With the dramatic rise in the number of Internet users, the expansion of international corporate activity and the arrival of multimedia services, highly-competitive information and communication services are entering a period of severe global change. There is widespread recognition that as these changes take place, it is important to establish operation and management (O&M) that will enable "seamless" end-to-end communication services between any points on the earth. With worldwide trends moving toward automation, the study of automation of O&M is being energetically pursued. This paper describes the requirements for service O&M and gives an overview of the technology believed to be essential to achieve them. The progress of developments is also reported.

This paper reviews the business reasons why telecommunications service providers and network operators are moving to standardise key aspects of the management of their networks and services, and how the international definition of the Telecommunications Management NetworkTMNfits within current business strategies. It discusses the potential benefits of TMN implementation as well as some pitfalls that must be addressed in order to gain its full potential, including the technical evolution of the TMN framework to take advantage of advances in distributed object-oriented computing. TMN had its beginnings prior to the commercial and regulatory upheaval that now rocks the telecommunications industry world-wide. The focus of investment-toward a lean, competitive positionrepresents a significant change from the days when TMN was first beginning to be defined. This shift in emphasis, from a network-centric view to one that recognises the value of fast, accurate customer response and operational efficiency, has heightened the need for a standard way of managing within companies and across company boundaries. TMN is the best model the industry has for achieving standardisation. But the TMN model, in order to really meet the needs of industry going forward, must be interpreted more broadly than it has been in standards. We do not argue that TMN is in any way wrong, indeed we applaud the progress made to date.

Rapid advancing technology and customer demand for sophisticated services are driving the global telecommunications environment into fully competitive and multi service providers environment. To cope with this new environment successfully, open network and open telecommunication management are essential. Telecommunication management is becoming more and more important to realize flexible and dynamic telecommunication services. This paper first gives a view of the new environment in the telecommunication industry and discusses the direction to be taken by service providers. Then, a concept of multi-domain management is proposed to meet a dynamically changing environment. Finally, the paper describes the subjects for the development of telecommunication management system and suggests that a competition based on harmony between the users, service providers and vendors is needed to make customers satisfied with telecommunication services.

There is now a world-wide trend towards the downsizing of information systems using a number techniques, such as clientserver architecture. Consequently, enterprise networks are fast growing in terms of size and functionality. These networks need to be managed effectively. Researchers have been working on the development of management solutions for enterprise networks, using recent advances in software engineering, communication protocols, and artificial intelligence techniques. However, not much work has been published on the role of human factors in the integrated management of networks and systems. This paper presents a new Cooperative management Methodology for Enterprise Networks (CoMEN), based on Computer Supported Cooperative Work (CSCW) techniques.

As enterprises use ATM networks for their private networks and as these private networks use public ATM networks for wide area communication, the need for the customers to be able to manage both private and public networks is increasing. Currently, some standardization work is being done towards providing this capability to customers. In this paper, we propose a new customer network management (CNM) system architecture for the management of both private and public ATM networks in a uniform way. The particular features of the proposed architecture lies in the efficient support of the complex hierarchical TMN manager-agent relationships at M3 and M4 interfaces, and the support of SNMP and CMIP integration. The TMN hierarchical many-to-many manager-agent relationships are realized by the utilization of a CORBA-based Shared Management Knowledge (SMK) system. We have implemented a prototype of ATM CNM system, and measured the performance for the demonstration of the suitability of the proposed architecture.

Given the recent advances in telecommunication services, new service operations are needed that support not only existing network services, but also information and communication providing services, such as multimedia services. It is particularly important that service usage information should be gathered, processed, analyzed and presented properly for smooth service provisioning and business support. This paper defines a reference model for service usage information and an implementation model for establishing the functions needed to gather and process this information. The results of an service operation system as implemented in NTT multimedia service trials, currently underway in the city of Urayasu, are also described.

We have studied the flowthrough operation to simplify operation processes and to promote the efficiency of operation flows. In this paper, we introduce the Construction Manager System (CMS) that cooperates with the ATM Transport Network Operation System (ATMOS). This system directs the construction processes using the construction tickets newly defined by the GDMO (Guidelines for the Definitions of Managed Objects); these tickets and action scenarios are prepared inside the SMS (Scenario Management System). We confirm that CMS can perform construction management using the construction tickets instead of the traditional off-line communications such as the telephone and the facsimile. Furthermore, because CMS cooperates with ATMOS, it is able to manage actual network elements (NEs) and conduct board costruction processes by using construction tickets. Moreover, CMS can confirm that the construction processes of the actual NEs have actually been executed through the Q3 interface. As a result, we verify the basic technique for flowthrough operation for configuration management.

