tain. As ACSE, ROSE, and TCAP are concerned, these standards are unnecessarily complex and too restricted as to their applicability, due to that the LPM-LSM distinction is not applied. In addition, ROSE exhibits a method for describing behavior ("linked operations") that is more damaging than useful. ROSE and ACSE also suffer from misplaced OSI layers (layer 5 and 6), while TCAP has managed to avoid this problem. You can read about this in Sects. 6.2 and 6.3. OSI Upper-Layer Architecture 6.2.1 Introduction During the 1980s, OSI specialists (including the author) believed that the OSI RM and its standards would prevail over other "open systems" concepts, in particular in its competition with the Internet architecture. For example, in Rose (1990) we could read: The OSI model will join and eventually displace the Internet protocol suite as the off-the- shelf commodity of choice The OSI suite eventually will dominate, then eclipse and finally make the Internet suite "immaterial." The fact that the evolution of open systems has not only gone completely in another direction (the Internet way), but has also made the OSI RM an almost for- gotten architecture, is not only due to the fact that there are millions of TCP/IP- based systems deployed today. It is as much the architectural solution that is repre- sented by the OSI RM, which is too complex, too inefficient, and above all, too implementation-oriented. Nobody should apply it today. The discussion here is of interest not only because it demonstrates the power of AMLn, but also because it demonstrates the negative effects of applying a software engineering approach to network architecture, and because parts of this architec- ture (ACSE and ROSE) represent an original initiative of defining common agent layer functions (and has inspired AMLn in this respect). The OSI architecture for layers above its transport layer (layer 4) is (in princi- ple) not possible to model in AMLn. Besides that AMLn defines a generic solution for modelling any layer (the actor-agent separat