y separate network operated by other providers. Signals, or the absence of signals between the OTN equipment on the fiber and the Network Opera- tions Center (NOC), triggers software commands that automatically re-route traffic. Some carriers might prefer the option to have engineers manually activate alternative routing during outages. Mesh technology ensures that the many organizations and consumers who depend on core fiber networks have uninterrupted service during outages. When the glitch is repaired, traffic is automatically directed back to the original network route. Mesh technology is a critical tool during national disasters. It has the capability to provide alternate routing for both wireless and wireline networks. During hurricanes, instance, traffic in the affected area of the carrier's network can be rerouted to other sections of the provider's network, or to other carriers altogether, depending on logis- tics and agreements between carriers. Mesh technology assumes adequate capacity on backup routes. If this capacity is not sufficient, delays will occur. It's a trade-off between flexibility in having multiple backups, idle capacity when the network is operational, cost savings, and possible congestion during emergencies. Using Mesh Configuration to Back Up Undersea Cable Service The reliability of undersea cables is critical, because entire countries or metropolitan areas often depend on a single undersea cable for international service. Due to the com- plexity of repairing cabling systems on the ocean floor, major outages can put regions or countries out of contact with the rest of the world for a week at a time. Beginning in 2003, carriers started using mesh technologies as a backup service for undersea cables. Prior to that, only costly ring topologies were viable, though at least half sat idle unless there was an outage. New undersea cabling systems use mesh technology and opera- tors make arrangements with other carriers for backup on other undersea systems. Providers often have agreements for 