Quality assessment of secure VoIP communications

Voice and telephone communications over IP networks are nowadays known as well established technologies, especially from the point of view of protocol architecture and voice compression algorithms. However, there are still several aspects in their security that need to be investigated. A personal voice communication should ensure authenticity and privacy; they may be provided by means of different solutions, featuring different security performance and impact on voice quality. This paper investigates many of the security mechanisms available in the field of Open Source VoIP communications, according to the specific protocol architecture selected for implementation, and provides an extensive evaluation of their impact on quality, by considering a number of network traffic related parameters. In details, the quality of conversation is tested, and expressed by the mean opinion score parameter, by varying network traffic conditions, in the secure and not secure cases.