The Implementation And Application Of Protocol H.248 In DaTang Telecom's SS3000 Softswitch

NGN (Next Generation Network) provides the direction of network development. It is an integrated network architecture can provides multi-service such as speech, data and multimedia. NGN has many characteristics, such as opened architecture, service-driven network, uniform protocol based and packet based network, and so on. Softswitch is core entity of NGN, which functions real-time service control, call control and connect control.SP30 PSTN switch is the digital and program controlled switch which is product of Datang Telephone's corp based on norrow-band circuit-switch platform. It is sensitive to make the SP30 PSTN switch a smooth transition to NGN, which prolong and enhance the life of the product and protect the investment of operator and product vendor.This paper represent the research task how SP30 PSTN switch smoothly transit to NGN and give details about the development of core protocol-H.248.This paper tells the background of NGN and Sp30, system analysis, software design and some data structures and algorithms needed in implementation,In our project development, I am responsible for the design and implementation of H.248, the core protocol of Softswitch.The functions of protocol implement consist order implement, connection control of MC and SoftSwitch (startup, registeration, logout, failure, living minitoring) and connection function.So the paper tells much of the description of the protocol, and details of design and coding.