A system and method for determining inter-carrier network usage may be used. The method may include determining network usage of a first packet network managed by a first communications carrier by subscribers of a second communications carrier that manages a second packet network. The network usage may distinguish communications of data packets including real-time content and non-real-time content. Network usage of the second packet network by subscribers of the first communications subscriber may be determined. A network usage differential between the determined usages of the first and second packet networks may be determined, where the network usage information may distinguish communications of data packets including real-time and non-real-time content.