In recent years, inexpensive and lightweight portable terminals such as laptop PCs are spreading, and outdoor Internet services such as wireless hot spots are increasing. Therefore, users can connect to the Internet at various locations by their own terminal. However, if a terminal establishing TCP connections starts to move to another network, there is a problem that TCP connections are aborted due to retransmission timeout and the change of terminal's IP address. In this paper, we propose a method to preserve TCP connections for macro mobility of terminals by hiding the change of IP address from TCP layer using VPN and by preventing retransmission using proxies.
