In this thesis I will present the Carrier Ethernet network and its application on aggregation networks. I will demonstrate it in two steps, using two different models. First, I will demonstrate the properties of a Carrier Ethernet network, and then I will specify the ring-based CET aggregation network. After that I will show the steps of the method which helps to design a network based on ring topology. To invent the topological realization of this network I will use a linear programming model and I will present a few examples which will show that the result is correct. The other presented model is a tree based model and its technical design, which will be demonstrated in a more detailed version. Initially I will show how to find a shortest path between to vertexes, and then I will use the Steiner tree problem to define the minimum spanning tree in a graph. During the planning I will follow the steps of the implementation of the ring-based model and the same linear programming approach. My goal is to realize these two different networks and to present the differences between them from engineering and economical perspectives.