A performance benchmark and bottleneck analysis of IP multimedia subsystem

IP Multimedia Subsystem (IMS) is an All-IP architecture for telecom networks which provides a layered platform to reduce the costs associated with deployment and delivery of rich multimedia services. Considering the strict service requirements and the large subscriber base of telecom environments, the performance and scalability of IMS would be of critical importance. In this study, with the aim of evaluating the operation of IMS during high workloads, we deployed an IMS test-bed based on the open-source software solutions, and applied extensive performance configurations to the involved subsystems. Then, we conducted benchmark experiments targeting both the IMS control and service layers. The results demonstrate that Home Subscriber Server (HSS) and Serving-Call Session Control Function (S-CSCF) could be potential bottlenecks for performance and scalability of IMS.