me time some functions of these blocks are outside the scope of TMN which are not discussed in this book. The functional blocks are: Operations Systems Function (OSF) block processes information related to the telecommunica- tions management for the purpose of monitoring/coordinating and/or controlling telecommunication functions including management functions (i.e., the TMN itself). Network Element Function (NEF) block communicates with the TMN for the purpose of being monitored and/or controlled. The NEF provides the telecommunications and support functions that are required by the telecommunications network being managed. Mediation Function (MF) block acts on information passing between an OSF and NEF. Q Adapter Function (QAF) block is used to connect as part of the TMN those non-TMN entities which are NEF-like and OSF-like. The responsibility of the QAF is to translate between a TMN reference point and a non-TMN (e.g., proprietary) reference point and hence a portion of this function block is outside the TMN boundary. Table 8.1 Relationship between the logical function blocks and reference points [25] QAF qx non-TMN q3, Xa non-TMN a X reference point only applies when each OSF is in a different TMN. The g reference point lies between the WSF and the human user. Note: Any function may communicate at the non-TMN reference point. These non-TMN reference points may be standardized by other groups/organizations for particular purposes. Source: C ITU-R 1996 [25]. Core Networks and Operations Support Systems 8.3.3.1.2 TMN Information Architecture The information architecture usually takes an object-oriented approach for transaction-oriented infor- mation exchanges. The TMN methodology makes use of the OSI systems management principles and is based on an object-oriented paradigm. Management systems exchange information modeled in terms of managed objects. Managed objects are conceptual views of the resources that are being managed or may exist to support certain management functions (e.g., event forwarding or event l