Research On The Load Control Algorithm For Media Gateway In Softswitch

Compared with the traditional network, quality of service is an important issue that softswitch network faces. It directly affects the quality of service of entire network. In essence, the softswitch network will not solve the problem of service quality. There are three solutions: the first, providing of adequate network bandwidth. This approach seems simple, but in network planning, must consider the relationship between cost and quality of service. And network traffic is a dynamic parameter, the capacity may be dynamically adjusted, and increasing with the mobility. The distribution of business quantity is also a dynamic parameter, so accurate network planning has certain difficulties. The second, assigning a dedicated network for high priority, it can be used in the early application of softswitch network. But this does not meet the original intention of the softswitch network, and can not fundamentally solve the service quality of the high priority. The third, proposed by the IETF, including InterServ model, DiffServ model and MPLS solutions. The three solutions need to coordinate with each other and implement together in the whole network. In different levels of network, use different solutions to ensure service quality of the business from end to end. Therefore, the quality of service issues in softswitch network has yet to be studied further.Media gateway is located in the access layer of softswitch network, and the various users and network accessed to the transport layer, while the media gateway is controlled by softswitch that is in the control layer. Media Gateway as the most direct equipment that provides service to user, all business should be through it to achieve. Good load control mechanism will be conducive to the stability of the entire network, its performance also directly determines the quality of service in softswitch network. Therefore, can use the load control of the media gateway to improve the quality of service in softswitch network.View of the above problems, there are main works as follows:1. This paper first introduces research status of the load control of media gateway in softswitch network, and then introduces the softswitch and media gateway technology, and media gateway control protocol H.248 is introduced in detail. While in-depth analyzes the existing load control algorithms, including overload control algorithms and access control algorithm, and gives the load control structure. These lay the foundation for the algorithm of this paper.2. On the base of the first part, this paper according to separation characteristics of control and bearer in softswitch, focus on the relevant issues of media gateway overload control, including media gateway overload detection, dynamically select the best media gateway, and the mixed overload control algorithms for different business.3. In order to improve system stability, this paper makes the overload control and access control closely integrate, and improve informed adaptive admission control algorithm based on blocking probability threshold, in order to better control the media gateway load.Finally, simulate the media gateway load control algorithm using the simulation tool, the results show that the proposed and improved algorithm can well control the media gateway traffic, and improve system stability, thus ensuring the quality of service.