For CONFIDENTIAL, SECRET and TOP SECRET systems, agencies planning to send classified information over telephone systems must ensure that: (1) the system is accredited for that purpose; and (2) any classified traffic crossing external systems is suitably encrypted.
This control maps to 1 controls across 1 other frameworks. If you already hold one of them, the evidence you collected for it is the starting point here rather than new work.
Every mapping shown was judged rather than inferred from wording similarity, and the ones that failed review are published too. See the coverage reports and what was rejected.
The graph holds this control, the 1 it maps to, and the evidence behind each claim, over MCP and REST.