Netflix Makes Up Almost Half of US Downstream Traffic

Netflix continues to be the top traffic generating service online in the US, accounting for 32.69 percent of all downstream traffic, according to a new report from Sandvine.

Regular HTTP traffic comes in at a respectable number two with 17.48 percent of peak downstream traffic.

YouTube is responsible for quite a large chunk of downstream traffic as well, 11.32 percent in the US. BitTorrent is only at number four when it comes to downstream traffic, with 7.62 percent.

What's the most impressive is the fact that Netflix traffic rose 10 percent points in the last half of year, despite losing 800,000 subscribers in the past few months.

Things are different for upstream traffic, due to the peer-2-peer nature of BitTorrent traffic, it makes almost half of all upstream traffic in the US, 47.55 percent.

HTTP traffic comes at a very distant second, with 11.45 percent. Strangely enough, Netflix also makes up 7.69 percent of upstream traffic, despite the fact that traffic should be fairly one-directional on the site.

The video streams account for the vast majority of Netflix traffic and those come from the Netflix servers to the users and not the other way around.

The report explains that all of this traffic comes from ACK TCP packets alone, the messages sent by the receiver acknowledging that the incoming packages, with the video data, have arrived.

Skype, which also uses a p2p architecture to cope with the huge amounts of traffic it sees, is the fourth largest source of upstream traffic in the US.

You'll notice that traffic on the internet is coming less and less from the trusty world wide web and more from media services. Granted, both YouTube and Netflix on the web, but they traffic they generate comes mostly from the large video files they stream.