A scalable architecture for SIP infrastructure using content addressable networks

Session initiation protocol (SIP) provides call establishment functions for VoIP. These functions are highly CPU-intensive and hence need to be distributed over multiple servers in order to support the peak workload. Existing approaches to this problem are unfortunately not scalable or fault-tolerant, incurring high maintenance overheads or introducing a single point of failure. This paper presents a proof-of-concept design and analysis of a scalable, robust architecture for SIP infrastructures using a content addressable network (CAN) model, called CASIP (CAN-based SIP). The performance study of CASIP using real implementation of a SIP stack and NS-2 shows that the proposed system distributes the SIP processing (both update and lookup) load over multiple nodes very effectively without incurring much routing and maintenance overhead.