Efficient Failover and Load Balancing for Dependable SIP Proxy Servers

Abstract

In this paper, we designed and implemented a dependable SIP-based clustered architecture for VoIP and multimedia applications, and also proposed an efficient OpenAIS-based SIP Load Balancing strategy (OSLB) that can balance proxy servers' load and achieve fast failover by reducing the number of failed calls when one of the dispatchers or one of the SIP proxy servers crashes. Experimental results show that our OSLB is comparable to an existing work, SIP load balancer, in terms of load balance metric (1.05 vs. 1.04). However, our OSLB reduces the number of failed calls by 86% when a proxy server failed compared to the SIP load balancer. This work, which is part of an EPON project, has been realized in an industry standard ATCA-based platform to provide high availability carrier-grade services, and is currently under a field trial In an ISP.