Today's enterprise information systems are modeled on the client/server paradigm over LANs interconnected by WANs, but it involves problems of network management costs and complicated management jobs. So efficient network management is strongly required for LANs interconnected by WANs. In this paper, we describe a hierarchical enterprise network management system for LANs interconnected by WANs, based upon analysis of LAN management operations. This network management system has a hierarchical model with three levels, i.e., center level, area level, and user-site level. We also describe how this system was implemented as a nation-wide corporate network with many LAN sites, emphasizing on its functional structure. This network's success has confirmed usefulness of the management system.

In the future PCS (personal communication system), it is needed to use wireless and wired resources most efficiently, because of the increase of users and various multimedia traffics. Therefore, there have been much researches on CDMA (code division multiple access) whose frequency reuse is most efficient. Here, if one of PCS subsystems is broken down because of system, power, or network failure, it is impossible to serve PCS user terminals anymore. To solve this problem, the integrated network management function is required to examine each subsystem periodically or non-periodically, and handle each error properly, and inform network manager or PCS service management center of error occurrence. In this paper, we consider standard SNMP (simple network management protocol) and CMIP (common management information protocol) as the management protocol of PCS land mobile network. Also, we present the overall structure of management information taking CDMA PCS characteristics into consideration. Since there were little considerations for characteristics specific to cellular environment in the conventional network management systems, we add the CDMA PCS-specific management informations to each agent systems. Thereafter, we present the optimum network management protocol stack for PCS environment which provides TMN (telecommunications management network) interfaces among each subsystems as well as including wired networks.

Private networks are becoming globalized and more complicated through LAN-WAN interconnection. While WANs are managed by CMIP, LANs are managed by SNMP. To achieve end-to-end management, the integration of CMIP-based and SNMP-based management is important. We have developed an MI (Management Integration) platform for CMIP-based and SNMP-based management. It provides OSI SMF (Systems Management Function)-based unified basic management services to upper level applications regardless of the differences between CMIP-based and SNMP-based management. It achieves this with two modules: a management information transfer integration module that mainly covers protocol and data format differences between them, and a basic management module that covers functional differences. The translation of management information in the former module can be changed flexibly because the translation is based on an external script file. The latter module has additional SMF-like functions for the management of SNMP agents in addition to SMF manager role functions, etc. Prototype evaluation has demonstrated the feasibility of the MI platform.

As the Asynchronous Transfer Mode (ATM) technology comes to be used widely, the Telecommunications Management Network (TMN) over ATM networks becomes an important issue. Since TMN uses the OSI protocols including the Common Management Information Protocol (CMIP), it is required to implement CMIP communication over ATM networks. In order to realize OSI over ATM, ITU-T SG13 has standardized the Service Specific Coordination Function for Connection Oriented Network Service (SSCF-CONS), Service Specific Connection Oriented Protcol (SSCOP), and the Synchronization and Coordination Function (SCF). We have developed the CMIP software over ATM networks adopting these protocols. The CMIP software is designed so that it achieves both high throughput for large data transfer and short response time for small message exchange. The software adopts the implementation mechanisms commonly applied for protocol modules to reduce the overheads for controlling OSI protocol modules, and some protocol specific mechanisms especially for protocols with heavy processing overheads, i.e. SSCOP and CMIP. The performance evaluation shows that the developed CMIP software achieves more than 200 message exchanges per second for messages whose length is 64 Byte long, and achieves about 36 Mbps throughput for transferring data whose length is more than 100 KByte.

In OSI management, we utilize a scope parameter in Common Management Information Service (CMIS) that enables us to operate multiple Managed Objects (MOs) at one CMIS operation, so that we may reduce the number of communications between a manager and an agent. The more the number of MOs increases, the harder it is to find optimal combinations of scopes. In an existing approximation algorithm for finding optimal combinations of scopes, there are restrictions on the structure of a naming tree for the algorithm to work efficiently and the lower bound of its approximation ratio, n/4, grows in proportion to the number of MOs, n. This paper proposes a new approximation algorithm that removes the restriction on the structure of a naming tree and significantly improves the approximation ratio to (1 + ln n) in the upper bound, by keeping the same time complexity as the existing algorithm.

