Comcast claims otherwise, but I’ve tested and they definitely are limiting Netflix traffic on their Xfinity network. I tested this by streaming a Netflix movie to various devices – Blu Ray player, Computer, mobile device – on wired and wifi connections that get service from Comcast. All devices played haltingly and buffered so much it was impossible to watch the movie.
Netflix states that the minimum connection speed you really need to watch a movie is just 0.5 mbps. They recommend 1.5 mbps, and If you want HD: 5 mbps. My Comcast service claimed to be 25 mbps… but I was still having problems? This needed some testing.
First I checked with Comcast, who told me they don’t throttle Netflix, my connection was “great”, and maybe I should consider upgrading to a faster data plan to address “Netflix’s speed problem”, while their lowest-tier internet plan already claims enough bandwidth speed to stream 3 simultaneous Netflix movies in HD, and surf the web at the same time.
Faster service plans don’t offer a better minimum bandwidth speed, just a higher theoretical maximum speed – which I was never able to achieve anyway. If I test my bandwidth on speedtest.comcast.com using the nearest Comcast test server, I got close to my advertised speed. If I chose a more distant Comcast server the speed dropped remarkably (from 35mbps to 20mbps, when switching from a server in Detroit to New Jersey), and if I ran a non-Comcast speed test, it was even lower – averaging just 7-8mbps instead of the claimed 35mbps I should be getting.
Rebooting my modem and router helped, but didn’t solve the problem. My speed test results got faster after rebooting, but still weren’t hitting advertised speeds except in the nearest-Comcast-server test. But seriously: when you use the internet, do you think the content is coming right from your nearest large city? Maybe. Probably from much farther away – so the nearest-city test is rigged to show the best possible result, not the most realistic result. A realistic test would be measured from several heavy-traffic areas around the world, not just your nearest local server on the same network you’re using.
Configuring my router to use a VPN that encrypts traffic between my router and some non-Comcast endpoint (denying Comcast a chance to analyze my traffic) results in fast Netflix connections, no buffering and no interruptions in watching hours of Netflix movies, even though a speed test in that environment shows I’m still only getting 7-8mbps speed.
Using a VPN slows down traffic a little – there’s overhead involved in encrypting and decrypting it before it passes through Comcast’s network – but even then, I had no buffering problems. There are other benefits to using a VPN, especially if you use public wifi hotspots, but I’m not going into them here.
As other users connect/disconnect to the same VPN endpoint I was using, that server’s speed varied and at one point was not fast anymore – Netflix started buffering again. At that point I disconnected from that endpoint and chose another, and rebooted my router: problem gone.
I found an annual VPN service for just $35 in December 2013 via SlickDeals.net – unlimited traffic for a limited number of connected devices (mobile phone, laptop, etc). A router counts as just 1 device, and you can connect as many other devices to that router as you want, then they’re all benefiting from the encrypted connection and the device limit isn’t a big a deal.