A method for identifying undesirable calls to a call-enabled terminal of a subscriber in a communication network, comprising the following steps: • receiving call information data that characterizes the activated call, by means of an identification server of the communication network, wherein an algorithm for identifying undesirable calls is implemented on the identification server, wherein the algorithm is programmed to perform at least one of the following identification methods: ∘ a call pattern analysis, wherein the call pattern analysis is configured to compare a typical call pattern known from the terminal with the call information data and to identify an undesirable call from the comparison; ∘ a voice analysis, wherein the voice analysis is configured to extract speech as audio signals from the call information data and compare them with the known speech profiles and to identify an undesirable call from the comparison; ∘ context analysis, wherein the context analysis is configured: to extract speech as audio signals from the call information data in a first step; to convert the speech into text in a second step; and, in a third step, to analyse the text in a context-dependent manner to identify an undesirable call, characterized in that the following combinations are implemented: i) the call pattern analysis and the voice analysis; or ii) the call pattern analysis and the context analysis, or iii) the voice analysis and the context analysis, or iv) the call pattern analysis and the voice analysis and the context analysis, wherein the algorithm detects an undesirable call if a defined probability threshold has been exceeded, wherein each of the analysis methods and the implemented combinations have their own specified probability values. • receiving call information data that characterizes the activated call, by means of an identification server of the communication network, wherein an algorithm for identifying undesirable calls is implemented on the identification server, wherein the algorithm is programmed to perform at least one of the following identification methods: ∘ a call pattern analysis, wherein the call pattern analysis is configured to compare a typical call pattern known from the terminal with the call information data and to identify an undesirable call from the comparison; ∘ a voice analysis, wherein the voice analysis is configured to extract speech as audio signals from the call information data and compare them with the known speech profiles and to identify an undesirable call from the comparison; ∘ context analysis, wherein the context analysis is configured: to extract speech as audio signals from the call information data in a first step; to convert the speech into text in a second step; and, in a third step, to analyse the text in a context-dependent manner to identify an undesirable call, characterized in that the following combinations are implemented: i) the call pattern analysis and the voice analysis; or ii) the call pattern analysis and the context analysis, or iii) the voice analysis and the context analysis, or iv) the call pattern analysis and the voice analysis and the context analysis, wherein the algorithm detects an undesirable call if a defined probability threshold has been exceeded, wherein each of the analysis methods and the implemented combinations have their own specified probability values. ∘ a call pattern analysis, wherein the call pattern analysis is configured to compare a typical call pattern known from the terminal with the call information data and to identify an undesirable call from the comparison; ∘ a voice analysis, wherein the voice analysis is configured to extract speech as audio signals from the call information data and compare them with the known speech profiles and to identify an undesirable call from the comparison; ∘ context analysis, wherein the context analysis is configured: to extract speech as audio signals from the call information data in a first step; to convert the speech into text in a second step; and, in a third step, to analyse the text in a context-dependent manner to identify an undesirable call,