VoIP QoS Performance Evaluation in a Commercial Environment

(PREVIOUS TITLE: VoIP QoS Performance Evaluation in an Industrial Environment) Though the necessity and importance of quality guarantees for voice over IP network (VoIP) are well understood and studied by research groups, it has not been done much to evaluate and measure the quality of service (QoS) for VoIP in a practical industry environment. This study focuses on an evaluation of media gateway performance, in terms of voice quality, affected by impairments of an IP network in a practical environment. To study critical elements that affect voice quality in general, two end-to-end VoIP networks are built in NGN Interoperability Lab. Various IP network impairments, such as IP network delay, jitter, and packet loss are introduced into these systems for assessing the IP network impact. The performance metric is the end-to-end voice quality. This paper presents the end-to-end VoIP test-bed architecture, the test configuration, the experiment methodology, testing tools, analytical results, and testing results. The performance results are viewed from a user's perspectives in terms of PSQM and speech latency. Finally, the paper points out the crucial factors that affect a successful VoIP network. Some possible remedies are suggested.