Mobile IP use of private addresses in an RSIP home network

Use of private addresses in a mobile node´s home network brings a challenge to mobile IP because a private address cannot uniquely identify the mobile node in the public network. Here we present an approach that a mobile node whose private home network is isolated from the public network by a realm specific IP (RSIP) gateway can communicate with a correspondent node when the mobile node visits the public network. Our solution neither uses any private addresses in the public network nor brings any additional security issues. In this paper, our methods are explained, and detailed procedures as well as packet formats are illustrated