Cable operators still provide higher throughput on average than telcos when it comes to streaming Netflix video content over the Internet, with Charter Communications turning in the best performance from January through May 2011, according to the movie rental company.
Netflix on Tuesday published updated rankings of U.S. Internet service providers on its corporate blog.
The rankings -- based on Netflix's own monitoring of each ISP -- show Charter with the best performance over the five-month time period, consistently turning in more than 2.6 Megabits per second. Also in the top tier are Comcast, Time Warner Cable, Cable One, Cox Communications, Suddenlink Communications and Cablevision Systems.
Verizon falls notably below the top MSOs, hovering at about 2.2 Mbps, and AT&T, CenturyLink and Windstream were less than 2 Mbps. Frontier Communications and wireless broadband provider Clearwire were both less than 1.6 Mbps.
Netflix first published ISP rankings in January 2011. On that list, Charter also came out on top.
Critics have previously pointed out that Netflix's ISP rankings lump Verizon's FiOS fiber-to-the-home and AT&T's higher-speed DSL service together with traditional DSL -- so there was not a direct comparison between cable and the telcos' more advanced networks.
Netflix says it is addressing that issue. In the blog post, director of content delivery Ken Florance acknowledged that the combined rating for DSL and fiber-to-the-premises networks was "due to a limitation in how we collect data, which we will resolve soon, so you can expect the DSL and Fiber offerings of these ISPs to be represented separately in future updates."
While Netflix had previously included several Canadian ISPs, it has excluded them in this go-round.
"This data has become less significant for Canada in the wake of Netflix reducing default bit rates in Canada to help our Canadian members who are subject to low bandwidth caps," Florance wrote.
In North America, Netflix streaming video accounted for 29.7% of peak downstream Internet traffic and has become the single largest source of Internet traffic overall, according to a March study by bandwidth-management vendor Sandvine.
As of the end of March, Netflix had 23.6 million subscribers in the U.S. and Canada, after adding a net 6.67 million in the previous six months.