The use of optic fiber and laser technology ensures that connections can be made over very long distances (e.g. more than 100 km (60 miles) between 2 nodes, network size >2000km (1200 miles)) with excellent transmission quality.
To improve the reliability of the fiber optic backbone, a redundant fiber optic ring topology is used. This allows the OTN (Optical Transport Network) to restore itself automatically in case of an optical fiber cable break. Multiple of these redundant OTN (Optical Transport Network) rings can be coupled to provide the optimal network topology.