Mobile IPv6 (MIPv6) is designed to support mobility in IPv6 networks. Although Hierarchical MIPv6 (HMIPv6) is supposed to enhance the performance of MIPv6 by hierarchizing the network, it cannot always outperform MIPv6. These, two solutions have different application scopes. In this paper, a model is implemented to analyze the application scopes of MIPv6 and HMIPv6, through which an Optimal Choice of Mobility Management (OCMM) scheme is designed.