Which communication links count as critical in the protection needs assessment?

Links into public networks, links carrying highly sensitive information, and links over which confidential information must NOT travel.

* The three kritische Verbindungen — to public networks, carrying highly sensitive data, and those that must NOT carry confidential data. *

Three categories of kritische Verbindungen (marked red in the network plan):

1. Connections to public networks or across public ground — Internet, telephone network, lines crossing public property (exposed to outsiders)
2. Connections transporting especially sensitive information — they inherit a high protection need from the data
3. Connections over which confidential information may NOT be transmitted — these need attention to enforce the restriction (e.g. a guest WLAN that must never see internal data)

The protection need of the transmitted information derives from the protection need of the connected IT systems.

Tip: The third category surprises people: a link can be critical because of what must be kept off it, not what flows over it.