res for management systems that are described in this chapter are taken from the TMN concept (the ITU-T reference model for management systems), but modified and adapted to AMLn modeling concepts. In TMN, these systems are named "managed system" and "managing system," respectively. 5 Management and Traffic Systems Since a traffic system is a network system, it follows that a management system is a network system as well. Therefore, the two systems each define their own planes of L dimensions and N dimensions, as depicted in Fig. 5.1. The traffic plane is defined as the LT-Nr plane, the management plane as the LM-NM plane. An L dimension defines all layers and all types of connectivity service points (CSP), user control points (uCP) and resource control points (rCP) in the layer structure of the system (as defined in Sect. 2.1.1). The N dimension defines the nodes and routes of networks that build up the system. manages Traffic Management functions functions serves Fig. 5.1 Functions of a management plane (M) manages resources of a traffic plane (T), and func- tions of a traffic plane may offer connectivity services to functions of the management plane Thus, each of the planes defines its own layers and nodes. There are two types of relations between the planes: 1. One is a "manages" relation. On the level of functional elements, management functions control managed resources (tables, devices, etc.) of layers in the traffic plane. Conceptually we model this by managed resource control points (mrCP) between elements of the planes. 2. The other is a connectivity service relation, denoted CSPM in the model. This relation is used by management functions that run on connectivity layers of the traffic plane. The structure of mrCP and CSPM between the planes define a completely new, orthogonal dimension, the management dimension (M), as depicted by Fig. 5.1. In order to be able to create models that relate traffic plane elements to manage- ment plane elements, we must first define the distinction between the behavior of 