Research And Implementation Of Load Balancing Scheme For VOIP System

At the end of 21^st century Internet made surprised success and became another worldwide communication network after PSTN. With these years' development, IP technology has become one of the key technologies in future network and IP based packet switch has been the mainstream. Now information network based on the multimedia communication has become the focus all over the world. VoIP(Voice over IP) is one of the multimedia services under this background and has access great success and wide application, also it is a cheering omen of the emergency of the next generation network.In one hand, because of the cheap communication price and the acceptable audio quality, VoIP's market is growing bigger and bigger. This requires high capacity servers. In another, the reference design model in the H.323 standard is too simple to satisfy the growing needs. This requires a redesign of the network architecture.In this thesis, we propose a cluster scheme for gatekeepers. This scheme contains the key view of the widely used cluster system design, and especially the high available cluster system under linux. In system designing, each part of the system is designed separately to divide the control and proxy function. This is a scheme that provides scalable services, and also ensures the owarding speed of data.At first, we will discuss the composition of the VoIP system, especially the details of H.323 protocol. The traffic load analysis for different part of the whole network and a reference flow of call signaling has been introduced. Then the concept of cluster systems is described, and we will review a famous project LVS, a cluster sytem solution under linux. In the following, based on the specifications of the load in H.323 network, and learning from the VS/NAT solution provided by LVS, the final design is proposed. At last the system is analyzed, in terms of Performance, Scalability, Availability, Cost-effectiveness.