DA VINCI: A tool to improve VoIP call routing configurations

As IP telephony becomes a critical part of the enterprise network infrastructure, there is an increasing need for tools to help manage VoIP systems. In this paper, we introduce DA VINCI, a tool to manage VoIP call routing — the core of VoIP configurations that determines how calls are routed inside the enterprise or between the enterprise and external networks. We first establish the complexity involved in call routing design and configuration by studying characteristics of nine large enterprise VoIP networks. We then develop methodologies to improve and simplify call routing configurations by (i) identifying common design patterns, i.e., shared resource routing and local resource routing, so that administrators can better understand and reuse existing call routing designs, and (ii) removing unused and superfluous configurations from dial plan designs while retaining the correctness of operations. All of our techniques are incorporated in the DA VINCI tool that has been deployed in more than ten enterprise networks to help administrators streamline VoIP maintenance through extraction, analysis, simulation, and configuration of call routing.