xk6-sip: Audio Quality Testing in VoIP/SIP Load and Functional Tests

This article explores xk6-sip, an extension for the k6 load testing tool designed to automate audio quality verification in VoIP/SIP systems. The author highlights that standard testing tools often focus solely on signaling (SIP), ignoring the actual state of the media stream (RTP). This can lead to false positives where a call is marked as successful despite the user hearing silence, noise, or incorrect audio due to NAT issues, media server congestion, or transcoding errors. Unlike traditional approaches that require manual comparison against reference recordings, xk6-sip integrates quality checks directly into k6 scripts. This enables automated audio stream evaluation during both functional testing and high-load scenarios, providing a more accurate simulation of the real user experience in contact centers and telecommunications infrastructure.