Tunnel Restraint to Prevent Out-of-Order Packets for Route Optimization in Proxy Mobile IPv6

Abstract

Route optimization (RO) developed for Proxy Mobile IPv6 (PMIPv6) aims at reducing the packet transmission cost. However, as we present in this paper, the RO procedure may cause out-of-order packets. In this paper, we propose a tunnel restraint scheme to minimize out-of-order packets during a mobile node (MN)'s handover by utilizing a developed estimation function that calculates an amount of out-of-order packets in the RO procedure. In the proposed tunnel restraint scheme, buffering techniques at proxy mobility agents are adopted to minimize the arrival of out-of-order packets to the MN. The proxy mobility agents taking part in the RO procedure buffer the packets for the MN until they establish the RO tunnel between them. The conducted performance evaluation results show that the traffic rate and the time period of out-of-order packets mainly have effects on the out-of-order packets problem. We also demonstrate that the proposed tunnel restraint scheme enhances the performance of PMIPv6 RO by minimizing the number of out-of-order packets.