Wide Area Measurements of Voice Over IP Quality Revisited

Time, day, location and instantaneous network conditions largely dictate the quality of Voice over IP calls. In this paper we present results of VoIP quality mainly in terms of packet jitter and loss. This work revisits our objective of measuring VoIP quality in 1999 enabling us to make comparisons with the results we obtained three years ago. It also allows us to improve the measurement infra-structure we used previously through adding new functionality plus using more test sites. Furthermore we present findings on the influence of parameters such as packet size, asymmetry, silence suppression and location as well as much more comprehensive loss and jitter results. Our results conclude that the quality of Voice over IP sessions have improved over the last three years. In spite of this fact however, achieving acceptable global Voice over IP quality still remains a challenge.