2009 Reports

Mouth-to-Ear Latency in Popular VoIP Clients

Agastya, Chitra; Mechanic, Daniel; Kothari, Neha

Most popular instant messaging clients are now offering Voiceover IP (VoIP) technology. The many options running on similar platforms, implementing common audio codecs and encryption algorithms offers the opportunity to identify what factors affect call quality. We measure call quality objectively based on mouthto- ear latency. Based on our analysis we determine that the mouth-to-ear latency can be influenced by operating system (process priority and interrupt handling), the VoIP client implementation and network quality.