Considers the threats and requirements specific to PBX systems and the corresponding parts of hybrid systems, to protect the information transmitted via the PBX and to protect the system itself against external interference and manipulation. In Edition 2023 the Baustein carries 19 requirement numbers, 17 of them live: 3 Basis requirements (B, MUSS, to be fulfilled first and without exception), 12 Standard requirements (S, SOLLTE) and 2 requirements for elevated protection needs (H), with 2 numbers withdrawn (ENTFALLEN) and kept for stable numbering. It is applied to an IT system in modelling order R2. The requirements property on this node lists every requirement by number, title, level and responsible role, so a requirement is cited as NET.4.1.A<n>.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.