But the credit union decided not to go live with the hot site because of the widespread failure of voice and data networks in the Gulf Coast region. "Without the communications leg of it, no matter which data center we worked out of, we were going to be dead in the water," Mayo said.

As a result, Keesler is installing satellite communications links as network backups at its 12 locations in the U.S. and three offices in the U.K., he said. The installations have been completed at three facilities, and the remainder are due to be finished by June 1. By that date, the credit union also expects to have finished deploying a converged voice and data network that will replace an aging Cisco data backbone and a private branch exchange phone system. The converged network, which was expedited after Katrina, will be able to work over the satellite links, Mayo said.

The day after Katrina struck, Neal Hennegan, director of technology at insurer Gilsbar Inc., had to drive 60 miles from his office in Covington, La., to find a working phone so he could declare a disaster and authorize hot-site operator SunGard Data Systems Inc. to switch his IT operations to a Chicago data center.

Like many IT managers who experienced the storm and its aftermath, Hennegan can quickly list the things he did right and the things he has since addressed. For instance, he was especially pleased that Gilsbar had tested its SunGard backup capabilities before Katrina struck, because that helped avoid start-up delays at the hot site. But Hennegan said he plans to send IT employees to Chicago in advance of any future storms "and empower them to declare a disaster without talking to us."

Even at a company like Blue Cross and Blue Shield of Louisiana, which had invested heavily in business continuity capabilities, Katrina managed to expose issues. For instance, the health insurer used diverse routing techniques on its networks but wasn't aware that at one point they all went to a common physical site in New Orleans, Mehaffey said.