 cre- ating and viewing the information structure of an AMLn model. They also define the structure of an AMLn model data base. This book is a successor to my previous book (see Muth (2001)), which describes two other views of AML: AMLs (AML, service view) and AMLp (AML, protocol view). Both these views deal with behavior specification and are applica- ble when one wants to refine an AMLn model for simulation, or for generating code directly from such a model. A brief overview of AMLs and AMLp is given in Appendix D at the end. During the time I have been struggling with this book, many people have encouraged me and given me valuable feedback. I would especially like to thank Per Dahl, Anders Eriksson, Lennart Holm, Jens Larsen, and Anders Olsson. Stockholm Thomas Muth October 2004 Contents Contents 1 Introduction to Network System Modeling Systems Modeling in General Added-Value versus Common-Value Languages 1.2.1 General 1.2.2 AMLn versus UML 1.2.3 The AMLn Process Context Contributions to AMLn 1.4 Modeling Network Systems in AMLn 1.4.1 Structures in Network System Models 1.4.1.1 Layer Structure and Node Structure 1.4.1.2 Management Plane and Managed Plane 1.4.1.3 Network Levels 1.4.2 Modeling Layer Structures 1.4.2.1 The Control-Connectivity Separation 1.4.2.2 The Actor-Agent Separation 1.4.2.3 The Actor-Resource Separation 1.4.2.4 The LSM-LPM Separation 1.4.2.5 Agent Layers 1.4.2.6 Common Agent Layers 1.4.2.7 Common Actors 1.4.3 Modeling Node Structures 1.4.4 The Boundary Between Traffic and Management Systems 1.4.5 Specifying Behavior in AMLn Models 1.4.6 The Modeling Dimensions 1.4.7 Views 2 Layer Structures 2.1 Concepts Based on the OSI RM 2.1.1 Layers and Layer Structures 2.1.2 Service Types and Layer Types Contents 2.2 Discrimination (Connectivity Layers Only) 2.2.1 Introduction 2.2.2 Discrimination in the OSI RM 2.2.3 Discrimination in the Internet 2.2.4 Discrimination by Multiple Network Addresses 2.2.5 Discrimination in Circuit-Switching Layers 2.2.6 Summary 2.3 Agents and Actors 2.3.1 Introduction 2.3