Centrex Business Security Research Under A Unified IMS

China Mobile’s innovative IMS international standards on the basis of the CM-IMS. The CM-IMS is an end-to-end client systems-level solutions, China Mobile for the entire business operations involved in the core network, access devices, terminals, operations, hosting and support systems.Unified CM-IMS-based Centrex business, flexibility and openness of the IMS architecture and business expansion for users across the network and inter-regional, inter-terminal integration of Centrex services. Users in addition to traditional Centrex and supplementary services, such as group trumpet each other for, the number of hidden and restrictions, call forwarding, call barring, grouping ring, and can take full advantage of the IMS (IP Multimedia Core Network, subsystem, the IP network multimedia subsystem) architecture and business expansion, flexibility and openness, providing an environment conducive to business operations VPMN (virtual Pravite mobile network virtual Private mobile Network) business, whose main characteristic is to support multiple user access. In addition to Centrex services to IMS users, to users of a large number of the current network CS (circuit Service, the circuit domain business applications) the domain of mobile phone users, PBX (public fixed telephone network of small and medium switch) the integration of Centrex services, so as to provide cross-network, cross-regional, inter-terminal integration of Centrex services.IMS architecture and business expansion, open IP-based network to carry out the CM-IMS services are also faced with a variety of security threats. The user terminal’s IP address allocation, the user terminal, network access, the number of users, what terminal to meet the business needs of different users, how to ensure quality of service, how to pass through the NAT/Firewall, and how to solve the inter-carrier network access into, and so on; in addition to the traditional business factors also need to give further consideration to the business deployment of security: such as the protection of the business, including the availability of CM-IMS core system protection to ensure that the bearer network is available, to ensure the business terminal equipment available; also need to consider the terminal physical security, IP isolation, information leakage prevention, to prevent the misappropriation and misuse of the business.