Foreword

In their opening sentences, the authors of this book, Madhavi W. Chandra and Stefan Rabb, span a gap in time of a few years and a few light-years. In 1943, the chief executive officer of what is now one of the world's largest information technology and computer manufacturing firms said, "I think there is a world market for maybe five computers." Twelve years later, the editor-in-charge of business books for Prentice Hall said: "I can assure you that data processing is a fad that won't last out the year." In 1990, I didn't normally tell people what I did for a living, because outside of a few geeks they had no idea what I was talking about. In 2000, I rhetorically asked a young coed whether she knew what the Internet was; she rolled her eyes and replied "that is SO condescending...."

For me, the Internet is all about mobility. Mobility means many things, though. I am mobileat this instant, I am sitting in a hotel in Tokyo, talking on the telephone with people in Washington and Kabul, and preparing an email to a person from India who lives in North Carolina which I will send via a server in California. My computer is mobileit moves around with me, and it is sometimes attached (with or without a wire) and sometimes not. In addition, we are finding ways to build networks that move as well.

The value of IP Mobility, the subject of this book, is for a fairly special aspect of this motion. If I connect from wherever I am, it is generally sufficient for me to be what Madhavi calls "nomadic"to connect from where I am using a random IP address to a server. But if I need an address that someone else can predict (perhaps for Voice over IP, for a video exchange, or to use peer-to-peer software to exchange files of interest) then the address must follow me around as I wander through the fixed Internet. IP Mobility provides the ability not only for me to connect to the world at large but for it to find and connect to me.

Today, I'm told, Internet technology undergirds perhaps ten percent of the industrialized world. It is replacing traditional telephone technology as the way one carries voice or video, and mobile telephone technology is impacting the Internet as well, as service providers seek to use common infrastructure to support fixed telephony, wireless telephony, and various forms of Internet technology.

The philosopher Hegel, Karl Marx's teacher, propounded a concept he called the "Dialectic." He observed that societies developed technology and economic systems to support themselves; agrarian societies thought in terms of land ownership, while societies built on flocks and herds thought more in terms of temporary use of land that was otherwise not owned by anyone or considered a commons. When they needed to live close together, these systems would come into conflict, and a new system would emerge built on part of each of the older systems while also offering something new. He called the original systems the "thesis" and "antithesis," and the result the "synthesis."

I think this process is at work in global communications today. There is nothing wrong with the traditional telephone system, if you want to sit at your desk. But mobile telephony, Internet telephony, and Internet data exchange are very different, and they increasingly live together. We have seen the conflicts, and we are now seeing the synthesis of a new system of which, at this point, we can only guess the form. IP Mobility, along with other technologies, will have a place in that synthesis, but it remains to be seen exactly what or how.

I'll let Mahdavi and Stefan explain the part we have worked out to date and join them in working out the next steps.

Fred Baker
Cisco Fellow
Cisco Systems, Inc.
April  2005