How this differs from a speed test
A speed test measures TCP, where lost data is simply resent and you only see throughput. Voice travels over UDP: a lost packet never comes back and a late one is useless. So we send a real voice stream, one packet every 20 ms sized for the chosen codec, without retransmission, and count what was lost, what was late and how it would sound.
How it works
Two WebRTC peers in your browser connect only through a Cloudflare TURN server. Packets go from you to the nearest Cloudflare node and back, along the same path a call to a PBX or carrier in that region would take. The data channel is unordered with no retransmissions, like UDP. MOS follows the ITU-T G.107 E-model.
VoIP targets
- Loss under 1%, with no long bursts (more than 3 packets in a row is audible).
- Jitter under 30 ms.
- One-way delay under 150 ms (round trip is shown here).
If you already have calls, load a capture into the pcap analyzer. MOS for other conditions comes from the MOS calculator.