staff, CINCs, Service Chiefs, or other equivalent personnel during travel is authorized for all precedence levels for up to 30 days. Temporary upgrading is also authorized for emergencies and exercises. Requests should follow the procedures in Enclosure C and must be coordinated with DISA and approved by the CINC or the Service Chief concerned. Approvals of flash override and flash access must be provided to DISA and the Joint Staff. The CINC or Service Chief must identify source of funding to cover additional costs prior to approval.


The CINCs, Service Chiefs, and directors of Defense agencies must develop implementing policies and procedures for the provisions of this policy. The policies and procedures must be coordinated with and provided to DISA to ensure that they do not adversely affect network operation.