NGN is a communication network which can make use of multiple broadband and QoS-enabled transport technologies. One of the main service issues over NGN is a multimedia service, like IPTV and VOD, which is using multicast technology. And overlay multicast technology is one of the promising solutions instead of general multicast technology which has a few problems, and supports flexibility and scalability for multicast services. Also, the main controversial topic in NGN and overlay multicast at present is QoS.In the present paper, we designed an agent in each receiver’s network and a manager which is in a source network and which manages the whole multicast network. Both of them are communicating with each other and applying resource policies to their multicast network. This mechanism enables overlay multicast to support QoS, focusing on RACF in NGN architecture.