Figure 1
The diagram shows a layered software-defined networking architecture arranged from top to bottom with three horizontal sections labeled “Application Layer”, “Control Layer”, and “Infrastructure Layer”. At the top under “Application Layer”, a rounded rectangular container labeled “A P P S” contains four smaller rectangular boxes labeled “Traffic Engineering”, “Load Balancing”, “Security”, and “Network Monitoring”, followed by an ellipsis showing additional applications. Between the application layer and the middle layer, three vertical double-headed arrows point downward and upward, and the label “Northbound A P I” appears to the right of these arrows. In the middle section labeled “Control Layer”, a large rounded rectangle contains the text “S D N Controller” centered inside. Below this, three vertical double-headed arrows connect the control layer to the bottom section, with the label “Southbound A P I” positioned to the right of these arrows. In the bottom section labeled “Infrastructure Layer”, a long rounded rectangle contains four device icons arranged from left to right: a circular router icon labeled “Router”, a rectangular network device labeled “Switch”, a smaller rectangular device labeled “Hub”, and a desktop computer icon labeled “P C”, followed by an ellipsis showing additional devices.SDN architecture. Source: Created by the authors