Method for reporting error in mobile telecommunications network and mobile telecommunications network thereof

A method of reporting errors in a mobile telecommunications network comprising a core network and a UMTS Terrestrial Radio Access Network (UTRAN). The method comprises the steps of generating an error message at an error originating entity in either the core network or the UTRAN, sending the error message to an error destination entity in the other of the core network and the UTRAN over an Iu interface, and incrementing a distance counter contained in or accompanying the error message at each intermediate entity through which the error message passes. The error destination entity is able to identify the error originating entity on the basis of the value of the distance counter contained in or accompanying the received error message.