A method for communication in an environment including a circuit-switched network and a packet-switched network, both of which include a respective connectivity layer including one or more switching elements and a respective service layer including one or more service platforms. A request is accepted to set up a call for a communication terminal associated with one or more of the networks. The call is established responsively to the request via one or more of the switching elements. At least one service platform in the service layer of the circuit-switched network is invoked to provide a first ancillary call service to the call, and at least one second service platform in the service layer of the packet-switched network is invoked to provide a second ancillary call service to the call.