The convergence of future fixed and wireless networking more and more requires solutions for transporting realtime application data to IP enabled mobile devices and mobile networks. Even if the general Mobile IPv6 protocol performs sufficient in macro environments with non-realtime requirements, seamless mobility demands some more enhanced protocol procedures in between the mobile client and the involved network entities. Limiting the effect of handovers has the potential to considerably improve handover performance in terms of latency and packet loss. This contribution is going to present simulative studies on the performance of a future 4G Hierarchical Mobility Management approach. The demonstrated simulation scenarios comprises 3 independent access domains, twelve access routers, and up to 72 mobile clients that communicate in accordance with the popular IEEE 802.11 wireless LAN standard, as one of the possible wireless access networks in a future All-IP network infrastructure.