Telecommunication is currently a highly expanding market. New technology offers much more flexibility to the provider of services, but also confronts him with new problems. In this talk several of these problems are addressed. They all center around the question of how to impose "optimal" structure on a telecommunication network. Since there are conflicting interests, such an optimal structure is quite difficult to identify. We present results on how to partition a given network into many small subnetworks such that the total traffic between the subnets is minimized. We close with computational experience on real world data from France Telecom.