A control apparatus includes a first apparatus for ascertaining at least one primary data path between a first and a second data terminal device, which are connected to a data network, a second apparatus for selecting one of the ascertained primary data paths and a third apparatus for ascertaining at least one alternative data path between the first and the second data terminal device, which alternative data path has no common transmission links with the selected primary data path. A corresponding network node and a corresponding method for operating the apparatus are also described.
