was very little cooperation between CCITT (now ITU-T) and ISO/IEC management groups. After the publication of M.30, the collaborations between these groups improved and many of the OSI ideas were incorporated into TMN. At the end of this chapter you will have a good understanding of OSI network management models and how it compares with TMN. 5.1 Introduction The OSI network management architecture mainly consists of four models. They are: Organization model Information model Communication model Functional model The OSI organizational model, also called OSI system management overview, was defined by ISO-10040. It defines the components of the network management Fundamentals of EMS, NMS and OSS/BSS system, the functions and relations exhibited by these components that make up the network management system. The OSI information model defines how management information is handled in ISO-10165. It details the structure of management information with SMI (struc- ture of management information) and storage of information with MIB (manage- ment information base). The OSI communication model defines how management information is exchanged between entities in the network management system. The transport medium, message format, and content are also discussed. The OSI functional model defines the functions performed by the network management system. The capabilities of the network management system are clas- sified into a set of basic functions, with the capabilities being derived from these basic functions. OSI network management concepts had a major influence in telecom manage- ment. Most of them form the basic principles of telecom management including the agent-manager framework that is used for data collection from elements. The object- oriented approach in OSI network management was appealing for managing the complex telecom network. The CMIP (common management information protocol), an application layer protocol, was developed based on OSI guidelines and is discussed later in this book. Though CMIP is not as popular as