Download, upload, latency and bufferbloat — measured, not estimated
Measures the path between this browser and ip.tmflix.com — the origin is in Helsinki, reached through Cloudflare. It is a real measurement of your connection to this server, not a nearest-server ISP benchmark, so treat it as a floor rather than a ceiling.
The first ~1.2 s of each phase is TCP slow-start and is excluded from the headline figure. A line that ramps and holds is a healthy link; one that spikes then sags is not.