Abstract: The invention is a system for interfacing an ISDN or non-ISDN system with a broadband system. The broadband system can be an ATM system. The invention can process the ISDN signaling to select ATM connections and then interwork the ISDN connections with the selected ATM connections. The invention can interwork ISDN signaling and SS7 signaling. The invention can also process SS7 signaling to select ISDN connections and then interwork ATM connections with the selected ISDN connections. The invention can also interwork ISDN systems with non-ISDN systems.