VoIP Mos Score Testing Tools

Originally published at vicistack.com . Follow us for more call center engineering content. Last updated: March 2026 | Reading time: ~22 minutes Your agents are complaining about call quality. Customers sound robotic. There's echo. Words get clipped. Your manager wants a number that proves the calls are bad, and your carrier wants a number that proves they're not responsible. That number is the MOS score — Mean Opinion Score — and it's been the standard metric for voice quality since 1996. The problem is that most people who talk about MOS scores have never measured one. They parrot the "4.0+ is good, below 3.5 is bad" line without knowing how to produce the number in the first place. I'm going to show you exactly how to measure MOS scores on your VoIP/VICIdial system using tools that range from free (Wireshark, Asterisk CLI) to expensive (POLQA hardware probes). You'll leave here with actual testing procedures, not marketing copy. MOS Score Basics (The 60-Second Version) MOS was origi