Policy-enabled quality of service (QoS) support for voice over wireless IP (VoWIP)

With the recent advancement in network technologies, many organizations are now exploring voice over IP (VoIP) or, in some cases, have begun to migrate to VoIP within their organizations. Many of these same organizations are also looking at wireless data communication as part of their core network infrastructure. It is therefore natural to begin to look at VoIP communications in which there is a wireless communication element. Given the inherent noise and variability in wireless communications, there are questions of performance and quality of the voice communication. This paper reports on studies of the use of VoIP over a wireless connection within a corporate network environment. We first report on the effectiveness of the communication, essentially quality of service (QoS) measurements, under different levels of connectivity to wireless access points. We then outline a policy-enabled Differentiated Services (DiffServ) architecture and services for providing predictable and measurable QoS support for VoIP. In particular, we show how our approach integrates policy management to allow on-demand allocation of network resources through dynamic prioritization of network traffic in response to violation of QoS requirements. The main focus of our research is on applications using time-sensitive data streams, such as video conferencing and IP voice services. In this particular paper, we look specifically at how such an approach can accommodate VoIP applications in a network environment involving wireless access points.