Implementation of a SIP Extension to Enable a More Efficient Communication Control

Nowadays, users are reachable through a number of telecommunication devices, network operators, as well as services and applications. The calling users if provided with the appropriate information can manually select the most suitable way of communication. Although this capability already affects existing business models, the lack of a transparent and a dynamic solution renders it hard to use. To tackle this issue we suggest minor extensions in the SIP protocol as well as the use of middleware to allow calling users to dynamically select the best way to route their invitation requests for multimedia communication towards called users. These extensions, based on the well established SIP standards, are described in detail while details for the incorporation of these extensions in an open source SIP protocol stack and examples are also provided.