This book attempts to define many of the terms/acronyms, etc you encounter in daily life working in the internet and telcom world. Unfortunatly, there are so many errors in this book that it makes it useless at best, and mideducational at worst. In 10 minutes of flipping through pages, I counted atleast a dozen errors, and that was enough to put any information presented in this volume into a questionable state.Examples, according to the book: A T1 is also known as a DS0 An OC3 has 255 Megabits of bandwidth, and an OC192 is 3 OCs.I was hoping for a handy desktop reference and got oh so much less.