In a distributed network management environment, a NMS (Network Management Station) interacts with several agents in different sub-networks. In the network fault management context, the NMS detects symptoms that indicate some abnormality e. g. a surge in ICMP traffic, which may be caused by some network malfunction or misuse. The occurrence of a symptom is an event. Large number of events may be detected by an NMS. The sheer number of these events makes it difficult, if not impossible, for an NMS to diagnose these events. Generally, a fault may have a cascading effect which may, in turn, give rise to a very large number of events. The sequence of events and their correlation play an important role in fault management and diagnosis. In the distributed environment of todays networks, the absence of any uniform time for reference makes this a challenging task. In the present network management framework of SNMP, a Manager maintains a notion of the clock of the agent it interacts with. But this mechanism is inadequate to determine the sequence of events and their correlation, more so, in a distributed environment which may involve several managers. In this paper we propose a mechanism for ordering and correlating events detected in large-scale network which is managed in a distributed manner within the SNMP framework. Our algorithm uses the concept of a Network Management Clock (NMC). The NMC is a virtual clock maintained by a manager based on sysUpTime readings from each SNMP agent. In this paper, the algorithm, its implementation and evaluation will be discussed.

The availability of new technologies in the computer and network industry has allowed us to benefit from a wider choice when building new information systems. This paper presents Japan Airlines' challenge to develop a new information network and management infrastructure based on the new technology. Compared with the existing main-frame environment, the new infrastructure will give us a more comfortable and economic network computing environment. Once we think about network management, there are so many issues to be solved. All existing network elements have their own management consoles with different interfaces and commands. Net managers are swimming in the pool of system consoles looking for the one that exactly tells them what is going on at the user site. The industry standard SNMP offers us a much better environment. However, there is still a long way to go before reaching a world where net managers find a single management console with a single object to manage that is composed of all network elements.

As the size and complexity of network increases, the distributed systems management (DSM) will be vital in order to improve the availability of network management, to reduce the complexity of network operations, and to provide the high reliability. In this paper, we (1) describe general requirements required for systems management in distributed environment, (2) introduce the basic structure of distributed network management system (DNMS) for efficient network management, and also especially illustrate the concrete design of system management application process which is an important element among them, (3) propose the connectionless CMIP to accomplish for effectively managing the distributed management system, and indicate its efficiency; this protocol is available to manage dynamically changing DSM environment, to negotiate among the managing systems, to handle the dynamic informations etc. Finally, (4) the behavior and software structure of a suggested management system during negotiation to execute the received request for implementation are presented.