Network Management

The objective of the Astrolog action, carried out in the framework of Dyade joint venture between INRIA and BULL, was to investigate what can be the benefit of Internet technologies for network and system management. In the general term management, we traditionally distinguish on one hand network management which deals with hardware and low level software layers controlling hardware network elements, and on the other hand, system management, which is related to the maintenance of operating systems and user software installed on the various machines. My work comprises of two parts: the design and implementation of a uniform environment for heterogeneous system management and the design and implementation of a network management environment based on the mobile agent technology.

Management of Heterogeneous Systems

System management comprises various activities that depend on local constraints such as users requirements, number and type of equipments. System heterogeneity is one of the main problem in the design and implementation of a management system.

The objective of my work was the design of a uniform environment for heterogeneous system management (joint work with Stéphane Billiart). We have proposed a new approach based on the definition of a unique interface for accessing management functions that masks the particularities of the different systems. Our approach is to first identify basic components on which system management functions can be applied. Then, components ensuring equivalent functionnalities are combined into entities. Each entity offers a unique interface whichever the system on which it is used. It deals internally with heterogeneity problems and executes management tasks on the different systems taking benefit of their particular functionalities.

This approach has several advantages. First, it is simple to deal with heterogeneity between different systems on small components of weak complexity and with well-defined functionalities. Moreover, it is possible to reuse and combine several entities to create more complex elements with extended functionalities. Adding new functionalities such as supervising new hardware or management of new services is easy as well as the integration of existing management services.

Our approach has been validated by the implementation of a system management environment based on entities for the Astrolab platform, which isa local area network of heterogeneous workstations running different operating systems (AIX, Solaris, Linux, NetBSD, Windows NT). Our prototype has been designed to be flexible and several interfaces are available for users or external applications. An attractive user interface based on the Web has been built allowing uniform access to the management environment for any kind of system in use and for every functionalities.

Network Management based on the Mobile Agent Technology

Networks and distributed processing systems are of growing importance and indeed have become critical to organizations. The proper functioning of such networks is thus of great importance to these organizations. The administrators are responsible for managing these networks and utilize network management systems for the purpose. The management of network comprises of monitoring and control of a network. It plays an important role in the configuration, proper functioning, and maintenance of a network. Network management involves amongst other things the collection and visualization of network data, identification and management of faults, configuration and altering the behaviour of network components, and security management and control. Traditionally, a network management system relies on a management platform which executes the different network management applications and on which network management information is stored. The management platform communicates with the network elements through specialized management protocols such as SNMP or CMIP. Such a protocol is instantiated on each network element by an agent which collects management information, answers to requests from the management platform and notifies events.The task of network management relies heavily on the competence of the administrator to discern the large amount of available network data and to take the necessary actions. This necessitates the continuous presence of the administrator in the proximity of the management platform, specially during network breakdown and outages. However, as the network faults can arise randomly, it is often not the case. In case of an emergency, the administrator receives a cryptic pager message and one of the recourse left to the administrator is to rush to the management platform.

The objective of my work was the design and implementation of a Mobile Network Manager (MNM) which allows an administrator to manage the network in a system and location independent manner (joint work with Akhil Sahai). The MNM can execute on either workstations or portable computers connected to the managed network by a phone line or a wireless network. In this context, we have implemented the Astrolog network management system. The Astrolog network management system is based on the mobile agent technology. The mobile agents are utilized to distribute the network management functionalities thus decreasing the load of the management platform. They also permit the disconnected functioning of the Mobile Network Manager. A mobile agent is a program which can autonomously migrate from site to site. In our context, an agent can be sent in the managed network from the portable computer to collect information on different sites. During the agent travel, the portable computer can be disconnected. This allows to save power and to limit the duration of the costly connection to the network. Moreover, treatments (filtering, information grouping, ...) performed by the agent during its execution in the managed network allow to decrease the amount of data transmitted as result to the portable computer.

We have designed and developed our own mobile agent environment called Magenta. The Magenta environment provides support for mobile computing, fault tolerance and innovative mechanisms for the execution of mobile agents.

The Astrolog and Magenta environments have been implemented in Java. A detailed performance evaluation of the Mobile Network Manager has been carried out. In this context, we have compared the client/server and mobile agent technologies in the domain of network management.