A virtual home agent based route optimization for mobile IP

The basic mobile IP has a so called "triangle routing" problem, namely, all datagrams for a mobile host have to been routed first to its home agent and then forwarded by the home agent to the mobile host. Those paths are often significantly longer than optimal. Although the route optimization extensions in mobile IP can solve this problem, it requires the Internet hosts that communicate with a mobile host to be able to understand some mobility related messages. Unfortunately, that's not true for most Internet hosts. We propose a novel and simple virtual home agent based route optimization solution to this problem. It is based on two observations: a permanent home address is not really necessary for many Internet applications on a mobile host and a mobile host's mobility is highly localized during a certain period of time. By having a foreign network within a mobile host's localized footprint to be it's virtual home network, it can greatly alleviate the triangle routing problem because of the mobility locality nature, and, at the same time, enable the mobile host to communicate with any conventional Internet hosts that are not mobility aware.