Today, the optical Fiber is widely used in France, Europe and in the world. In France and Europe, we can mention the network that LDCOM comprises 11,000 km of fiber connecting 60 cities. By using WDM and SDH, it and can reach speeds of several hundreds of Gbit / s. Extended ends by MAN, the network now extends Spain, Italy and Switzerland. At the global level, the intercontinental routes are in