below can be downloaded from WWW. tmforum.org 1. TMF 513, Multi-Technology Network Management Business Agreement. 2. TMF 608, Multi-Technology Network Management Information Agreement. 3. TMF 814, Multi-Technology Network Management CORBA Solution Set. 4. TMF 814A, Multi-Technology Network Management Implementation Statement (IS) Templates and Guidelines. NETWORK MANAGEMENT SYSTEM (NMS) Chapter 9 Communication Networks This chapter is intended to provide the reader with a basic understanding of com- munication networks. At the end of this chapter the reader will be able to work on the management of most communication networks by correlating components and functions with the networks discussed in this chapter. This helps in management data presentation, processing, and defining the management functionalities that will be useful when working on a specific network. 9.1 Introduction A network is a collection of elements (equipments) that work together to offer a service or set of services. For example, the telephone service where you can call your friend's mobile from your phone is not a direct one to one interaction between two user equipments (elements). The call establishment, maintaining the conversation line, and termination of call in a telephone service is made possible using a mediator network like UMTS or CDMA that has a set of elements dedicated to perform a specific function and interoperate with other elements in the network to realize the call handling service. The main operation of elements in a communication network is transmission of information (voice, data, media, etc.), where the information is transformed or evaluated to make communication between two equipments possible. Example of "Transformation" is a protocol gateway where the language for information exchange is changed from one protocol to another. "Evaluation" can happen at a call server that queries a register to find if the intended service can be fulfilled; or a billing gateway that evaluates the total bill a customer should pay based on