A system includes a core routing engine operable to receive a call setup request and identify one or more IP trunk groups through which the call setup request can be routed, select one of the one or more identified IP trunk groups and route the call setup request to an internal IP address associated with the selected IP trunk group. The system may further include an IP edge node associated with the internal IP address, the IP edge node in the backbone network and operable to receive the call setup request and route the call setup request to one of a plurality of IP addresses associated with a plurality of carrier edge nodes in the carrier network.