Real-world: VoNR call quality troubleshooting

Measuring VoNR Voice Quality

VoNR call quality is measured using the MOS (Mean Opinion Score) scale from 1 (bad) to 5 (excellent). Target for VoNR with EVS codec is 4.0-4.5 (toll quality). AMR-WB typically achieves 3.5-4.0 (acceptable). Scores below 3.0 indicate poor quality and trigger user complaints. Three key metrics drive MOS scores: jitter (variation in packet arrival time, target under 30ms — high jitter causes choppy audio), end-to-end delay (mouth-to-ear latency, target under 150ms — above 400ms makes conversation difficult), and packet loss (lost RTP packets, target under 1% — above 5% causes noticeable audio…