The mobile user population connected to the Internet continues to grow in number and hence provisioning seamless Internet service to such user is a topic of major interest. With new mobility architectures being investigated, it is important to have consistent comparative platforms and metrics. In this paper, the authors introduce a novel and user-centric handoff cost framework to analyze handoff performance of different mobility schemes. The proposed framework helps examine the impacts of registration costs, signaling overhead, and data loss for Internet connected mobile users employing a unified cost metric. They first applied the framework to their future Internet mobility architecture, called Virtual Mobility Domains (VMDs).