Research on load balance of Service Capability Interaction Management

With the evolution of the IP Multimedia Subsystem (IMS), service interaction and management has received an increasing amount of attention. Service Capability Interaction Management (SCIM) is introduced as a component of Service Delivery Platform (SDP) for providing service interaction of IMS. Although there is much work on the standardization of SCIM, architectures based on industry standards like IMS may still have problems, especially the load balance issue, which has been seldom mentioned and discussed. Limited application servers become the bottleneck that affects the quality of service (QoS) due to the rising traffic levels. SCIM should provide load balance function among homogenous application servers to improve the performance of the whole system. We propose a module called Load Balancer that handles service messages from Call Control Network and sends each message to the optimal application server (AS). Four components of this module Load estimator, Load analyzer, Load Policies Center and Dispatcher cooperate together to implement the load balance function. This paper introduces load balance problem of SCIM from the network architecture viewpoint, then describes a load balance model and the mechanism of load balance. It discusses the concept and content of Load Policies which provide the necessary information for deciding the optimal AS to implement the load balance. Then it provides a load balance algorithm and the effectiveness is validated through simulation.