Patent attributes
The present invention is concerned with situations in which call signalling follows an indirect path between an originating party and a destination party. Such an indirect path can occur when multi-homed communications networks are used. For example, where a service is provided to an enterprise which has a private address domain and that service is hosted by a service provider whose equipment is located in a public address domain connected to the enterprise domain by two or more address translators. Previously, in this type of situation, resulting media paths also follow the indirect path of the call signalling. This is wasteful of network resources. The present invention enables a direct media path to be set-up. This is achieved by enabling network address translators between two address domains to retain information in call set-up messages about the relevant address in the previous address domain and also by adding network identifier information to call set up messages.
