This is a very impressive reference.Sparing you the excessive application information, it provides the logic and call flow of numerous protocols. It contained every protocol I could think of, and then some. If you are engineering or testing/certifying anything from an ATM network, Voice over IP telephone system, Distributed Mail System or Unified Messaging System to a Packet over Sonet or GigE Infrastructure with streaming multimedia, from transmission systems to routing protocols and switch logic, this is the book for you.This reference book easily gets 5 stars, and replaces several other books with one concise and detailed volume.Hats off to you Fred, you did an outstanding job!