QoS management for an enhanced VoIP platform using R-factor and network load estimation functionality

This paper presents the QoS management for an enhanced VoIP platform based on H.323/MGCP interworking. This enhanced VoIP platform bears a call agent/gatekeeper that centrally controls one or more media gateways. The QoS management is based on a software module that resides on the call agent, terminates and processes the RTCP stream of each connection and extracts the appropriate results. These results trigger the QoS management software module to instruct the call agent to take the appropriate actions in order to retain or to improve a certain voice quality for the connections. This is achieved by using the MGCP commands of the call agent and by changing the voice codec used on the connection so that the compression used for the voice packets is bigger and the bandwidth consumption is lower. The algorithm proposed for the QoS management is based on the E-model and the R-factor recommended by the ITU-T. This paper presents the structure of the QoS management module, the algorithm itself and outlines the architecture of the enhanced VoIP platform that uses this QoS module.