Extending TCP retransmission timeout at mobile IP handoffs for Windows 2000: a case study

Current mobile IP mechanisms put much emphasis on smoothly roaming around networks based on the performance consideration. However, chances are that the user leaves a network attachment too long to resume the original connection because of retransmission timeout in transmission control protocol (TCP). Against this situation, we justify the connectivity preservation by sacrificing a little performance due to TCP´s congestion control at handoffs in mobile IP and propose a mechanism to extend the deadline of retransmission timeout. After implementation and test, it shows that the time is extended near four times than the unapplied one at Windows 2000 operating system. While the mobile host loses contact with the network attachment, our mechanism can give the connection more chances to survive than mobile IP.