Embodiments disclosed herein include systems, methods, and software that reduce processing burdens on host soft switches. A method of operating a communication network comprises receiving a plurality of update messages from a plurality of border controllers that interface communications between a first packet network and a second packet network. The update messages are processed to determine operational states of the plurality of border controllers. Responsive to receiving a query from a soft switch in the first packet network for a session between the first and second packet networks, the query is processed to select a first border controller for the session from the plurality of border controllers based on the operational states of the plurality of border controllers. A response is transferred to the soft switch indicating the first border controller.