A telecommunication system that can integrate the capabilities of broadband components with the capabilities of conventional circuit switches. A signalling processor (140) receives and processes a first telecommunications signalling message (160) for the call to provide control and signalling messages (162, 163, 164, 165, 166) that identify the selection and transfer the control messages to the ATM internetworking multiplexers (110, 112, 114) that accepted the access connection for the call. The multiplexers (110, 112, 114) convert user information from the access connection into ATM cells for transmission over the virtual connection in accord with the control messages (162-166). An ATM cross connect system (120) operationally connected to the multiplexers (110, 112, 114) routes the ATM cells based on the virtual connection identified in the ATM cells. The narrowband switches (130, 132) provides the service to call based on the telecommunication signaling message.