Cloud Traffic Hits Data Center Tipping Point, Cisco Study Finds

Cloud computing now makes up the majority of data center traffic, and it’s growing steadily.

Traditional private data center generated 827 exabytes (EB) of data traffic in 2015. Cisco forecasts traditional data center traffic to grow marginally, up to 1.2 zettabytes (ZB) by 2020.

Cisco is forecasting 14.1 ZB of cloud data center traffic in 2020, representing 92 percent of all data center traffic.

The public cloud in 2015 represented 49 percent of all cloud data center workloads. In contrast, by 2020, public cloud will outpace private cloud, with 68 percent of workloads running in the public cloud. Cisco is forecasting a 26 percent CAGR for public cloud data center workloads from 2015 to 2020.

Hyperscale data centers that help to enable large public clouds and popular social network providers are set to grow, according to Cisco. 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 data centers will represent 53 percent of all traffic and 47 percent of total data center-installed servers.

While data centers connect to the outside world, the majority (77 percent) of data traffic stays within the data center, with only 14 percent going from the data center to the user, the report found.

Workload density is a measurement that looks at the number of workloads per physical server. For traditional, non-cloud data centers, workload density in 2015 was 2.2; in contrast, for cloud data centers, 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.

A key challenge with scaling up data centers is how to deal with networking, which is where software-defined networking (SDN) and network functions virtualization (NFV) can play a role. Cisco said in 2015, 23 percent of data center traffic was supported by SDN and NFV platforms. In contrast, by 2020 the forecast is for SDN and NFV to support 44 percent of data center traffic across all types of data centers.