The backbone network – so called because it forms a principal data route between cities – can transmit data at 1.2 terabits (1,200 gigabits) per second between Beijing in the north, central China’s Wuhan and Guangzhou in the southern province of Guangdong.

The line, which spans more than 3,000km (1,860 miles) of optical fibre cabling, was activated in July and officially launched on Monday, after performing reliably and passing all operational tests.”