Why time-based streaming?
A fixed file can be too small for fast networks and wasteful on slow ones. Time-based streaming provides a consistent observation window while bounded browser buffers prevent runaway memory use.
Why warm up first?
The warm-up lets transport behavior and buffers settle before counted bytes begin. It is excluded from the reported throughput.
How stability is calculated
The documented score combines throughput consistency, stall-free windows, latency consistency and connection continuity. It is application guidance, not an industry certification.