The Research Of Service Congestion Of Softswitch

With the process of network technology and the increase of user services, Next Generation Network based on the softswitch has been a hotspot in the current development of network. Multimedia services such as voice, fax, text, image, video and so on have more and more richer, and become main services in the communication. The requirement of quality of service in the multimedia services has more and more increment and the guarantee of quality of service of multimedia services will be rapidly developed. But Internet can only provide best-effort services for transmission of data and it's weak in the management of traffic, delay and bandwidth. So it's not good to transfer the new services with the quality of service guaranteed such as voice and video etc. In the recent years, IETF(Internet Engineering Task Force) has engaged in a lot of researches in the quality of service guaranteed in the network and puts forward many solutions. But those solutions have not considered the state of congestion in the network. If only considering the guarantee of QoS, the same class data flow will go in the same way, then congestion will occur in some link. Moreover, only considering the guarantee of QoS, the utilization of the resources in the network will not probability reach a high level. This thesis outlines the present status and development trend of telecom network and gives an introduction to the softswitch-based next generation network. It also provides an overview of softswitch protocols and a comparison of each other. The implementation of softswitch is discussed from aspects of network migration, service evolution and network interoperability. The main technical problems in softswitch applications are briefly discussed. By the analysis of QoS control technologies, a new algorithm called QoS routing algorithm based on congestion is proposed and congestion degree is imported. Besides the guarantee of QoS of the services, this algorithm analyzes congestion degree of each node in the network and avoids the link of high congestion degree in the routing. Load in the network will be adjusted to a balance level. From the graph of the relationship of the power and load, to make the utilization of resouces in the network best, the congestion degree should be retained up to an appropriate level. QoS routing algorithm based on congestion can adjust the access of user by the setup of congestion degree and make the allocation of resouces in the network more effective. It's a good routing solution to transit from IP network to NGN.