A method for detecting network failures, based on data from RADIUS server within the range of PPP sessions, comprising following steps: - receiving and recording data from RADIUS server logs, then - performing an analysis of the recorded data at least once, - then detecting disconnections of PPP sessions passing through a specific network resource within a time window, then - waiting for a further time window to end and - performing verification of the disconnections of PPP sessions; - when verification of the disconnection of PPP sessions is negative, the method for detecting network failures is ended, - and when verification of the disconnection of PPP sessions is positive, an alarm is generated to a maintenance system and/or users are notified; then - performing verification whether a maximum waiting time for the return of PPP sessions was exceeded, where the maximum waiting time is a defined parameter, and - performing verification of a result of comparison between the number of re-established PPP sessions and a threshold value, where the threshold value is another defined parameter; - when verification whether the maximum waiting time for the return of PPP sessions was exceeded is negative, and when the number of re-established PPP sessions is equal to or greater than the threshold value, the users are notified and/or the alarm is turned off; - and when verification whether the maximum waiting time for the return of PPP sessions was exceeded is negative, and when the number of re-established PPP sessions is less than the threshold value, the method returning to the step of verification whether the maximum waiting time for the return of PPP sessions was exceeded; - after exceeding the maximum waiting time for the return of PPP sessions, the verification of the number of re-established PPP sessions is ended, wherein the step of verification of the disconnection of PPP sessions includes at least one step of the following: - performing verification of a first minimum number of re-established PPP sessions; - performing verification of a ratio of the number of disconnected PPP sessions to previously active PPP sessions on a specific resource; - performing retrieval of data from the specific network resource and performing confirmation of a failure occurrence on the basis of the retrieved data from the specific network resource; and - performing verification of disconnections of PPP sessions on a device higher in a network hierarchy. - receiving and recording data from RADIUS server logs, then - performing an analysis of the recorded data at least once, - then detecting disconnections of PPP sessions passing through a specific network resource within a time window, then - waiting for a further time window to end and - performing verification of the disconnections of PPP sessions; - when verification of the disconnection of PPP sessions is negative, the method for detecting network failures is ended, - and when verification of the disconnection of PPP sessions is positive, an alarm is generated to a maintenance system and/or users are notified; then - performing verification whether a maximum waiting time for the return of PPP sessions was exceeded, where the maximum waiting time is a defined parameter, and - performing verification of a result of comparison between the number of re-established PPP sessions and a threshold value, where the threshold value is another defined parameter; - when verification whether the maximum waiting time for the return of PPP sessions was exceeded is negative, and when the number of re-established PPP sessions is equal to or greater than the threshold value, the users are notified and/or the alarm is turned off; - and when verification whether the maximum waiting time for the return of PPP sessions was exceeded is negative, and when the number of re-established PPP sessions is less than the threshold value, the method returning to the step of verification whether the maximum waiting time for the return of PPP sessions was exceeded; - after exceeding the maximum waiting time for the return of PPP sessions, the verification of the number of re-established PPP sessions is ended, wherein the step of verification of the disconnection of PPP sessions includes at least one step of the following: - performing verification of a first minimum number of re-established PPP sessions; - performing verification of a ratio of the number of disconnected PPP sessions to previously active PPP sessions on a specific resource; - performing retrieval of data from the specific network resource and performing confirmation of a failure occurrence on the basis of the retrieved data from the specific network resource; and - performing verification of disconnections of PPP sessions on a device higher in a network hierarchy. - performing verification of a first minimum number of re-established PPP sessions; - performing verification of a ratio of the number of disconnected PPP sessions to previously active PPP sessions on a specific resource; - performing retrieval of data from the specific network resource and performing confirmation of a failure occurrence on the basis of the retrieved data from the specific network resource; and - performing verification of disconnections of PPP sessions on a device higher in a network hierarchy.