A Novel Scheme for Preventing Out-of-Order Packets in Fast Handover for Proxy Mobile IPv6

Fast handover for Proxy Mobile IPv6 (FPMIPv6), a protocol described in RFC 5949, is used to resolve handover latency and packet loss problems that occur in the Proxy Mobile IPv6 (PMIPv6) protocol. However, while implementing the FPMIPv6 scheme in the testbed, we reveal the Out-of-Order Packet (OoOP) problem. We propose a new scheme using last packet marker and buffering to handle the OoOP problem in FPMIPv6, since the problem significantly affects QoS of the network and performance of the Mobile Node (MN). The cause of this problem is the existence of two paths for data transmitted from Correspondent Node (CN) to MN in FPMIPv6. The new Mobility Access Gateway (MAG) can control and deliver the data transmitted via the old path or the new path to MN in chronological order, using the last packet marker to notify the end of data delivery in the old path and the buffering for holding the data delivered in the new path. We implement both the proposed and FPMIPv6 schemes in a testbed as a real network environment to demonstrate the correctness, cost effectiveness, and performance of the proposed scheme. Performance evaluation reveals the proposed scheme can handle the OoOP problem efficiently.