backup on more than one route. This affords more options during disasters such as earthquakes that can affect multiple cables to the same country. If no viable undersea cable on the same route is available, traffic is routed overland to the nearest distant city with an alternate undersea cable. Convergence in Core and Metropolitan Networks Repairing undersea cable cuts requires the costly deployment of submersible robots tethered to and controlled by mother ships. Large trawling fishing nets responsible for the most fiber cuts. These nets are weighted and often snag cabling as they are being dragged across ocean floors. The second most frequent cause of out- ages results from ship anchors dragged across the ocean floor. To reduce the incidence of costly cable cuts from fishnets and ship anchors, cable companies provide maps of their cable routes to fishing companies. Using ROADMs to Add and Drop Off Traffic Using Reconfigurable Optical Add/Drop Multiplexers (ROADMs), carriers can more easily add, separate out, and drop off traffic carried on optical rings to and from other providers and to other network sites without converting signals to electrical signals and back to light signals. Prior to the availability of ROADMs, light signals had to be converted to electrical signals before they could be added or dropped off and routed elsewhere. ROADM equipment eliminates the extra cost and maintenance for this con- version equipment. ROADMs were first deployed in core networks SO that, for example, some of the traffic between cities such as New York and Chicago could be more easily routed to Los Angeles. As traffic within metropolitan areas increased, ROADMs began to be used in these areas as well. Dense Wavelength-Division Multiplexers (DWDMs) can be equipped with ROADM cards SO that fewer pieces of gear need to be maintained. Transitioning Broadband Customers to Voice over Internet Protocol Local telephone companies use legacy local Class 5 switches to provide service to customers who are still using analog telephones