MOS Score have always been very important to VoIP implementation. When 3CX was largely premise base, the MOS score represented the client site to the ITSP and so out of scope for 3cx. Now that 3CX in a datacenter is preferred, Client location to 3cx datacenter is important. https://en.wikipedia.org/wiki/Mean_opinion_score Please implement MOS scoring within 3CX. Either as a one time test like through the client firewall test or better yet integrated into the SBC. From the 3cx control panel, an administrator should be able to initiate a MOS score request to determine the internet quality the IP phones are experiencing from their client location.