Rate-based SIP flow management for SLA satisfaction

SIP flow management should respect the specific characteristics of SIP protocol applied in multimedia or telecom services for meeting stringent quality of service (QoS) requirement. The specific characteristics include explicit session structure for correlating a series of SIP messages, stringent response time required by real-time applications, extra overhead imposed by SIP message retransmission, service differentiation for meeting different business demands. We designed a front-end flow management (FEFM) system for SIP application servers to address these issues. We present the overall architecture of FEFM, the functionalities of primary modules in FEFM and the evaluation results in this paper. The evaluation results show that FEFM has the ability to achieve the tradeoffs among overload protection, QoS assurance and service differentiation.