Tolerance of Highly Degraded Network Conditions for an H.323-Based VoIP Service

摘要

he empirical work presented here concerns the effects of very large packet loss and delay conditions upon the performance of an H.323-based VoIP service. Specifically, it examines call establishment performance and audio voice quality under these conditions. The work was performed as part of an investigation concerning the effects of GEO satellite environments upon H.323-based VoIP, but its findings are relevant to all kinds of networks which may suffer or become subject to highly aberrant transmission conditions. The call establishment tests showed that the H.323 protocols could establish calls successfully under severely impaired conditions. The listening tests showed that uncontrolled jitter was the most destructive parameter to listening quality. Packet loss was also influential, though somewhat less dramatically.