data center traffic will expand four-fold to reach a total 6.6
zettabytes (one zetabyte [ZB] equals 1 billion terabytes [TB])
annually by 2016, according to the second annual Cisco Global Cloud
Index, which was released Oct. 23. The fastest growing component of
overall data center traffic, global cloud traffic
will grow six-fold-a 44% compound annual growth rate (CAGR), from
683 exabytes annually in 2011 to 4.3 zettabytes by 2016, Cisco
Providing some practical perspective, Cisco points out
that 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
- 16 trillion hours of business Web conferencing - Equivalent to
about 12 hours of daily Web conferencing for the world's workforce
- 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.
According to Cisco, the vast majority of this traffic is
invisible to end users-it's traffic that's part-and-parcel of data
center and cloud-computing workloads. Roughly 76% of data center
traffic will actually stay within the data center and "will be
largely generated by storage, production and development data,"
Another 7% will be generated between data centers, driven primarily
by data replication and software/system updates. The remaining 17%
will be from end users accessing clouds for Web surfing, email and
"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," commented Doug Merritt, Cisco senior vice president,
Corporate Marketing. "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
Also among the reports key predictions are:
- In 2011, North America generated the most cloud traffic (261
exabytes annually); followed by Asia Pacific; (216 exabytes
annually); and Western Europe (156 exabytes annually).
- In 2011, North America had the most cloud workloads (8.1
million, or 38 percent of the global cloud workloads); followed by
Asia Pacific, which had 6.7 million, or 32 percent of the global
workloads in 2011.
- In North America, traditional data center workloads will
actually decline from 2011 to 2016 (from 18.3 million in 2011 to
17.4 million in 2016), falling to a negative 1 percent CAGR.
- Global cloud traffic will account for nearly two-thirds of
total global data center traffic.
- 2014 will be the first year when the majority of workloads
shift to the cloud; 52 percent of all workloads will be processed
in the cloud versus 48 percent in the traditional IT space.
- By 2016, 62 percent or nearly two-thirds of total workloads
will be processed in the cloud.