IP VPN address will not change

for advertising itself, de-tunneling packets from the Home Agent, and sending the packets to the Mobile Node. (5) Home Address: The IP address assigned to a Mobile Node in the Home Network. The IP VPN address will not change when the Mobile Node is roaming. (6) Care-of Address (CoA): The IP address which is assigned to the Foreign Agent. A Home Agent tunnels packets to Mobile Node's Care-of Address. Home Agents and Foreign Agents advertise their presence by broadcasting Agent Advertisement messages. The Mobile Node examines the Agent Advertisement messages to determine its location. If the MN is connected to its home network, it operates without mobility services. When the Mobile Node is connected to a foreign network, it registers the Care-of Address with its Home Agent. The registration process sets up necessary services to re-route packets.   When the Correspondent Node sends packets to the Mobile Node, the packets are first sent to the Home Agent. The HA encapsulates and tunnels the packets to the Foreign Agent and the FA de-tunnels the packets and sends the packets to the Mobile Node. When the Mobile Node sends packets to the Correspondent Node, the packets are first sent to the Foreign Agent. The FA directly forwards the packets to the Mobile Node. Figure 3-1 shows the operation of a Mobile IP (IPv4) connection. Figure 3-1 Mobile IPv4 Chapter 3: Mobile IP Overview  Page 22 © 2009 Chen Xu  Page 22 3.2 PROBLEMS IN MIPV4 When the Mobile Node roams in foreign networks, no  matter how close the correspondent node and the mobile node are, MIPv4 forces all packets from the Correspondent Node to be routed to the Home Agent and then to be  routed to the Mobile Node. However, packets from the Mobile Node can be routed to the Correspondent Node through the Foreign Agent directly. This mechanism has poor packet routing performance and is labelled "Triangular Routing" [82] which is depicted in Figure 3-1. The word "Triangular Routing" is routing which causes sending packets to a proxy system before sending to the intended destination. Both Mobile IP and Skype have this problem.