Fast method for evaluating VoIP speech quality in network backbone

This paper introduced a new passive method for VoIP speech quality evaluation,which helped to monitor service quality for parallel VoIP conversations in network backbone.Based on packet sniffing and flow tracing mechanism,this method measured several performance metrics(such as IPLR,RTT) for each VoIP conversation,and calculated the R and MOS value with a fast model.Test result shows that this method workes with high efficiency and accuracy.