Flushing Mechanism for Routing Optimization in PMIPv6

In order to solve the inefficient route problem of PMIPv6, a mechanism to optimize the route between two mobile nodes within the same PMIPv6 domain has been proposed. However, this route optimization mechanism may result in the out-of-order packet delivery problem. In this draft, we propose a mechanism that can resolve the out-of- order packet delivery problem by introducing the Flush message that notifies the change of the tunnel endpoint and allows the in-order delivery of packets even in the case of the route optimization.