Technical building infrastructure systems are developing towards the IP protocol. Now for the first time, lighting, an area hitherto the reserve of the classical electrical engineering, is becoming fully integrated into the IP network. This is made possible through the use of LEDs with their low voltage and low currents. However, to make the most of the technical and economic advantages offered by LED lighting solutions, a powerful infrastructure with intelligent network switches is needed. Applications (apps) on the switches allow extensive functionalities and thus make a significant contribution to the Smart Building.