Current network management needs an end-to-end overview of various connections rather than the information that is purely local to the individual devices. The typical manager-centric polling approach, however, is not adequate to understand network-wide behavior of a large-scale broadband network. We propose a new management information base (MIB) approach, called operation, administration, and maintenance (OAM) MIB. The MIB provides a network manager with dynamic end-to-end management information by utilizing special standard ATM cells. The MIB makes end-to-end management feasible while it reduces management-related traffic and manager-to-manager interactions. In our model, a customer network management system accesses the MIB through M1/M2 reference points of the ATM Forum management architecture with simple network management protocol (SNMP).

A QoS restoration scheme for VP-based ATM networks is proposed and its related characteristics are evaluated. The proposed scheme is a state-independent restoration scheme using a disjoint path group. A VP assignment and capacity planning problem using a disjoint path group are formulated. When a failure occurs, failed working VP are switched to protection paths with the same QoS level using a simple and fast restoration algorithm. The simulated restoration characteristics of the proposed algorithm are presented. A scheme of excess capacity assignment to a protection path for dynamic traffic demands is also presented and analyzed.

Asynchronous transfer mode (ATM) network management is an urgent issue for the fast and successful proliferation of ATM networks. Especially, performance management of ATM virtual connections is urgently required because a different quality of service should be guaranteed on each connection. In most cases, the customer's virtual connections traverse multiple subnetworks, therefore, performance information related to specific user connection is distributed in the networks. This makes performance management of ATM network more difficult. In order to obtain this distributed performance information with current ATM-related management information bases (MIBs), interactions among managers and frequent polling of switches are inevitable. This frequent polling and manager to manager interactions may cause management traffic and data retrieval time to increase. In this article, we propose a performance management method using OAM MIB. The MIB is a set of managed objects which have the information provided by OAM (Operation Administration and Maintenance) cells. The basic concept and structure of the MIB are similar to the RMON MIB. By using the OAM MIB, management traffic and manager to manager interactions are much reduced. In our model, customer network management system (NMS) accesses the MIB via M1/M2 reference points of the ATM Forum management architecture with simple network management protocol (SNMP).

In this presentation, we introduce a fast restoration scheme against a link or node failure. Specifically, we apply this scheme to VP (Virtual Path) restoration in ATM (Asynchronous Transfer Mode) networks. Proposed restoration scheme operates on VP-based ATM network. This scheme is a distributed algorithm performed concurrently by network nodes neighboring failed node or link. When a node or link fails, restoration is performed according to the pre-assigned local, regional, and end-to-end restoration scheme. For this, we assigned a restoration level to each network nodes and VPs, respectively. Also, we devise and construct a VP loop, and fast restoration is performed along this loop. This loop is expanded when a failure occurs, and this expanded loop is used for the restoration of the failed VP connection. We define the required VP loop architecture, restoration messages, and restoration procedures. Proposed algorithm is simulated and compared with general flooding restoration scheme. Results show that the proposed loop-expanding restoration scheme can achieve fast restoration goal with a lower burden to network.

The characteristics of the Estelle specification language are analyzed and a well-defined specification, a restricted form of an Estelle specification, is proposed based on the analyzed results to enable a direct derivation of a single reduced finite state machine-which is called a CFG (control flow graph)-from the specification written in Estelle. The derived CFG provides a basis for the automatic test case generation. Algorithms to test whether the specification written in Estelle is well defined or not, and to generate the CFG from the well-defined specification, are developed. Finally, as an example, the proposed technique is applied to TP0 (transport protocol class 0) specification written in Estelle. In applying these algorithms to the Estelle specification, some guidelines are also suggested for the specification which is not well defined.>

A design approach using simulation to support integrated voice and data (IVD) for a token ring is described. Problems associated with integrating voice and data in token ring protocols are defined. To provide high quality of voice as well as high performance of data over a wide data traffic range, design issues such as voice/data cycle allocation method, limit of maximum data packet size, and packetization period are explained. The proposed approach is applied to the IEEE 802.5 protocol, and its performance is evaluated.>