By 2015, 76 percent of data center traffic will remain within the data center itself as workloads migrate.
In its inaugural Global Cloud Index (2010–2015), Cisco estimated global cloud computing traffic will grow 12-fold from 130 exabytes to reach a total of 1.6 zettabytes annually by 2015, a 66 percent compound annual growth rate. One zettabyte is equal to a sextillion bytes or a trillion gigabytes. To put that in perspective, 1.6 zettabytes is approximately equivalent to, 22 trillion hours of streaming music, 5 trillion hours of business Web conferencing with a webcam or 1.6 trillion hours of online high-definition (HD) video streaming.
The cloud is the fastest growing component of data center traffic, which itself will grow 4-fold at a 33 percent CAGR to reach 4.8 zettabytes annually by 2015. Cloud is also estimated today to be 11 percent of data center traffic, growing to more than 33 percent of the total by 2015. Cloud is becoming a critical element for the future of IT and delivery of video and content.
The report said the vast majority of the data center traffic is not caused by users but by the data centers and clouds themselves undertaking activities that are largely non-transparent to users – like backup and replication. By 2015, 76 percent of data center traffic will remain within the data center itself as workloads migrate between various virtual machines and background tasks take place, 17 percent of the total traffic leaves the data center to be delivered to the user, while an additional 7 percent of total traffic is generated between data centers through activities such as cloud-bursting, data replication and updates.