This paper discribes the ISDN PROtocol Testing system (I-PROT). The system consists of translation & distribution function block, layer-2 fault surveillance function block, layer-3 fault surveillance function block, cause detection function block, and HMI. The system receives data from protocol monitors and detects the error recovery sequences, (we call "quasi-normal sequences"), as well as the sequences that do not follow the protocol specifications, (we call "abnormal sequences"). In the layer-3 fault surveillance function block, we use the protocol specification database whose records are converted from the state transition rules and added the judgment which classify the rules into the "normal" and "quasi-normal." We also show the classification method which is applicable to all connection-oriented protocol specifications. In the layer-2 fault surveillance function block, we explain the another easy detecting method. In the cause function block, we describe the partial pattern matching method to relate the protocol fault to the real cause of the fault. We built the prototype of the I-PROT and examine the turn around time (TAT) performance. As a result of the examination, we find the TAT of the I-PROT is directly proportional to the number of the frames analyzed by the system, and the system can reduce the load of the conventional manual analysis by the maintenance personnel.

The Telecommunications Management Network (TMN) is a major focus of telecommunications operations work in the 1990s. New telecommunication equipment is required to conform to the TMN standards. In the TMN, a network element is managed as a set of Managed Objects (MOs). The MO program has to be executed in a muiltithreaded, parallel environment for a quick response; therefore, concurrency control is a key issue for developing an MO program. This paper proposes a formal definition to specify data for concurrency control to improve the correctness and reusability of the specification. The definition is based on a Generic Relationship Model (GRM). By using the formalized definition and developing an algorithm to translate the definition into executable code, concurrency control is performed without coding. After describing the algorithm used to perform concurrency control, this paper discusses a three-layer concurrency control architecture to accommodate this framework efficiently.

We have developed a management agent that adapts the delegation concept to achieve efficient network management. In conventional delegation architecture, a network management operator details management operations in an operation-script that describes management operation flow and such network management functions as event management and path tracing. The operator sends this script to agents to execute. In our delegation architecture, the operator sends only a script skeleton describing management operation flow alone; management functions are built into the agents in the form of fuction objects. This helps keep management traffic low. Each function object is designed by utilizing three operational objects: enhanced, primitive, and communication. Each enhanced operational object (EOO) provides a script skeleton with an individual network management function. A primitive operational object (POO) provides an EOO with managed object (MO) access functions. A communication operational object (COO) provides an EOO with a mechanism for accessing the functions of other remote EOOs. We have tested our design by applying it to a path tracing application, and we have measured the total data transfer size between a manager and an agent and the amount of memory usage in our agent's running environment. Evaluation of our implementation suggests that our design can be applied such network management functions as connection establishment and release, fault isolation, and service provisioning.

This paper describes the effectiveness of stream-oriented data-driven scheme for achieving autonomous fault management of hyper-distributed systems such as networks based on the Telecommunications Information Networking Architecture (TINA). TINA, whose specifications are in the finalizing phase within TINA-Consortium, is aiming at achieving interoperability and reusability of telecom applications software and independent of underlying technologies. However, to actually implement TINA network, it is essential to consider the technology constraints. Especially autonomous fault management at run-time is crucial for distributed network environment because centralized control using global information is very difficult. So far many works have been done on so-called off-line management but runtime management of service failure seems immature. This paper proposes introduction of stream-oriented data-driven processors to the autonomous fault management at runtime in TINA based distributed network environment. It examines the features of distributed network applications and technology requirements to achieve fault management of those distributed applications such as effective multiprocessing of surveillance, testing, reconfiguration in addition to ordinary processing.

An advanced intelligent network (IN) provides service management along with telecommunication services, and has a two-layer architecture, i.e., a transmission layer and an intelligent layer. An advanced IN's programmability is achieved by a service-independent platform of nodes in the intelligent layer, and service-dependent software called logic programs. In contrast to telecommunication services, models for service management have not yet been established. This paper presents both execution and specification models for service management. The execution model is composed of three hierarchies that apply to various kinds of management operation. The specification model has the capability to define the details of data items. The specification language for service management is also proposed. Simulation on dynamic SQL based DBMS solved that; (1) Logic programs for service management can be made small size on the model, and (2) To provide efficient database operation, programmability must be enhanced if service management includes table with variable number of field operation.

