Abstract: In a communication network where a subscriber is connected to switches in an originating carrier communications are routed to and/or from the subscriber via at least one communications carrier selected from a plurality of possible communications carriers. Communications control signals associated with outgoing and/or incoming communications are received from the switch at a controller external to the originating carrier. The communications control signals are processed at the controller in dependence upon directions from a third party using information on communications costs for each of the possible communications carriers to select at least one communications carrier for routing communications based on the information on communications cost to generate process communications control signals for routing the communications in accordance with the selection.