S-RO: Simple Route Optimization Scheme with NEMO Transparency

Network mobility (NEMO) basic support protocol maintains the connectivity when mobile router (MR) changes its point of attachment to the Internet by establishing a bidirectional tunnel between MR and Home Agent (HA). However, it results in pin-ball routing and multiple encapsulations especially in the nested NEMO. In order to solve these problems, we propose a simple route optimization scheme for NEMO and nested NEMO. In the proposed scheme, a correspondent node (CN) maintains network prefix binding information of intermediate MRs to obtain optimal path to the mobile network node (MNN). For a CN to receive network prefix bindings, each intermediate MR updates its network prefix binding to the inner source of the encapsulated packet, when it receives an encapsulated packet from its HA. The proposed scheme uses the routing header type 0 (RH0) and the routing header type 2 extension (RH2 extension) to deliver packets to the MNN through the optimal path and to remove multiple encapsulations. In addition, we extend the Router Alert Option (RAO) so that the MR knows the original source address of the packet, when ingress filtering is applied.