This illustration uses a series of boxes to depict the architecture of a router. At the top of this image we see a text box labeled "Routing processor." Below this box is a dashed line; the area above the line is designated as "Routing, management control plane (software)," and the area below the line is designated as "Forwarding data plane (hardware)." Below the line are two rows of boxes: three on left and three on the right in each row, with a single large box in the middle. The three boxes on the left, in both rows, are labeled "Input port," while the three boxes on the right, in both rows, are labeled "Output port." The large box in the middle is labeled "Switch fabric." Data packets go from left to right, through each of the three input ports, through the switch fabric, and through the output ports. A dashed blue line extends out from the routing processor to the left, then vertically downward through the third input port in the top row and the third input port in the bottom row. Three blue dots link the middle input ports in the top and bottom rows, and the middle output ports in the top and bottom rows.