This paper proposes the Snow Crystal method, which aims to present the hierarchies of a large-scale telecommunication network on one screen. This will improve the user interface of a network operation system for network operations and management. With the proposed presentation method, locations of nodes are automatically set based on the number of hierarchy levels and the number of nodes. The nodes in the same hierarchy level are located on the same circle at even intervals. The center of the circle that corresponds to the top hierarchy level is set at the center of the screen. The radius of the circle is determined by the number of nodes. The centers of circles that correspond to the second hierarchy levels belonging to the nodes of the top hierarchy level, are located on a larger circle with the same center point as the top level circle at even intervals. The centers of circles that correspond to the third hierarchy levels are located at even intervals on a circle with the same center point as the second level circle, which the third levels belong to. The nodes of the subsequent levels are located in the same way. The proposed presentation method is successfully applied to a large-scale telecommunication network. Moreover, the results of an operating experiment with the proposed method show its effectiveness for presenting hierarchies of large-scale telecommunication networks.

We consider the problem of designing a physically diverse network that can support any two simultaneous node-to-node traffic flow requirements as called for by special events such as communication link failures or surges in network traffic. The design objective is to obtain a network with the minimum level of network capacity, yet robust enough to handle any two simultaneous traffic flow requirements between any nodes. To arrive at the minimum necessary network capacity,we introduce the concept of nodal requirement. Based on nodal requirements, we can build what may be called uniform protection subnetworks for equal nodal requirements. Successive uniform protection subnetworks can be built for incremental nodal requirements. This direct approach supersedes the extant work on building fully connected networks or loops from maximum spanning trees that can cope with only one traffic flow requirement. Our nodal requirements approach generalizes well to multiple simultaneous traffic flow requirements. Hub subnetworks are introduced to provide protection for networks with a unique node that has the largest nodal requirement. Further, a heuristic is considered and analyzed that assigns edge capacities of the protection network directly based on the largest two traffic flow requirements incident on the end nodes of an edge. The heuristic is attractive in being simple to implement.

A neural network approach called the "Gradual Neural Network (GNN)" for the time slot assignment problem in the TDM multicast switching system is presented in this paper. The goal of this NP-complete problem is to find an assignment of packet transmission requests into a minimum number of time slots. A packet can be transmitted from one source to several destinations simultaneously by its replication. A time slot represents a switching configuration of the system with unit time for each packet transmission through an I/O line. The GNN consists of the binary neural network and the gradual expansion scheme. The binary neural network satisfies the constraints imposed on the system by solving the motion equation, whereas the gradual expansion scheme minimizes the number of required time slots by gradually expanding activated neurons. The performance is evaluated through simulations in practical size systems, where the GNN finds far better solutions than the best existing altorithm.

The interworking between high speed networks is receiving more attention recently. Among them, Frame Relay/Asynchronous Transfer Mode (FR/ATM) interworking is foreseen in the near future to provide seamless service across geographic areas. In the heterogeneous network interworking environment, an interworking function facility called the interworking unit (IWU) is generally interposed between these networks to perform the essential protocol conversion. As an intermediate network component, IWU will have great influence on network performance in terms of data latency. The performance issues of IWU are identified and addressed in this paper. These issues include frame processing schemes, frame shaping schemes, and cell processing schemes. The cell processing performance issues are further investigated via simulation experiments. Connectionless (CL) data service is also expected to be one of the most important applications for FR/ATM interworking. Some alternative methods for providing CL service over FR and ATM are described. We propose an enhanced protocol stack in the IWU to interoperate with the ATM network which uses the direct method to provide CL service. To proveide VPN service, we propose a feasible VPN communication structure based on the FR and ATM network interworking.

As the number of different video compression algorithms in use and also the specific bit rates at which they are operated increase, there is a growing need for converters from one algorithm or bit rate to another. In general, this can only be accomplished by decoding and re-encoding. It has previously been assumed that the additional delays introduced by such decoding and re-encoding are additive and thereby become unacceptable for some interactive applications. This paper shows that it is possible to construct a transcoder such that the aggregate end-to-end delay is substantially less than the sum of the delays from the two encode and decode pairs. Two techniques are described. The first is more general while the second is simpler but is restricted to the case of reducing the bit rate and keeping the same compression algorithm. Results from simulations of the latter method are included.

Conformance testing is to see if the protocol implementation conforms to its specification. A lot of test sequences have been developed for testing centers. Yet directly applying these test sequences to the simple testing system in laboratories suffers from the frequently-occurred synchronization problems. This paper proposes a new technique to disconnect a test sequence into segments based on their functions, and reconnects them into a new test sequence that simulates these functions yet suffers less from the synchronization problems.

Users of computer communication systems and their requirements are rapidly increasing and changing. It is desirable to have a development method which helps to make small changes in a design of a system to obtain another system which satisfies new requirement changes. We propose a flexible synthesis method which adopts designers' requirement changes in formal protocol specifications designed in LOTOS.