Enhancing Intra-Domain Scalability of IMS-based Services

IP Multimedia Subsystem (IMS) and IMS-based services are increasingly providing interoperable session control and mobility for next generation all-IP networks. However, clear design guidelines and techniques for the support of scalable IMS-based deployment, especially for data intensive services such as mobility management, presence, and instant messaging, are still missing. That could block or at least relevantly slow down IMS acceptance by network operators and application providers. To address these challenges, this paper thoroughly analyzes IMS scalability with special attention to intra-domain deployment issues. Then, it proposes a novel solution with three core original contributions toward intra-domain scalability: i) data-centric dissemination of session state with limited overhead; ii) service-aware routing for fast intra-domain load balancing; iii) service-aware load monitoring and component de-/activation for long-term intra-domain load partitioning at both service and infrastructure levels. The reported experimental results point out that our solution can significantly increase intra-domain scalability with very limited costs.