STANAG 5639 protected core networking (PCN) static environment specifications

What it is

STANAG 5639 is a NATO Standardization Agreement, currently Edition 1, dated 5 December 2025. It is not a technical specification. It is the agreement by which NATO nations commit to ratify and implement AComP-5639, Edition A, the Allied Communications Publication that sets out the protected core networking (PCN) static environment specifications. The specifications themselves, the detail a reader usually wants, live inside AComP-5639, not inside this cover. Read on its own, STANAG 5639 requires almost nothing of a supplier directly. Its obligations run to nations, and it reaches a contractor only indirectly, once a nation has implemented it and a contract or task order names AComP-5639's requirements.

Who it binds, and how

STANAG 5639 is explicit that it binds nations rather than organisations. It "is effective upon receipt for use by the participating nations and NATO bodies." Its letter of promulgation describes the enclosed agreement as one "which has been ratified by member nations, as reflected in the NATO Standardization Documents Database (NSDD), is promulgated herewith." Ratification and implementation are separate steps: nations that have not already done so are invited to "advise the NSO of their intention regarding its ratification and implementation." So "is STANAG 5639 mandatory" has no single answer. It depends on whether a given nation has ratified and implemented it, and, for a supplier, on whether a specific contract invokes AComP-5639 as a result.

What the agreement actually commits nations to

The stated aim is to respond to a set of interoperability requirements: PCN "provides the specifications required interconnect efficiently different national network segments so as to formulate a global, core network while at the same time ensuring a minimum level of security and quality services." The document adds that the PCN Core specifications cover "both Static and Deployable environments, as well as the description of interoperable capabilities between them." Under "Agreement," participating nations agree to implement AComP-5639, Edition A. None of this is written as a duty on a supplier; it is a duty on the nation, and on the network segments and commands that build and connect to the protected core.

A cover agreement, not the network specification itself

A reader who only has STANAG 5639 in hand does not yet have the static-environment specifications themselves. AComP-5639 holds the technical detail this STANAG points at. This document names two sibling publications for context: STANAG 5637 (AComP-5637, the Protected Core Networking specifications in general) and STANAG 5640 (AComP-5640, the deployable-environment counterpart to this static-environment document). Neither is a prerequisite in a supplier's own sense; they show where AComP-5639 sits among NATO's other PCN publications.

Implementation and review

STANAG 5639 "is implemented when a nation has issued instructions that all national documents will follow the provisions of this agreement when connecting different national network segments so as to build a federated operational backbone network." Allies and NATO bodies report implementation details through the electronic reporting tool, and partner nations are separately invited to do the same. This is Edition 1: the document states plainly, "This STANAG does not supersede any document." The STANAG "is to be reviewed in accordance with AAP-03." The result is recorded in the NSDD, and the agreement is supervised under NATO's digital policy and communications-and-information committee chain.

What it does not cover

STANAG 5639 names no supplier obligation directly: every duty in the text runs to "nations" or "NATO bodies," never to a contractor or manufacturer. It also names no assessment or certification scheme of any kind. The only stated check is that the agreement itself is reviewed periodically against AAP-03, not that an organisation, a network segment or a PCN implementation is certified.

Standards it references

• STANAG 5637Background
• AComP-5637Background
• STANAG 5640Background
• AComP-5640Background