Congestion control is a fundamental corner stone of networks and it is still part of active research. To evaluate and test new or adapted congestion control algorithms, researches usually resort to simulations. However, while popular network simulators like Ns3 are good at simulating the network itself, they lack, for example, a detailed simulation of the hosts. The hosts are typically simulated only in a high-level behavioral manner, which may neglect certain behaviors, e.g. caching behavior. In this sense, network simulators do not provide detailed end-to-end simulations. Using SimBricks we can overcome these limitations by combining multiple simulators into detailed end-to-end simulations (e.g. simulating the network with Ns3 and the hosts with Gem5). This project aims to create a testbed that makes it easy to build, configure and run congestion control experiments in SimBricks. Furthermore, we want to investigate whether (and in which cases) detailed end-to-end simulations in SimBricks achieve better/more realistic results than pure Ns3 simulations.