Through the activities of MPEG (Moving Picture Experts Group), a number of issues have been identified within the scope of IPMP (Intellectual Property Management and Protection). This paper aims to address parts of them in the aspects of overall structure of MPEG-21 IPMP and to result in increasing the understanding of MPEG standardization works. In particular, this paper will address the major issues such as hooks, interoperability, and authentication architecture. Based on the architectures, this paper will explain how the MPEG-21 IPMP works with its components.