REVERSE ROUTING HEADER (RRH): RRH  uses the mechanism of source routing technique to route the packets in optimal path for the nested mobile networks, while sending the packets from MNN to CN. The Mobile Router (MR) which is connected to MNN allocates 'n' number of RRH's to the previous Mobile Router (MR) along with the tunnel header.
The last Mobile Router (MR) inserts its home address in slot 1. The destination address of the outer IPv6 header is the HA of last Mobile Router (MR), and the source address is the care-of address of last MR. When the packet arrives at previous Mobile Router (MR) the Mobile Router (MR) swaps the source address with its care-of address, and records the original source address in next slot of the RRH it is similar for all Mobile Router (MR) that is connected in nested mobile network. The packet is then tunneled to the HA of 'n'th MR. Once 'n'th MR HA receives this packet, it notices the RRH and finds the packet being tunneled from the 'n'th MR. the HA then decapsulates and forwards the packet to CN .
The HA also creates a Binding Cache for 'n'th MR, including the entries recorded in the RRH and the source address of the outer IPv6 header. This Binding Cache allows packets to the MNN to be tunneled using the RRH for the opposite direction. The RRH protocol leaves the MNN and the CN untouched and only the intermediate MRs and the HA are required with the modification. RRH protocol offers the optimal route while achieving security equivalent to the NEMO Basic Support protocol.
RECURSIVE BINDING UPDATE (RBT) : Recursive Binding Update is helpful to utilize the binding information of the MR contained in the binding cache of the CN. When the CN wants to send a packet to the Visiting Mobile Node (VMN), and if the binding is present, the CN adds a type 2 routing header to the packet. The current Mobile IPv6 draft incorporates a restriction which requires that a type 2 routing header must have only one intermediate node .
For example a recursive binding update with source routing for route optimization. We modify the type 2 routing header, in order to be able to use several intermediate nodes, so as to obtain the optimal route from the CN to the VMN by recursive searching of the binding cache. The RBU has an advantage in that it requires no changes to the existing Mobile IP specification, except for the possibility of using multiple type 2 routing headers. R-BU scheme requires minimum modification to both the Mobile IPv6 specification and the NEMO Basic Support protocol to offer the optimal path. Therefore it is easy to integrate to the current specification.
PREFIX DELEGATION FOR ROUTE OPTIMIZATION: The basic idea behind prefix delegation-based route optimization  is to let Local Mobile Node (LMN), VMN and MR to obtain CoA from the prefix of the foreign network visited by the Top Level Mobile Router (TLMR), and let the CN know the CoA. Therefore, CN can send packets to this CoA to have the packets directly...