A SYSTEM ARCHITECTURE FOR UPDATING MANAGEMENT INFORMATION IN HETEROGENEOUS NETWORKS Nazim Agoulmine Jose Neuman De Souza zyxwvu (*) Michelle Claud6 zyxw Universid Pierre et Marie CURIE Labratoire MASI UA-8 18 45, Avenue des Etats-Unis 78000 Versailles-FRANCE A B zyxwvutsrqponm S T R A zyxwvutsrqpo C T - This paper presents the architecture and functionalities of a system that permit updating management information, represented by managed objects within the Management Information Base (MIB). These managed objects are an abstract representation of the managed resources of the network. This system interacts with the heterogeneous underlaying networks through a module called Integrator. The integrator prototype was developed at the MASI laboratory and its role is to hide the complexity and the heterogeneity of access to the heterogeneous underlaying resources Part of this work was undertaken within the computing platform group of the ADVANCE project within RACE CEE program. 1 - INTRODUCTION The complexity of computer communication networks has increased in accordance with the rapid progress achieved in various technologies. This complexity has made difficult the management of these systems without a methodical and consistent approach. The trend towards multivendor, multiprotocol, complicates the area of network management considerably. The primary instigators of standardization procedures in this area have been IS0 [ISO10040] and the OSI- NM/Forum[FORUM]. A framework was drawn showing the manner to manage networks conforming to the ISO/OSI reference model and which aspects must be managed. But since the actual networks do not all conform to the OSI/ISO model, the OSI/NM Forum has taken a more pragmatic approach that takes into account the heterogeneity of the network world. The Forum has defined standards for the communication of data between conformant management entities (CMEs). These are network management modules which have to interoperate in the purpose of exchanging management knowledge. The aim of this method is to hide the heterogeneity of network management and components that exist and have a common approach of network management even if the underlying modules and components are heterogeneous. In the first part of this paper we highlight the different sources of heterogeneity and we introduce the integrator concepts. In the second part we describe the update and notification servers wich are the two modules .which compose the model updater system. (*) supported by CNPQ and Banco do Nordeste do Brasil S/A. 999 2 - INTEGRATOR The heterogeneity problem manifests itself when a set of networks are connected together to form an infrastructure for communications. These networks are supporting a set of applications and are composed of components that have different design and technology. 2.1 - Heterogeneity [JP.Claude]: a- Architectural heterogeneity Networks have different architectures (physical as well as logical) depending on their purpose, scope and design. We can find different kinds of network (WAN,MAN,LAN). b- Data heterogeneity New types of networks are appearing to support the different natures of data. Presently, networks are able to carry information of different natures (text, data, voice and image). Management parameters may differ according to the nature of these data. c- Manufacturer heterogeneity When the network components are being developed many non functional requirements intervene into the design. Manufacturers generally orient their products towards a certain range of systems. This leads to a pool of products that have a similar functionality but that act differently. This heterogeneity inhibits the possibility of managing all of the network in a simple manner. In fact, some management systems exist and are .efficient in managing locally their own network components. But when the network is connected to the external world it is impossible to manage the networks as a whole. 2.2 Different approaches to resolve heterogeneity problems These different sources of heterogeneity must be taken into account in order to provide a single view to the management applications, and several approaches to resolve this problem were adopted: a- Standard-based approach: In this case, a reference architecture exists [ISO7498-4] that provides a set of rules, in terms of models, terminology, design framework, for all the management systems to be developed. The conformity of the design style of a new system to this set of rules guarantees its consistency with the rest of the environment. This approach should be the ideal one. However, since the standards impose certains regulations on the design zy of systems, their integrity and stability should be guaranteed. b- Translator-based approach: One of the proprietary management systems is taken as a reference. It offers normalized interfaces for the other We can distinguish several sources of heterogeneity 0-7803-0608-2/92/$3.00 0 1992 IEEE