This paper proposes a Java online plug-in mechanism that can be used to modify any part in a system file coded in Java, even while the part is running, without service interruption. The Java-related plug-in capabilities are devised by using the plug-in functional elements offered by the existing C++ online plug-in that we proposed. In particular, measures on how to deal with the use of Just In Time compilation and inline expansion are considered. New linkage and file-back up techniques are proposed for this purpose. Case studies reveal its wide applicability and the degree of memory area saving effects. Evaluation proves this mechanism does not affect the performance of ordinary service processing. It is expected to be used in practice for Java-based service processing such as VoIP and Instant Messaging.

The introduction of networks providing Internet-like services such as the Open Computer Network (OCN) by NTT and others like it will lead to higher level demands by users. For example, users will be asking for higher quality, greater functionality, and lower charges for high-speed, high-throughput data transfer. To respond effectively to the wishes of sophisticated and varied users, technological development must be pursued from the user's point of view. For this reason, research and development is being performed on middleware to open up network functions and make it possible for the user and network to cooperate with each other. This paper discusses the development of major technologies for achieving an enhanced internetworking that should become a catalyst for the future multimedia network, and presents a future vision for the network.

This paper presents a layered hierarchical switching-software technology, which is based on an object-oriented design approach, that improves software reusability and productivity. This technology enables a non-stop, service-enhanceable software environment (called NOSES), which satisfies customer demands for quick provisioning of new service features without interrupting service, and which improves software reliability. This technology was developed as part of our overall plan to establish a communications software platform that can be customized for use by various communications systems, such as STM, ATM, and IN. The developed non-stop service enhanceable software techniques are call-recovery restart, system file update, and on-line partial file modification; they were achieved by using dynamic program modification. A system file update inevitably affects calls in service, despite efforts to save in-service calls by copying the call data from the old file to the new one. We have therefore developed a different approach: on-line partial-file modification. Our prototype switching system has proven the effectiveness of this modification method and has shown that it can cover a limited range of service feature additions (which meets customer demands for quick service provisioning), as well as all bug fixes (which can lead to higher software reliability due to not using conventional machine code for software patching), without interrupting service. This paper describes on-line partial-file modification, which can be applied to communications systems that require resident program modification or initialization without program loading; that is, the program exists permanently in main memory. An evaluation of this approach also showed that the productivity of service-layer software increases about two times and that the total increase in systems development productivity is about 25%.

The Non-stop Service-Enhanceable Software (NOSES) platform was developed as part of our overall plan to establish a communications software platform that can be customized for use by various communications systems, such as STM, ATM and IN. The developed NOSES techniques are call-recovery restart, system file update, and on-line partial file modification, so called "Plug-in"; they were achieved by using dynamic program modification. A system-file update inevitably affects calls in service, despite efforts to save in-service calls by copying the call data from the old file to the new one. We therefore developed a different approach: Plug-in modification. This paper evaluates the applicability of the plug-in mechanism of the NOSES platform. Plug-in is a dynamic partial-file modification technique that does not affect calls in service in a communication switching system. In order to apply plug-in program modification widely, the static and dynamic properties of the modified software must be considered. Therefore, an applicability judgement matrix is introduced. The evaluated applicability of plug-in based on case studies and field data was about 60% for service feature additions and modifications. Thus, plug-in is effective for file maintenance of switching systems from the viewpoint of quick provisioning of new service features and bug fixes.

This paper describes two main technologies for achieving reliable real-time distributed communications systems. One is the technology to prevent the influence of a fault in an autonomous distributed system from spreading to the whole system (called autonomous distributed system control). The other is a software structure based on distributed processing, the object-oriented approach, and layering for better maintainability and expandability (called OO software structure). For the autonomous distributed system control, several inter-subsystem communication methods are proposed and evaluated. From the standpoints of the fault processing and processing load, frames should be sent through a data link over ATM connection and when a fault occurs the link should be switched over without loss of data. A pilot system achieved good reliability without an excessive number of dynamic steps. This autonomous control method will lead to a highly reliable communications system with large capacity. For the OO software structure, this paper gives experimental results from the implementation of a prototype system. Its distributed environment should lead to high reliability by extending the CHILL run-time routine (RTR). This software structure promises to provide service quickly, to reduce costs, and to make the development of each layer's software independent. A real-time OS, e.g., CTRON kernel combined with RTR can give real-time performance, high reliability and high productivity over the distributed system. The use of RTR can reduce the time for the call recovery process.

A highly reliable, operated efficiently, and scalable switching node is required for multivendor system management networks. This paper presents techniques for applying the Telecommunications Management Network (TMN) concept to a distributed switching node. First, we select the TMN protocol structures so as to minimize the command response time. To ensure efficient operation and flexible design of the operation, administration and maintenance (OA & M) software, we propose a command-message handling function for mapping managed objects (MOs) to the OA & M software. We have designed MO classes for switching-system-specific devices with a redundant configuration that ensures highly reliable system operation. The feasibility of these techniques have been confirmed on a prototype system.

To apply network monitoring functions to emerging high-quality video streaming services, we proposed an application-coexistent monitor (APCM). In APCM, a streaming server can works as an active monitor and a passive monitor. In addition, IP packets sent from the server carry monitoring information together with application's data such as video signals. To achieve APCM on a 10-Gbps network, we developed a network interface card for an application-coexistent wire-rate network monitor (AWING NIC). It provides (1) a function to append GPS-based accurate timestamps to every packet that streaming applications send and receive, which can be used for real-time monitoring of delays and inter-packet gap, and (2) functions to capture and generate 10-Gbps wire-rate traffic without depending on packets' size, achieved by our highly-efficient DMA-transfer mechanisms. Such monitoring capability are unprecedented in existing PC-based systems because of the limitation in PC system's architecture. As an evaluation of APCM in an actual network, we conducted an experiment to transmit a 6-Gbps high-quality video stream over an IP network with the system in which we installed the AWING NIC. The results revealed that the video stream became highly bursty by passing through the network, and the observed smallest inter-packet gap corresponds to the value of 10-Gbps wire-rate traffic, which supports the effectiveness of our development.