Cisco published its sixth annual Global Cloud Index report on November 10, providing a forecast into how cloud is set to evolve in the period from 2015-2020. The big top-line highlight for the report is that Cisco is now forecasting that by 2020, cloud traffic will represent 92 percent of all data center network traffic.
In 2015, Cisco's estimates that 3.9 zettabytes (ZB) of cloud traffic transited data centers, accounting for approximately 75 percent of data center traffic. by 2020, Cisco expect data center traffic to grow to 14.1 ZB per year, with cloud representing 92 percent of the traffic. The five-year Compound Annual Growth Rate (CAGR) for cloud traffic is approximately 21 percent.
Cloud traffic is also leading to an increase in the number of workloads per physical server, which Cisco categorizes as 'workload density'. For traditional, non-cloud data centers, workload density in 2015 was 2.2, in contrast, cloud data center workload density was 7.3. Looking forward, by 2020, Cisco forecasts that workload density in traditional data centers will grow to 3.5, while cloud data center workload density will grow to 11.9.
Additionally, Cisco expect that the public cloud will grow faster than private cloud over the next four years. CAGR for public cloud growth is forecast at 35 percent while private cloud growth is forecast at a CAGR of 15 percent. By 2020, Cisco forecasts that 68 percent of all cloud workloads will be in the public cloud, with the remaining 32 percent in private cloud deployments.
"In the six years of this study, cloud computing has advanced from an emerging technology to an essential scalable and flexible part of architecture for service providers of all types around the globe," said Doug Webster, Vice President of Service Provider Marketing at Cisco, said in a statement.
A core element of enabling the continued growth of cloud data center traffic are Software Defined Networking (SDN) and Network Function Virtualization (NFV), approaches that help operators to scale rapidly. In 2015, Cisco said that 23 percent of data center traffic was supported by SDN and NFV platforms. By 2020 the forecast is for SDN and NFV to support 44 percent of data center traffic across all types of data centers.
Cisco's report also examines the phenomena of what it refers to as 'hyperscale' data center. There are the data center types that support large public cloud and popular social network providers. In 2015, there were 259 hyperscale data centers and Cisco forecasts that number to grow to 485 by 2020. By Cisco's estimates, by 2020, hyperscale datacenters will represent 53 percent of all traffic and 47 percent of total data center installed servers.
Perhaps the largest single growth metric over Cisco's forecast period is for data center storage capacity, which is set to expand five-fold. In 2015, Cisco pegs data center installed capacity at 382 exabytes and expects it grow to a whopping 1.8 Zettabytes by 2020.
Sean Michael Kerner is a senior editor at EnterpriseNetworkingPlanet and InternetNews.com. Follow him on Twitter @TechJournalist