This paper proposes a new approach to the management of large-scale communication networks. To manage large-scale communication networks effectively, it is essential to get a bird's-eye view of them when they are in their normal conditions. When an indication of faulty state is detected, the focus of the management is narrowed down to the faulty network elements until the appropriate granularity is reached. This management scheme is called multilevel network management in this paper, and it first explains the significance of this scheme for large-scale communication networks and presents some ideas on implementing this management scheme. It then proposes that system identification be used in multilevel network management. The system identification is used to measure transmission delays between two arbitrarily selected nodes in the networks, and multilevel network management is achieved by selecting those two nodes appropriately in accordance with the levels to be managed. Finally, it is demonstrated by computation simulation results that the proposed method is suitable for multilevel network management.

A distributed network management system (NMS) is urgently needed to manage large number of network managed objects (MOs) such as public network MOs. The ATM Forum has proposed the M4-interface to achieve just such a distributed NMS. However, the basis of the M4-interface is not adequate in terms of flexible distribution, because its main unit of distribution is location. To improve the granularity of the distribution, we have defined the route as a further unit of distribution. We also describe new MOs that provide for a distribution based on routes. A more detailed distribution is then possible than with a distribution purely based on location. In addition, we propose a new CMIP Action to move MOs from one sub-NMS (SubNMS) to another while the system is running. Using this Action, we can achieve a more flexible distribution in terms of network problems and load.

This paper discusses a way of identifying the network configuration of ATM-LANs, which are composed of a number of ATM hubs. In general, a Network Management System (NMS) sets and gets the necessary data to and from the network elements. In managing an ATM-LAN, the ATM connection between the NMS and each network element, namely the ATM hub, must be established in order to get and set the necessary data. This forms a remarkable contrast with conventional LANs such as the IEEE802.3 LAN, which is a shared media network and enables broadcast communication without setting up any connection. This paper proposes a new protocol and a procedure that establishes the ATM connection between the NMS and each ATM hub, while identifying the overall network configuration. First, this paper makes clear the peculiarity of the ATM-LAN in terms of automatically identifying the network configuration. Next, the identification protocol that achieves the required properties is precisely explained. Then, the proposed identification protocol is evaluated in terms of required bandwidth and identification time.

This paper describes a new method to estimate traffic load of communication nodes, such as switching systems. The new method uses the system identification, which is often used in designing control systems of real systems. First, this paper makes clear that, under certain conditions, the input and output relation of a communication system, which is composed of a number of communication nodes, is formulated into a dynamic state equation that is classed as a time-invariant, single-input single-output, discrete-time system. Next, it is explained that traffic load information is estimated by identifying the dynamic state equations of the communication system. Then, the traffic load estimator is synthesized using the system identification in it. Finally, it is clarified by computation simulations that the proposed method is very applicable in estimating the traffic load of each communication node.