Quality Evaluation Methods to Improve Enterprise VoIP Communications

In the last few years there has been a dramatic development in voice communications technology with a significant move towards Voice over the Internet Protocol (VoIP). Since the Internet was primarily designed as a besteffort technology, good quality conversation and intelligibility are not guaranteed. In this paper we address quality evaluation of voice communications in the context of modern enterprises using VoIP as an emerging technology with impact in their activity. Relevant factors for service providers and enterprises using VoIP technology are described, such as those related to measurement of intelligibility and evaluation of overall voice communications quality. Also, the most relevant voice quality evaluation methods recommended by the ITU-T are described along with the main features that can be used to improve voice communications. Fundamental concepts are presented, such as intrusive, non intrusive, objective, subjective and parametric methods. Mastering the concepts of such emerging technology, has recently lead to research and development of a model-based voice quality monitor for VoIP services. After its successful implementation, it is now fully operational in a Portuguese telecom operator.