u/voidrane

been noticing my streams buffering and dropping quality during peak hours for a while now. decided to actually test it instead of just complaining about it.

wrote a script that runs download tests to different cdn endpoints every 15 minutes and logs the results. it tests netflix's own oca (open connect appliance) nodes, a video cdn (cachefly, which serves a bunch of streaming platforms), and generic traffic endpoints like cloudflare and ovh as a baseline.

the idea is simple: if your isp is throttling video traffic specifically, video cdns will be noticeably slower than generic cdn traffic on the same connection at the same time. you cant fake that with normal network variance.

imgur.com/a/RZX34dT

results after 8 samples over a few hours:

- cloudflare (generic): ~20-31 mbps

- netflix oca (ipv4-c267-was001-ix.1.oca.nflxvideo.net): ~7-10 mbps

- video cdn (cachefly): ~12-18 mbps

- baseline average: ~17 mbps

netflix traffic is running at roughly 55-70% of the generic baseline consistently. not once during testing did netflix speeds match cloudflare speeds. the differential is too consistent to be random routing variance.

the script flags it as "differential rate limiting" with high confidence (8+ samples). the confidence qualifier matters because single-sample comparisons can be noisy, but 8 consistent data points with the same pattern is not noise.

for context this is spectrum, as11426, charlotte nc.

the frustrating part is that if you run a speedtest on speedtest.net or fast.com you'll get your "full" speed because those are either whitelisted or also owned by the isps being tested (fast.com is netflix's own tool so they presumably have an agreement). the throttling only shows up when you look at where the traffic is actually going.

if you want to run the same test yourself the script is straightforward python, just needs the requests library. it fetches a live netflix oca url via fast.com's api so it always hits your nearest netflix node.

not trying to start a legal battle just documenting what i found. curious if anyone else on spectrum has similar numbers.