This paper presents an overview of the implementation of Application Layer Multicast (ALM) in OverSim, a simulation framework designed specifically for simulating overlay networks. OverSim builds upon the OMNeT++ discrete event simulator. In addition, the paper presents guidelines for further research work based on reliable and Quality of Service (QoS)-aware multicast overlay networks. This research work is part of a bigger research project, called "Routing in Overlay Networks (ROVER)" which is focused on unicast and multicast routing in overlay networks with QoS guarantees and congestion control facilities on top of existing and future Peer-to-Peer (P2P) networks.