ptor. So in a multitechnology (underlying protocol), multivendor environment, where interaction between EML and NML is not standardized, for an NMS to Fundamentals of EMS, NMS and OSS/BSS collect data from multiple EMS or for an EMS to be used with multiple NMS, the possible method of operation would require writing multiple adaptors. Writing adaptors is not a cost-effective option in the evolving telecom industry where the major investment could end up in writing adaptors. Hence there was a need to have standards for interaction between EML and NML. For the interaction to be standardized, the following basic requirements need to be satisfied: Messages for communication must be predefined (e.g., getActiveAlarmList, getConfiguration) The objects must be well defined (i.e., a common naming convention needs exist for addressing the managed and management objects) The definitions must be independent of the management protocol used It should be applicable for multiple networks based on different technology Vendors must accept to the standard and make their products compliant Use of these standards leads to ease of integration, in addition to reduced cost and time of integration. Multi-Technology Network Management (MTNM) model of TMF ensures interoperability between multivendor Element and Network Management Systems. It mainly consists of a set of UML models and CORBAIDLs to define the EML-NML interface. This chapter handles the basics of MTNM by discussing the four main artifacts that were release by TMF describing MTNM. 8.2 About MTNM The first initiative in the development of an EML-NML interface was SONET/SDH information model (SSIM) of TMF. When TMF509, the first version of SSIM, got industrial acceptance another team ATM information model (ATMIM) was formed for working on ATM networks. Later SSIM and ATMIM teams merged and formed a MTNM team for jointly defining standards in EML-NML interface. Some of the functional areas in telecom management covered by MTNM are: Configuration management: This includes network 