One-way-delay (OWD) is measured using audio signal in Abacus. Users can only measure OWD using QOM (PSQM or PESQ) path confirmation. During the measurement, the sending side will send a pilot tone. On the terminating side, the pilot tone is detected, and the difference in timing is reported as OWD. This methodology does not depend on the underlying signaling interface and protocol. Because of this, the feature is available on all protocols that support QOM measurement.