Verizon: Reconnecting - ' Lesson 3'

Lesson 3: More Eggs, More Baskets

Prior to the attacks, 140 West supplied phone service to about 14,000 business and 20,000 residential customers in Lower Manhattan. In redesigning its Lower Manhattan network, Verizon moved as many of those residential lines as possible out of 140 West, says William Hummel, Verizon's director of business recovery and continuity services. For example, lines from Battery Park City, a mostly residential development, were rerouted to one of the smaller switching facilities.

Verizon also lowered the call volume at 140 West by changing the way it routes some voice traffic. Before the attacks, calls from Lower Manhattan to New Jersey were sent through 140 West. Now, more of those calls travel through a less busy central office in midtown Manhattan.

The company says it is extending the "de-hubbing" project to some other high-volume central offices. Still, there are limits to how much traffic Verizon can offload. For the most part, lines to financial firms in the Wall Street area still have to terminate at 140 West. Even with the de-hubbing, 140 West will handle more than 90% of the data traffic volume that passed through the facility before the 9/11 attacks.

Verizon is counting on redundant cables and the optical rings to keep data moving if a network failure occurs.