AT&T kicked off a six-day network disaster recovery drill to test its backup systems and strategy in the event of a serious network problem.

 
The exercise, carried out near Seattle, is designed to see how staff and systems respond to a disaster that affects data-routing or voice-switching centres.
 
A spokesman for the telco said day one of the test was on the third anniversary of the earthquake that hit the Puget Sound area.
 
Over the past decade, AT&T says it has invested more than $300 million in its disaster recovery program