Abstract: A system for sending a data packet from a first communication network (255) to a second communication network (270) is disclosed in which the second communication network (270) is directly unreachable by the first communication network (255). The system comprises a transmitting device for transmitting the data packet to the first communication network; a receiving device for accepting the data packet from the second communication network and generating a data packet response; and a relay (260) for acceptance of the data packet from the first communication network (255), passing the data package to the second communication network (270) and for acceptance of the generated data package response and passing the generated data packet response to the first communication network (255).