The Design And Implementation Of Session Control System For Convergent Networks

In recent years, with the new demands and new technologies emerging, the traditional service provided by a single network cannot meet the requirements of users, and the service converged across networks has become a trend. In the Implementation of convergent services, Session Call System (SCS) plays an important part and is the basic precondition for the services.This article first analyzes the system needs according to the function of the SCS and its role in the architecture of convergent service. Then this article explains it in two aspects:function needs and non-function needs. Among them, the function needs include the functions the system necessarily provides and the interfaces with external systems, and non-function requirements mainly include system reliability and expansibility.After analyzing the system requirements, this article first divides the SCS into several functional modules, then proposes design plan for each of them and explains the two key modules in detail for implementing this system:call control module, and service triggering module.Call Control module (CC) is the core of the SCS. This article first mainly introduces the signaling control model of the CC, which is Back-to-Back User Agent (B2BUA), then analyzes how to manage call, including the creation and maintenance of call instance. At last, it explains the design of state machine, such as the definition of states and the transformations between them.Service triggering module is an important part for implementing convergent services. This paper first analyzes some existing problems on the base of illustration of the current service triggering mechanism, then does some research and comparison for some services triggering mechanisms in internal and external countries, and proposes a new Service bases Service Triggering Mechanism (SSTM). It can change the order of service triggering dynamically according to the relationships of services, the state of services, and some other kinds of information related to service triggering. This mechanism can avoid the shortcomings of the current service triggering mechanism, and improve the flexibility and dynamic for service triggering.After completing the system design and implementation, this article describes the system operation environment, including hardware environment and software environment. In order to verify the system having been implemented whether meets the requirements of the main function, this article designs a series of test cases to test it. Finally, the paper summarizes the work the author have done and the work to be done in the future.