QoS control using an end-point CPU capability detector in a secure VoIP system

Security is a serious bottleneck for the future of VoIP. Because of the time-critical nature of VoIP most of the same security measures currently implemented in today´s data networks could not be used in VoIP networks. Two main factors affect voice traffic over secure IP channels. The first is the time required to encrypt payload and headers and the construction of the new ones. The second is the increased packet size because of the headers added to the original IP packet. Techniques that could be adopted to overcome these two problems in addition to the compression QoS issues associated with audio codecs put more strain on end-point CPU´s. In this paper we propose a new QoS control scheme that uses a simple protocol to detect the end-point CPU capabilities, and according to this information, we choose dynamically the most suitable techniques for the transmission of voice over a secure IP channel to provide a superior QoS control performance, in terms of perceived speech quality.