A system for transmitting data through an IP core network so that data may be transmitted from an originating source, through a public switched telephone network (PSTN) and through the IP core network to a land line telephone and a cellular telephone. The system includes an IP core network that is coupled to the PSTN through an interface. The IP core network is also coupled to an access IP network. A radio access network is coupled to the IP core network and the cellular telephone. Upon receipt of data from the originating source, the IP core network simultaneously initiates a ringing of the land line telephone through the access IP network and a paging of the cellular telephone through the radio access network.