6/17/2008 -- Remember the days when bandwidth was cheap? When service providers (and even many private organizations) purchased hundreds of kilometers of dark fiber and had oodles of capacity to spare?

If a new study from Cisco Systems Inc. pans out, they soon won't have much, if anything, in reserve.

According to Cisco's Visual Networking Index (VNI) Forecast for 2007-2012, a perfect storm of technology trends (i.e., social networking applications and triple-play entertainment services) will help drive a sharp uptick in IP traffic.

Cisco called this perfect storm "visual networking" and warns that it could place unprecedented demands on global networking infrastructure.

In fact, the VNI Forecast projected, IP traffic will increase at a 46 percent compound annual growth rate between 2007 and 2012. The upshot, Cisco predicted, is worldwide annual bandwidth in the 522 exabyte range.

Just in case you're wondering what comes after an exabyte, it's a zettabyte. And if Cisco officials are right, you'd better start boning up on your zettabytes.

"The broad and increasing adoption of visual networking is having a significant impact on IP traffic growth for both consumer and business services markets worldwide," said Suraj Shetty, vice president of service provider marketing for Cisco, in a statement.

It's a whole new ballgame, Shetty said. "Until just a few years ago, 'exabyte' was an unheard-of term. However, because of the massive growth we're seeing, by 2012 we will have to reorient our vocabulary once again, as the metric that we need then will be the zettabyte."

Last year, for example, Internet video traffic jumped from 12 percent (in 2006) to 22 percent of global consumer Internet traffic, according to the Cisco study. That's just the beginning: By 2012, video-on-demand, IPTV, peer-to-peer (P2P) video and Internet video will account for nine-tenths of all consumer IP traffic.

The impact of visual networking will be less pronounced on the business side. Business IP traffic will grow at a 35 percent CAGR over the forecast period, Cisco projected.

By 2012, global IP traffic could reach 44 exabytes per month; in 2007, Cisco said, global IP traffic amounted to 7 exabytes per month. --Stephen Swoyer