— VoIP has widely been addressed as the technology that will change the Telecommunication model opening the path for convergence. Still today this revolution is far from being complete, since the majority of telephone calls are originated by circuit-oriented networks. In this paper for the first time to the best of our knowledge, we present a large dataset of measurements collected from the FastWeb backbone, which is one of the first worldwide Telecom operator to offer VoIP and high-speed data access to the end-user. Traffic characterization will focus on several layers, focusing on both end-user and ISP perspective. In particular, we highlight that, among loss, delay and jitter, only the first index may affect the VoIP call quality. Results show that the technology is mature to make the final step, allowing the integration of data and real-time services over the Internet.