Multicast service of multimedia data messages are attractive network application. In conventional TCP/IP computer network, all functions of group membership management, routing and bandwidth reservation are required to be supported by all intermediate routers and availability of the multicast service is not always enough for network users. The overlay multicast is an expected solution where only logical configuration, i.e. routing in a logical network, is required and is supported by computers engaged to the multicast service. However, for support multimedia data transmission, bandwidth reservation in physical communication links is required and cooperation of overlay network layer and physical network layer is required. This paper proposes a novel bandwidth reservation method for overlay multicast where bandwidth are correctly reserved even if multiple logical communication links share a physical communication link.