 need to support network elements from multiple vendors each having their own proprietary protocols for management. Standardized management protocols were introduced that defined a common vocabulary that could be used for communication. Fundamentals of EMS, NMS and OSS/BSS There is no ideal standardized management protocol suited for all kinds of net- work elements and management applications. The management protocol suited for web-based network management may not be best suited for a client-server appli- cation and the management protocol for a packet-based network may not be best suited for a circuit switched telecom network. Hence various standardizing bodies worked on developing management protocols for various management applications and networks. These efforts and resources have resulted in a vast choice of standard- ized protocols, with vendors offering a wide range of tools and platforms based on these protocols. These tools and platforms greatly facilitate the development and integration of the management systems and network elements. Application and network are not the only items that determine the choice of a management protocol. It can also be a trade off between complexity and simplicity. Some protocols are aimed at simplicity, which would ensure easy agent implemen- tation and short turn around time in software development. These protocols like SNMP (simple network management protocol) are better structured and easy to understand. The simplicity in interaction often results in extra functionality to be inserted in mapping of the information model. There are protocols like CMIP (common management information protocol) that are more functionality rich and have an object-oriented structure making it a complex protocol. The wide range of operations in the protocol results in com- plex but powerful agents. There can also be scenarios where different management protocols should be combined within the same network element yielding the best solution for a specific interaction paradigm. This chapter gives an