Global data centre traffic will grow fourfold to reach a total of 6.6 zettabytes annually by 2016, Cisco Systems Inc. forecasted in a report released Tuesday. The report, called the Cisco Global Cloud index, said cloud traffic will be the fastest-growing segment of data centre traffic, growing by a factor of six by 2016. Cisco said in a release that 6.6 zettabytes of data is equivalent to about one and a half years of continuous music streams by everyone on the planet in 2016. For the period 2011-2016, Cisco forecasted that about 76 per cent of data centre traffic will stay within data centres and will be largely generated by storage, production and development data. Another seven per cent of data centre traffic will be generated between data centers and primarily driven by data replication and software and system updates. The remaining 17 per cent of data centre traffic will be end users accessing the clouds through Internet usage, messaging and video streaming, Cisco said. Cisco said that, through 2016, the Middle East and Africa will experience the largest growth in traffic. The Asia Pacific region will process the most cloud workloads during the period, the report said, followed by North America. The index is generated by modelling and analysis of primary and secondary sources, including 40 terabytes of traffic data sampled from global data centres over the past year, as well as data from more than 90 million network tests conducted over the past two years, the release said.