An Empirical Evaluation of VoIP Playout Buffer Dimensioning in Skype, Google Talk, and MSN Messenger

Abstract

VoIP playout buffer dimensioning has been long a challenging optimization problem as the buffer size should maintain a balance between the conversational interactivity and speech quality. One of its challenges comes from the fact that many factors may a®ect the overall conversational quality, and some of the factors may change over time. Although academic researchers have done numerous e®orts in solving this problem, how their research results are applied in practice remains unknown.

In this paper, we investigate whether a gap between VoIP researchers and practitioners, from the perspective of playout buffer dimensioning algorithms, exists. Targeting at three popular VoIP applications, namely, Skype, Google Talk, and MSN Messenger, we design experiments to systematically measure how the applications adjust their playout buffer sizes. By using an objective QoE (Quality of Experience) metric, we show that all of the three applications do not adjust their buffer size very well. In other words, they could provide better QoE to users by simply replacing their buffer dimensioning algorithms. Also, all of them do not adapt the buffer size to the network loss rate, which should also be considered for optimal QoE provisioning.

Citation

Chen-Chi Wu, Kuan-Ta Chen, Chun-Ying Huang, and Chin-Laung Lei, "An Empirical Evaluation of VoIP Playout Buffer Dimensioning in Skype, Google Talk, and MSN Messenger," ACM NOSSDAV, June 2009.

Bibtex

@inproceedings{wu09:playout, author = {Chen-Chi Wu and Kuan-Ta Chen and Chun-Ying Huang and Chin-Laung Lei}, title = {An Empirical Evaluation of {VoIP} Playout Buffer Dimensioning in {Skype}}, booktitle = {Proceedings of ACM NOSSDAV 2009}, year = {2009} }

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