FIELD: data networks.
SUBSTANCE: invention relates to the field of services provided in data networks based on unidirectional selective call sessions, including direct talk (PTT), under the control of a PT server within the framework of a service based on SIP (Session Initiation Protocol). To achieve the effect, when establishing a group packet voice communication session over data transmission networks, the first user terminal sends a request to establish a group packet voice communication session to the multicast server via a signaling channel to initiate a connection between the server and the user terminal; the multicast server receives a request to establish a multicast session of packet voice communication from the first user terminal and creating a network route between the multicast server and user terminals, including at least transmitting a server connection request to the user terminals of the group, and transmission by the user terminal of voice packets to the multicast server, the created network route between the multicast server and the user terminals is maintained in an active state by sending repeated registration packets or keep-alive packets, the transmission of voice packets to the multicast server is also performed via signaling channels using the user datagram. Each voice packet is a request to establish a group packet voice session and contains information necessary to initiate a connection between the server and the user terminal.
EFFECT: reduction of the time to establish a multicast service due to the fact that a communication session begins without a preliminary exchange of signaling messages, and immediately upon receipt of the first voice packet.
2 cl, 2 dwg
