The calling extension number is translated into a specific GSM dedicated number in the virtual network, and a 2M digital trunk is selected to call the mobile gateway office GMSC. The GMSC then sends the calling and called information of the call to the service switching of the intelligent network platform. Point SSP, the SSP to trigger the service control point SCP, so that the convergence of wired and wireless. Not only is it convenient for users, it also realizes that the PBX switch extension dials the group mobile virtual network number like a mobile phone and binds the group customer's mobile phone with the internal switch, which not only stabilizes the group's large customers, but also develops the mobile phone users, and also maximizes the savings. The company's communication costs and mobile phone user's calls, and for the mobile company to create economic and social benefits, but also for the integration of 2M broadband data services and other value-added services to lay the foundation.