Patent ID: 7801134
Filing Date: 2010-09-21
Classification: H04L,H04M

Abstract:
1. A Voice over Internet Protocol (VoIP) system in which voice communication is performed between a source client for transmitting Internet Protocol (IP) packets and a destination client for receiving the IP packets via an IP network, comprising: a VoIP server connected to the IP network; and a plurality of clients including the source client and the destination client, and being connected communicably to the VoIP server via the IP network, wherein each of the clients comprises a first multicast transmission unit configured to transmit predetermined transmission data, as multicast packets addressed at a specific multicast address, to destination clients via the IP network, and a multicast transmission request unit configured to send a predetermined request message to the VoIP server so as to request the VoIP server to transmit the multicast packets, and the VoIP server comprises a second multicast transmission unit configured to transmit the multicast packets to the destination clients, upon receipt of the request message sent from the clients by the multicast transmission request unit.