erefore obliged to retain the CoA as the source address. In reception, the correspondent node must replace the CoA with the address HoA to reconstitute the socket. 9.1.1.3. Routing extension The Routing extension (type 2) contains the HoA of the mobile node. The Routing extension is used for the direct transfer of data from the correspondent node to the mobile node. The correspondent node transmits the packet to the CoA destination address of the mobile node. Upon receiving the packet, the mobile node replaces the CoA with the HoA of the Routing (type 2) extension to reconstruct the socket. 9.1.2. ICMPv6 messages 9.1.2.1. Message Home Agent Address Discovery Request The message Home Agent Address Discovery Request is transmitted by the mobile node to the home agent. The source address is the CoA of the mobile node. The destination address is the anycast address constructed from the HoA of the mobile node. The value of the Type field of the ICMPv6 message is 144. 9.1.2.2. Message Home Agent Address Discovery Reply The message Home Agent Address Discovery Reply is transmitted by the home agent in response to the previous message. It contains a list of HAA. The value of the Type field of the ICMPv6 message is 145. Wi-Fi Integration to the 4G Mobile Network 9.1.2.3. Message Mobile Prefix Solicitation The message Mobile Prefix Solicitation is transmitted by the mobile node to the host agent in order to update the configuration of its HoA. The source address is the CoA of the mobile node. The destination address is the HAA. The Destination extension must be inserted. The value of the Type field of the ICMPv6 message is 146. 9.1.2.4. Message Mobile Prefix Advertisement The message Mobile Prefix Advertisement is transmitted by the home agent either in response to the previous message or in an unsolicited manner. In both cases, the destination address is the CoA of the mobile node. The Routing extension (Type 2) must be inserted. The value of the ICMPv6 message type field is 147. The ICMPv6 message incorporates the Prefix