Information Model: From Abstraction to Application

Abstract

Today’s telecommunication structures, already widespread, are based on heterogeneous systems. In fact, in most networks, there are products and services from multiple vendors, and these products incorporate multiple technologies. So how can we manage networks which coexist, cooperate and internetwork in heterogeneous environment? As a matter of fact, we can say that management of network needs to have information on the whole behavior of all network elements. Thus, an information model must be provided, describing the way in which information is structured. We know that this information model is a critical component of a network management framework. Which are the main contributions of network management standards in this area? OSI management standards have adopted the object oriented paradigm for definition of management information [1]. Also, a semi-formal notation for the description of the syntactical elements of managed object classes, GDMO [2], has been defined. In addition, managed object sets (libraries) [3], are provided for developing its own specific information model. However, there is no provision of structuration of the information. On the contrary, CCITT [4] provides a generic network model without distinguishing between network and network element viewpoints [5] and without enhancing the service aspect. However, Network, Network Element and Service views are primordial for integrated management. The Internet community defines the MIB II (Management Information Base) [6]. The information is only attribute oriented. This is mainly for reasons of simplicity and quick provision of an operational network management framework. A main drawback is the lack of powerful modeling concepts. Each standard provides some elements of solution. However they still do not propose an integrated information model. In order to provide a complete answer that meets all requirements, it is necessary to reply to the following questions: Which are the main objectives of a satisfactory management information model? Which are the necessary conceptual tools? The answers lead us to propose an object oriented information model supporting both network and service aspects, which may be applied to any network element according to a particular visibility. To pass from this abstract model to its instantiation for a particular network configuration, we focus on the FDDI subnetwork management. Throughout this application, we enhance its efficiency for monitoring, controlling, analyzing and eventually managing the studied configuration. In addition, we provide the basic rules that guide us during the instantiation of the abstract model for any specific network.