Introduction

The Internet and mobile communications are defining how and when people access information, with mobile phones, PDAs, and laptops driving the need for "always-on" IP connectivity. One challenge to mobile data communication is moving data across different networks while maintaining communication. The solution to this problem is a standards-based protocol: Mobile IP. Mobile IP is an open standard defined by the IETF that allows users to keep the same IP address, stay connected, and maintain ongoing applications while roaming among IP networks.