I took a course in queuing theory using this book (graduate level). The first few chapters of the book are alright but after that the author throws in undefined variables and skips dozens of steps. It reminds me of looking over someones shoulder as they mumble to themselves and I'm trying to figure out what their doing or what steps they are taking. I have no idea how this book got so many good reviews! I'm guessing that they are from professors who already know queuing theory and probably don't need the book anyways. Add on to that my professor did not teach the class but expected the grad students to teach it to each other. It was a nightmare. "excercises" in the book take hours to do even for someone familiar with the field and at the end you have no idea if you've done it right or wrong. - no solutions manual for steps. RUN FROM THIS BOOK