Implementation of a portable-IP system for mobile TCP/IP

In the current TCP/IP-based systems, the hardness of mobile communication stems from the IP routing and addressing schemes. In this paper, we refine our mobile solution using two mappings: namely; a prtable-IP mapping and a mobile mapping. We also explicity distinguish our two mapping approach from the existing mobile-IP solutions which are of a single mapping scheme. The portable-IP mapping is supported using DHCP and DNS functions and requiring no modifications to the TCP/IP protocols. The mobile mapping is implemented in the socket layer. Our mobile solution achieves high compatibility with the current TCP/IP systems mainly because that no special functionality is required to support mobility in the network and the transport layers. In terms of performance, our mobile solution can reduce both the cost for distributing the location information of mobile hosts and the cost of forwarding IP datagrams across the Intenet. In this paper,we also focus on the implementation details of the portable-IP system for supporting the portable-IP mapping. Two registration procedures and DNS updating approaches are given. We show that using the new BIND version 8.1.1. can avoid to reload the whole DNS database frequently