International Journal of the Computer, the Internet and Management (IJCIM)
In this paper, the authors report the results from the study about perception of Thai users to the voice quality of VoIP provided by two codecs, G.711 and G.729, referring to packet loss. The conversation-opinion tests have been conducted with 250 participants to obtain the Mean Opinion Score. This paper found that the user perception to G.711 and G.729 is not different significantly referring to the packet loss rates of 0%, 2%, 6%, 10% and 20% approximately. However, the trend of the difference is increased according to the increment of packet loss rates of 10% and 20% in the network.