SC-7 - Boundary Protection

a. Monitor and control communications at the external managed interfaces to the system and at key internal managed interfaces within the system; b. Implement subnetworks for publicly accessible system components that are [Selection: physically; logically] separated from internal organizational networks; and c. Connect to external networks or systems only through managed interfaces consisting of boundary protection devices arranged in accordance with an organizational security and privacy architecture.


Space Segment Guidance

Boundary protection for spacecraft spans RF front ends, ground-station demarcations, TT&C enclaves, and payload↔bus gateways. Consider tightly managed interfaces for all external connections; protocol and command whitelists; content/format validation for cross-domain transfers (e.g., planning data → command stacks); and one-way or brokered patterns where appropriate. Validate enforcement in a twin/flatsat with malformed CCSDS frames, jittered timing, and handover scenarios, and surface clear accept/reject reason codes in telemetry.