MCI Communications Corp., Washington, DC, has installed Synchronous Optical Network (Sonet) rings in Cincinnati, Dallas, Detroit and Seattle. The Sonet deployments include a meshed ring topology for maintaining and rerouting connections in case of line failure. MCI also completed an upgrade of its Internet backbone to 155 megabits per second.
Sprint Corp. runs 75% of its telecommunications traffic via Sonet; its backbone is scheduled to run entirely on Sonet by year`s end. Ameritech currently offers Sonet capabilities in most major cities in its region, while BellSouth provides Sonet services in Florida. BellSouth and Lucent Technologies have also instituted a Sonet network for the 1996 Olympic Games in Atlanta.
US West is deploying Sonet in seven major metropolitan areas in its operating region. It has completed a ring around Phoenix, and a Seattle ring is expected shortly; a ring around Minneapolis is planned by year`s end. GTE, another competitor, supports 135 Sonet rings in 19 states throughout the U.S. and expects to have 275 Sonet rings completed by the end of 1998.