英文资料，绝对经典 1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Protocol Overview . . . . . . . . . . . . . . . . . . . . . . 3 3. The Service Interface for Requesting IP Multicast Reception . 9 4. Multicast Listening State Maintained by Nodes . . . . . . . . 11