The proportion of real-time traffic, being transported over IP networks, appears to be ever increasing. Real-time traffic may, for example, consist of video and audio data, which have real-time constraints in terms of metrics such as maximum delay, delay jitter and packet loss. Bounds on such metrics can be hard to satisfy by the network, hence there is an incentive to make multicast streaming of video more packet-loss resilient. Receiver-driven layered multicast has been proposed for dealing with band limitations, and environments with heterogeneous terminals. We have extended these ideas to handle packet loss, by adding receiver-driven forward error control (FEC). The aim of this paper is to further improve the performance, by optimizing the distribution of the error protection between the layers.