Measurement and analysis of users' perception of QoS for IP telephony service

Along with a technological evolution of the Internet that enables providers to offer ever-higher access speeds, applications' demands for the quality of service (QoS) are growing as well. Services like IP telephony are highly dependent on the quality of the transport services as well as the application QoS-awareness. Users' acceptability of the service and their willingness to pay is depending on their perception of the service and its quality. Therefore is users' perception of the offered service and its quality important for the provider, so he can adjust and design his network to fulfill users demands. This paper presents the results of the subjective testing of a user perception of a quality that IP telephony service is delivered with. Both listening and conversational tests are considered. The results are further used to test the existing commercial QoS mechanisms and their suitability for the immediate service offering. The analysis of tests enables a provider offering IP telephony to understand not only technical features of the service, but also to recognize the users needs, behavior and their acceptance of the service and its quality. Furthermore, test results may be used as a basis when designing a network supporting the IP telephony service while using existing QoS mechanisms.