By 2017, wired devices will account for 45 percent of IP traffic, the network giant finds, while Wi-Fi and mobile devices will account for 55 percent. In 2012, wired devices still accounted for the majority of IP traffic, at 59 percent.

Some of that mobile traffic is increasingly ending up on fixed networks, due to trends like Wi-Fi offloading. Tablets and smartphones are already driving more than 20 percent of traffic on the fixed network.

Of course, the VNI report has to come with some humongous number to impress the media, so here goes: Global IP traffic, fixed and mobile, is predicted to reach 1.4 zettabytes per year -- a zettabyte being a trillion gigabytes -- by 2017. On a monthly basis, global IP traffic is expected to reach almost 121 exabytes by 2017, up from about 44 exabytes per month in 2012.

To put that in some context: The total amount of data traffic that passed over global networks in the year of 2008 is expected to cross networks in the course of a month in 2017.

Video junkies
To no one's surprise, Cisco pegs video as a primary driver of traffic growth, to the point where it's creating a "busy hour" of Internet traffic. "We're shifting more toward video, which is generally consumed in the evenings in most regions," says Arielle Sumits, Cisco's principal analyst for the VNI Forecast.

Prime-time Internet usage increased 41 percent in 2012, while average traffic grew at a rate of 34 percent, according to the report.

Managed IP video traffic will continue to grow, but over-the-top video traffic will grow far faster. Cisco expects the proportion of managed IP video is expected to stay flat (21 percent of total traffic in 2017, versus 21.8 percent in 2012) but says Web video traffic will jump to 52 percent of total traffic, from 38.3 percent.

— Dan Jones, Site Editor, Light Reading Mobile, and Mari Silbey, contributing editor, Light Reading Cable