Internal workloads, and not individual consumers, will continue to produce the vast majority of data traffic within the data center. That’s according to Cisco’s Global Cloud Index released Oct. 23. That study indicated that data center traffic will top 6.6 zettabytes by 2016—a fourfold increase from 2011. To frame it in more human terms: 4.3 zettabytes is the equivalent of 7 trillion hours of HD video streaming, or 2.5 hours of HD video per day for everyone in the planet for a full year. That’s 1,433,333 times the amount of data stored in the digital collections of the Library of Congress. Cisco concluded that the vast majority—76 percent—of data will stay within the data center and will be largely generated by storage, production and development data. An additional 7 percent of the data will actually be communicated between data centers itself, through data replication and software updates. End users will generate the remaining 17 percent via email, video streaming and Web surfing. “This year's forecast confirms that strong growth in data center usage and cloud traffic are global trends, driven by our growing desire to access personal and business content anywhere, on any device,” Doug Merritt, senior vice president of corporate marketing at Cisco, wrote in a statement. “When you couple this growth with projected increases in connected devices and objects, the next-generation Internet will be an essential component to enabling much greater data center virtualization and a new world of interconnected clouds." Arielle Sumits, one of the authors of the reports, said in a video that Cisco took ten data centers and analyzed all their internal and external traffic. The 2012 report analyzed 40TB of data, giving a more accurate forecast than last year’s, when 30TB were measured. The trend, Cisco said, was to process more workloads and more data in the cloud rather than within a company’s private data center (or, presumably, within a user’s PC). And the majority of traffic goes on behind the scenes. “A corporate Web site, for instance, they’ll be eight times more traffic within the data center and between the data centers than will reach the end user,” Sumits said. “A large multiple there. Other applications, such as our own WebEx for instance, where the multiple’s a bit lower.” Cloud traffic still makes up a mere fraction of the overall data center traffic, but it is growing faster: 44 percent CAGR, or sixfold, between 2011 and 2016, compared to the fourfold increase of data center traffic itself. Global cloud traffic will grow from 39 percent (57 exabytes per month and 683 exabytes annually) of total data center traffic in 2011 to 64 percent (355 exabytes per month and 4.3 zettabytes annually) of total data center traffic in 2016. Nearly two-thirds of data-center workloads will be cloud-based by 2016, Cisco found. The study found that while, the emerging region of the Middle East and Africa showed the highest potential for growth, North America generated the most cloud traffic (261 exabytes), followed by Asia Pacific (216 exabytes annually); and Western Europe (156 exabytes annually).   Image: asharkyu/