According to the second annual Cisco (NASDAQ:CSCO) Global Cloud Index (2011-2016), global data center traffic is expected 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% CAGR - from 683 exabytes of annual traffic in 2011 to 4.3 zettabytes by 2016.