Voice over IP (VoIP) Mean Opinion Score (MOS) is a measure of the perceived quality of voice communications over internet protocol networks. It’s values range from 1 to 4.4 and is calculated from average latency, jitter and packet loss. The formula used is based on ITU-T Recommendation G.107.
The following guide to MOS values can be used to determine VoIP quality:
4.4: Best score possible
4.3 – 4.4: Users very satisfied
4.0 – 4.3: Most users satisfied
3.6 – 4.0: Some users satisfied
3.1 – 3.6: Many users dissatisfied
2.6 – 3.1: Nearly all users dissatisfied
1.0 – 2.6: Not recommended