Core Layer: The core layer is the backbone of the hierarchy network. The primary transmission and routing of data signals take place at the core layer only. It is a powerful backbone switch in the center of the network core layer, which centralizes multiple aggregation switches to the core and implements LAN routing. The strategic design of a hierarchy network may comprise more than three layers. A core switch is a high-capacity, high-performance Layer 3 switch positioned at the physical backbone of an enterprise network.