The Low Tech Idea Behind High Tech Mobile IP

With Mobile IP, even if you are halfway around the world from your regular workstation, any network will recognize your computer or your palm pilot as unique. This has a major impact on important issues like the security of wireless networks, and on less important issues like who is allowed to enter a web chat room. Your computer's IP address is its secret knock on the closed doors of the internet, and Mobile IP technology allows that knock to be heard.

Mobile IP makes it possible for your wireless device to retain its own distinct IP address and identity no matter where you take it or what network it is connected to. Every device that has wireless capability, like a laptop or a BlackBerry, has its own permanent IP address. This address serves like a unique name that distinguishes your computer or PDA from any other device of its type. Without the set of communication protocols known as Mobile IP, however, your device's permanent IP address would become all but useless because it would not be fixed.

Mobile IP is essentially a high tech version of the very simple idea of having the post office forward your mail to your vacation address. The way that Mobile IP protocol works is by allowing devices to have IP addresses that aren't related to their point of network entry. A device, or "node," can take on a temporary IP from the network it is using in addition to its permanent IP. When another node wants to get information to your node, it won't actually try to send anything to your mobile device. Instead, it will send the data to your device's permanent IP at your device's home base. That data gets intercepted and sent to the "care of" address associated with the network your mobile node is connected to, thereby getting to your device.