In this paper, on the basis of end-to-end principle, we propose a mobility management scheme to solve the NAT issue. Furthermore, since different communication technologies own different characteristics, during a vertical handoff, a well-behaved mobility management system should adapt an ongoing connection to different communication systems. In this paper, we also propose a handoff-aware TCP adaptation scheme, called CWND-restore. To verify the feasibility of our approach, we implement a prototype system on Linux. The experimental results show that our mobility management scheme can work under various mobility cases. Furthermore, our proposed CWND-restore scheme can offer higher TCP throughput during a vertical handoff. For example, the TCP throughput by proposed adaptation scheme is at most 2.3 times the original TCP