Using overlay networks to improve VoIP reliability

Real-time traffic requires rapid corrective action to counteract the negative effect of network faults. In this paper we propose such a detection and rerouting scheme for VoIP traffic. We use an RTP/RTCP-based detection method to quickly detect network problems. Subsequent packets can then be rerouted using an overlay network approach that avoids failed links and paths with inadequate QoS. This rapid detection and rerouting minimizes the impact of network failures to real-time applications such as VoIP. In this paper, we present the main ideas behind these proposals along with some implementation considerations.