Nationwide networking method for IVPNs (integrated virtual private networks) of large-and-medium-sized enterprises

The invention discloses the field of digital communication, and in particular relates to a nationwide networking method for IVPNs of large and medium-sized enterprises, and the method adopts a direct mapping and network topological structure of cross-regional communication links in the country. The method comprises the steps as follows: 1), basic management data of group modes of mobile telephones and fixed-line telephones in an enterprise network are constructed; 2), users of other networks access IPPBX (Internet protocol private branch exchange), the fixed-line telephones access the IPPBX through original AG resources or IADs (integrated access devices); 3), the IPPBX accesses the CMNET (China Mobile Net) through E1, bridging is realized through the E1, and the E1 which is connected with a PBX (private branch exchange) originally is connected to the IPPBX; 4), the IPPBX is taken as SIPGW in a preliminary period, and the PBX is replaced in a later period, and all users are switched to the IPPBX; and 5), the topological structure is constructed, corresponding encoding and decoding data bases of the E1 are constructed, and specific data and decoding rules are led to communication switching equipment of communication operators. The method has the advantages that the cost is reduced, the communication is convenient and fast, even number call and free choice are realized, and the like.