1. A method of operating a communication system comprising a routing system and a call processing system that is configured to communicate with more than one call manager systems, the method comprising: in the routing system, receiving signaling for a call wherein the signaling indicates a called number including an international country code; processing the international country code to transfer a first query including the international country code from the routing system to the call processing system; in the call processing system, processing the international country code to select one of the call manager systems from the more than one call manager systems, wherein the more than one call manager systems are located at more than one call centers respectively; transferring a second query to the one call manager system; receiving a response from the one call manager system; and processing the response to transfer a routing instruction for the call.