Nowadays, many applications use multicast transmissions, such as online games, videoconference programs, or sharing applications in a P2P network. However, multicast transmission is a problem that has still not been satisfactorily solved. In this work we show a family of algorithms capable to solve this problem, concretely focused on the real-time transmissions, in which a node called root or source sends information to a specific group of nodes. These algorithms take advantage of the transmission delay of a message between one node and another in order to send it towards another node. In order to study the behaviour of these new real-time transmission algorithms we have worked with two virtual networks that models the IP network, to which we have added a number of users, from 10 to 1000. These users form the multicast group. Later, we have obtained the overlay network. This network is defined in the application layer, and the user nodes form it. Finally, the multicast algorithms have been applied on those networks and results have been analysed to extract the conclusions for our original purposes.