bile node has to send a Binding Update message to its home agent to register its CoA, it may not know the HAA. In this case, the mobile node may attempt to discover the address of a home agent by sending the message Home Agent Address Discovery Request using the anycast address corresponding to the prefix of its HoA. 172 Wi-Fi Integration to the 4G Mobile Network The host agent that receives this request message returns the message Home Agent Address Discovery Reply containing the list of HAA (Figure 9.3). The mobile node, after receiving the message Home Agent Address Discovery Reply, can then send the Binding Update message to one of the The mobile node may attempt to register at each of these addresses, in the order they appear in the message Home Agent Address Discovery Reply, until its registration is acknowledged by receiving the Binding Acknowledgment message (Figure 9.3). The home agent broadcasts the Neighbor Advertisement message to refresh the neighbor table of the hosts of the originating network, for which the HoA of the mobile node is associated with the Ethernet address of the home agent (Figure 9.3). 9.1.3.2. Data transfer The transfer of packets between the correspondent node and the mobile node takes place initially through the home agent (Figure 9.4). Packets from the correspondent node to the mobile node are intercepted by the home agent. Packet source address: CNA Packet destination address: HoA The home agent encapsulates the packets received by a new IPv6 header to transfer them to the mobile node. Tunnel source address: HAA Tunnel destination address: CoA Packet source address: CNA Packet destination address: HoA Packets from the mobile node to the correspondent node are forwarded in a tunnel to the home agent. Packet source address: HoA Packet destination address: CNA Tunnel source address: CoA Tunnel destination address: HAA S2c Tunnel Establishment The home agent deletes the tunnel and forwards the packets to the correspondent node. Packet source address: HoA Packet destination address: