A system (111) and method for notifying subscriber devices (121) communicated with a subscriber local area network (120) and an ISP network operator (100) for receiving (101) notification requests comprises: a contact database (14) of subscriber devices (121) and notification mechanisms available for each subscriber device (121), a query manager (11) which consults the contact database (14) to verify the subscriber device (121) and its available notification mechanisms and sends a state of the notification request to the ISP network operator (100), a detector (13) for inventorying each subscriber device (121) in the contact database (14), analyzing (105) traffic from the subscriber local area network (120) and identifying notification mechanisms of each inventored subscriber device (121); a notifier (12) which selects (108) at least one notification mechanism from the available notification mechanisms for notifying the destination subscriber device (121) using the selected notification mechanism if any available.