Abstract: Signalling messages may be monitored in a telecommunications network by receiving an indication of a signalling message for a network entity of the telecommunications network, the signalling message comprising a signalling dialog identifier. The signalling dialog identifier of the received signalling message is compared with a list of known signalling dialog identifiers relating to the network entity and the signalling message is categorized based on a result of the step of comparing, for example as suspicious. If a number of signalling messages for a network entity of the telecommunications network categorized as suspicious and having a common additional characteristic is at least a threshold value, an alert may be generated.

Abstract: Signalling messages may be monitored in a telecommunications network by receiving an indication of a signalling message for a network entity of the telecommunications network, the signalling message comprising a signalling dialogue identifier. The signalling dialogue identifier of the received signalling message is compared with a list of known signalling dialogue identifiers relating to the network entity and the signalling message is categorised based on a result of the step of comparing, for example as suspicious. If a number of signalling messages for a network entity of the telecommunications network categorised as suspicious and having a common additional characteristic is at least a threshold value, an alert may be generated.

Abstract: A Gateway Location Register (GLR) for a Public Land Mobile Network (PLMN) stores information relating to each Mobile Subscriber (MS) roaming in the PLMN. The GLR may receive a request from an associated visitor registration entity of the PLMN relating to one MS and, in response, perform an action based on the stored information relating to a plurality of MS. Additionally or alternatively, the GLR selects at least one MS currently roaming in the PLMN and performs an action for at least one selected MS. The action may comprise sending a message to a visitor registration entity of the PLMN associated with each selected MS or be performed in response to a request received from an associated visitor registration entity of the PLMN in respect of a selected MS.