In addition to now measuring upload speed and idle latency, it also
measures latency under load. The blog post announcing the change also has a
shout out to bufferbloat.net
It's nice having another option than just DSLReports to point people to
when they want to measure their bufferbloat.

https://media.netflix.com/en/company-blog/fast-com-now-measures-latency-and-upload-speed