In the second annual Cisco Global Cloud Index (2011-2016), Cisco forecasts global data center traffic to grow fourfold and reach a total of 6.6 zettabytes annually by 2016. The company also predicts global cloud traffic, the fastest-growing component of data center traffic, to grow sixfold - a 44 percent combined annual growth rate (CAGR) - from 683 exabytes of annual traffic in 2011 to 4.3 zettabytes by 2016.

For context, 6.6 zettabytes is equivalent to:

• 92 trillion hours of streaming music - Equivalent to about 1.5 years of continuous music streaming for the world's population in 2016.
• 16 trillion hours of business Web conferencing - Equivalent to about 12 hours of daily Web conferencing for the world's workforce in 2016.
• 7 trillion hours of online high-definition (HD) video streaming - Equivalent to about 2.5 hours of daily streamed HD video for the world's population in 2016.

The vast majority of the data center traffic is not caused by end users but by data centers and cloud-computing workloads used in activities that are virtually invisible to individuals.

For the period 2011-2016, Cisco forecasts that roughly 76 percent of data center traffic will stay within the data center and will be largely generated by storage, production and development data. An additional 7 percent of data center traffic will be generated between data centers, primarily driven by data replication and software/system updates.
The remaining 17 percent of data center traffic will be fueled by end users accessing clouds for Web surfing, emailing and video streaming.
From a regional perspective, the Cisco Global Cloud Index predicts that through 2016, the Middle East and Africa will have the highest cloud traffic growth rate, while the Asia Pacific region will process the most cloud workloads, followed by North America.

Overview of the Latest Worldwide Market Study:

• The Cisco Global Cloud Index (2011-2016) was developed to estimate global data center and cloud-based Internet Protocol (IP) traffic growth and trends. The Cisco Global Cloud Index serves as a complementary resource to existing network traffic studies, providing new insights and visibility into emerging trends affecting data centers and cloud architectures. The forecast becomes increasingly important as networks and data centers become more intrinsically linked in offering cloud services.
• The Cisco Global Cloud Index includes a "workload transition" forecast, which shows the workload shifting from traditional data centers to more virtualized cloud servers.
• The forecast also includes a supplement on Cloud Readiness Regional Details, which examines the fixed and mobile network abilities of each global region (from nearly 150 countries) to support business and consumer cloud-computing applications and services.
• The Cisco Global Cloud Index is generated by modeling and analysis of various primary and secondary sources, including 40 terabytes of traffic data sampled from a variety of global data centers over the past year; results from more than 90 million network tests over the past two years; and third-party market research reports.

"As cloud traffic continues to proliferate in a new world of many clouds, the Cisco Global Cloud Index provides all cloud computing stakeholders with a very valuable barometer to make strategic, long-term planning decisions. 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. 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," said Doug Merritt, senior vice president, Corporate Marketing, Cisco Systems.