n adaptation function (AF) in the same node. The AF is the ESM in an actor that uses a management plane agent layer for communication with the OSF. The SAG is denoted SAGM, where "M" denotes that it connects to an agent layer of the management plane (which may, or may not, be common for the two systems). 5 Management and Traffic Systems The model shows that we must distinguish between mpCPs that describe the interaction between management elements in the two systems, and mrCPs that are local in traffic-system nodes and describe the interaction between an AF and local resources. The purpose of an AF is to adapt to interfaces of local physical resources on which traffic system actors rely. These mrCPs consists of control and test points of resources that are first defined in implementation models, and are therefore proprietary (i.e., not standardized). mpCPs between the two systems are subjects for standardization³, since one wants a single management system to be applicable to all types of traffic sys- Similar to all control points, mpCPs are functional interfaces, which means that they can be described as abstract protocols. In all control points, one element (the OSF here) is the controlling party, the other (here the AF) the controlled party. This means that an mpCP abstract protocol is fairly simple, defining (more or less) a number of operations that an AF can perform, mostly upon request from an OSF. This paradigm can be supported by the AMLn-SAG, as well as by TCAP and ROSE agent layers. What complicates things in mpCPs is that one wants to be able to refer not just to operations but to operations on particular managed resources. These resources are therefore specified as managed objects (MO), as shown in Fig. 5.4. Since the AMLn-SAG supports object references (see Appendix B), it can also support mpCPs. TCAP and ROSE are, however, not sufficient in this respect, which is why ITU-T had to define additional functionality for supporting MOs (i.e., CMIS/CMIP, see Sect. 5.3.3). TS-node Fig. 5.4 In communication