Abstract: An alerting system control server in a set of servers and a method therein, for alerting a user of an incoming signal for a service associated with the user. The method comprises: receiving information that an internet service server is receiving an incoming signal for the service; generating a control signal for triggering an alerting system controller to alert the user of the incoming signal for the service by activating an alerting device; identifying the alerting system controller and extracting the address of the alerting system controller; and sending the generated control signal to the identified alerting system controller, for activating the alerting device and thereby alerting the user. Also, an alerting system controller and a method therein is presented.