System Interconnections | U.S. Classified National Security System Connections, v1.0

Defines conformance and assessment criteria for verifying that an organization prohibits the direct connection of a U.S. classified, national security system to an external network without the use of organization-defined boundary protection device.
If an assessment step references organization-defined elements (E.g. <organization-defined personnel or roles>, <organization-defined frequency>, etc.), corresponding citations/excerpts must be provided to confirm that the organization has established and documented these values and that they apply as referenced in the conformance criteria.

Similarly, if a "Selection" among multiple options (e.g. [Selection (one or more): as needed; ]) is specified, evidence must be provided to establish that the option(s) implemented by the organization have been defined and documented.

The assessment step shall not be marked as satisfied without this evidence.

Assessment Step

1
System Interconnections | U.S. Classified National Security System Connections (SystemInterconnectionsUSClassifiedNationalSecuritySystemConnections)
Does the organization prohibit the direct connection of a U.S. classified, national security system to an external network without the use of [Assignment: organization-defined boundary protection device]?
Artifact
A1
Provide evidence (e.g. organizational policies, procedures, compliance/assessment reports, etc.) that support the assessor's response to this assessment step.
If conformance criteria reference organization-defined elements (e.g. <organization-defined personnel or roles>, <organization-defined frequency>, etc.), these values must be defined and documented by the organization.

Similarly, if the criteria specify a "Selection" among multiple options (e.g. [Selection (one or more): as needed; ]), the option(s) implemented by the organization must also be defined and documented.

Conformance Criteria (1)

C1
The organization prohibits the direct connection of a classified, national security system to an external network without the use of [Assignment: organization-defined boundary protection device].
Citation
SP800-53R4
Appendix F, CA-3 (2)