Widespread broadband internet access has enabled service providers to offer traditionally client-based applications like word processing in the cloud. The introduction of these services has led to an increasing demand for connections with a certain level of QoE/QoS. A service with particularly high requirements is Cloud Gaming. Here the player's input is transmitted from his client to the cloud, where it is processed and the game visuals are rendered. These are then transmitted via real time video back to the player. On the one hand the video needs to be transmitted in an excellent quality and corresponding high bandwidth to provide the player with the same visual experience he would have playing the game locally. On the other hand there is also a high rate of interactivity, which causes the application to also be very delay-sensitive. This makes the service a very interesting use case for network researchers as it poses several interesting questions in different fields. This includes the identification of the key influence factors on the user perceived quality and a quantitative analysis on the system's performance and the QoE. To this end, active measurements in a Cloud Gaming testbed are conducted and real users are asked to fill a survey on the actual QoE. Analyzing and emulating different situations in the network and presenting them to the test users will provide new insights into this topic. In addition to these tests, a study on the scalability and the business potential can be investigated in various scenarios by means of simulations or theoretical models.