Design And Implementation Of The Diameter Protocol Of IP Multimedia Subsystem

RADIUS is one of the most commonly used protocols in authentication and accounting at present, widely adopted because of its simplicity, security, easy-operation and fine extension. However, the protocol is not well suitable to the development of network due to its own defects such as the transport on UDP, simple mechanism of discarding, its lack of regulation for retransmission and centralized accounting service. Diameter protocol is resulted from the integration with kinds of network and development of the Internet itself, which is in urgent need of the new-generated AAA technology based on IP.Network architecture of IMS is analyzed systematically. Diameter protocol is studied. Moreover, software architecture of the Diameter of Xi'an Datang Telephone Corp and some related modules are designed and implemented. To begin with, the document gives a brief introduction of Diameter protocol. Then, according to its feature, the Diameter Base protocol and application protocol are designed respectively. In its overall design, Diameter Base protocol is divided into separate function modules, of which the logical relationships and functions are defined. Also, it designs the main data structure and the model. At last, Cx interface based on the Diameter protocol can be attributed to six procedures, which are finally fulfilled by the designed interface.Diameter protocol will be applied to more interface of IMS.