Most everything in our experience requires management in some form or other: our gardens, our automobiles, our minds, our bodies, our love lives, our businesses, our forests, our countries, etc. Sometimes we don't call it "management" per se. We seldom talk about managing our minds or automobiles. But if we think of management in terms of monitoring, maintaining, and cultivating with respect to some goal, then it makes sense. We certainly monitor an automobile, albeit unconsciously, to make sure that it doesn't exhibit signs of trouble. And we certainly try to cultivate our minds. This book is about managing networks. That itself is not a new concept. We've been managing the networks that support our telephones for about 100 years, and we've been managing the networks that support our computers for about 20 years. What is new (and what motivated me to write this book) is the following: (i) the enormous advancements in networking technology as we transition th st from the 20 century to the 21 century, (ii) the increasing dependence of human activities on networking technology, and (iii) the commercialization of services that depend on networking technology (e.g., email and electronic commerce).