An Efficient and Robust Overlay Routing Scheme for VoIP

Even though voice over Internet protocol (VoIP) provides good call quality in most cases, there are occasions in which the delay, jitter and loss rate in the Internet exceeds the values tolerable for voice traffic. This leads to a degradation in voice quality or may cause a VoIP call to fail entirely. Overlay networks provide a solution to increase the quality of service (QoS) in the Internet. However, application-agnostic overlay networks cannot fully exploit the characteristics of VoIP traffic. In this paper, we propose a new overlay routing scheme for VoIP. By utilizing the signaling phase that precedes a VoIP call and passively monitoring VoIP flows, our VoIP overlay routing scheme can effectively select a route that meets a given quality of service criteria. It is robust in that it quickly reroutes traffic around network failures and efficient by creating only a minimal overhead through the tight integration with VoIP protocols