The present invention provides a method for sending a message to a network device with a specific MAC address, in an IP network implementing a internet group management protocol IGMP, comprising: sending, by a network terminal, to the network device, a multicast group management status message including a destination address set as the specific MAC address A system comprises a multitude of end-user devices coupled via a broadband connection with a service provider network, a publish/subscribe broker adapted to communicate with the multitude of end-user devices and at least a first back-end entity coupled with the service provider network. The first back-end entity includes a first client software application for connecting to the publish/subscribe broker and publishes control data via a control data channel for a device management of the end-user devices. The end-user devices include a second client software application for connecting to the publish/subscribe broker for subscribing to the control data channel and for receiving the control data, and for publishing device data and action data as instructed by the control data. The backend entity authorization is validated in particular by using a control data signature.