Web traffic volumes will almost double every two years from 2007 to 2012, driven by video and web 2.0 applications, according to a report from Cisco Systems.

Increased use of video and social networking has created what Cisco calls 'visual networking', which is raising traffic volumes at a compound annual growth rate of 46 per cent.

Cisco's Visual Networking Index (PDF) predicts that visual networking will account for 90 per cent of the traffic coursing through the world's IP networks by 2012.

The upward trend is not only driven by consumer demand for YouTube clips and IPTV, according to the report, as business use of video conferencing will grow at 35 per cent CAGR over the same period.

Cisco reckons that traffic volumes will be measured in exabytes (one billion gigabytes) by 2012 and will reach 552 exabytes by that time.

Soon after 2012 we will have to adopt zettabytes (one thousand billion gigabytes) to express traffic volumes.

The report is based on Cisco's own predictions and aggregates analysis from several market research firms.