Cloud traffic will soon be dominating data centers, according to new research from Cisco Systems (CSCO). The networking giant's Cisco Global Cloud Index (2012 – 2017) forecasts that cloud traffic will be the fastest-growing part of overall data center traffic over the next five years, with a 35 percent combined annual growth rate (CAGR).

Considering how quickly consumers and businesses are shifting to the cloud, even in small ways, high cloud traffic growth within the data center probably comes as little surprise. But here's what this really means in terms of bandwidth being consumed. In 2012, cloud represented 1.2 zettabytes (ZB) of traffic. By 2017, it's going to consume 5.3 ZB of data center traffic every year. Total data center traffic in 2017 will reach 7.7 ZB.

For those of us who haven't even wrapped our brains around petabytes, let alone exabytes or zettabytes, Cisco offered some perspective. For instance, 1 ZB (1 billion terabytes) would be equal to:

Only about 17 percent of this cloud traffic will be fueled by end users accessing the cloud for web surfing, video streaming, collaboration and connected devices. Instead, the vast majority of the traffic will be caused by data centers and cloud workloads used in activities invisible to end users.

"People all over the world continue to demand the ability to access personal, business and entertainment content anywhere on any device, and each transaction in a virtualized, cloud environment can cause cascading effects on the network," said Doug Merritt, senior vice president of Product and Solutions Marketing at Cisco, in a prepared statement. "Because of this continuing trend, we are seeing huge increases in the amount of cloud traffic within, between and beyond data centers over the next four years."

IT professionals of the future will have their work cut out for them as the cloud continues to become a huge user of public and private network bandwidth.