Ryutaro Kawamura

Self-healing ATM networks based on virtual path concept

This paper proposes self-healing network techniques suitable for ATM networks in order to realize a high-reliablity B-ISDN. First, the characteristics of the virtual paths (VP) and their influence on failure restoration are discussed. A high-speed restoration technique which exploits the benefits of the VP is then proposed and described. The technique simplifies the message transmission processes and reduces the number of generated messages by using preassigned backup virtual paths. Next, the scheme used to design the backup VP routes and spare resource distribution for each link is proposed in order to create a network that applies the proposed restoration scheme. Next, self-reconstruction techniques of backup virtual paths are proposed for the realization of a reversionless restoration cycle. Finally, the feasibility of the distributed control operation is discussed. >

Implementation of self-healing function in ATM networks based on virtual path concept

This paper proposes an implementation scheme for the self-healing function in ATM networks and assesses its performance. First, our proposed ATM self-healing scheme is described. This scheme realizes more rapid restoration of failed virtual paths than other self-healing algorithms, supports the node failure case, and minimizes the spare resources required. Next, an implementation scheme is proposed. We propose that the self-healing function be implemented as a software process, and that OAM cells are utilized for fast message transmission. Next, results of a prototype system that we implemented on an ATM cross-connect system are discussed. The fundamental characteristics of restoration performance are measured using an experimental network. Based on these results, an NE processing system analysis and computer simulation for estimating the characteristics as applied to a real-scale network are discussed. Finally, a management scheme for self-healing is proposed based on the TMN concept.

A middleware architecture for active distributed management of IP networks

We argue that a management platform for the future Internet has to be inherently distributed and programmable. This motivates us to introduce a new management architecture, named the active distributed management (ADM) architecture, which exploits the active network and mobile agent paradigms and provides the properties of distributed control and programmability inside the network. We realize the ADM architecture as a management middleware composed of several layers. In order to facilitate the development of efficient and correct programs, these layers include patterns for distributed algorithms that are typical for management applications and a set of building blocks for constructing management programs. First results of an ADM prototype system are presented.

Virtual path self-healing scheme based on multi-reliability ATM network concept

This paper proposes a new self-healing concept for ATM networks: multi-reliability self-healing. First, we show the necessity of multi-reliability self-healing in the future B-ISDN era, and propose a multi-reliability virtual path (VP) network concept achieved through multi-reliability self-healing. Next, we propose a new self-healing scheme based on the multi-reliability VP network by extending the existing self-healing scheme. Finally, evaluations confirm the effectiveness of the proposed scheme and the feasibility of multi-reliability VP networks.

Dynamic VP rearrangement in an ATM network

In this paper, we introduce a VP rearrangement scheme to realize the dynamic control of ATM network. We demonstrate its effectiveness for the transport of B-ISDN traffic which is both fluctuating and hard to predict. First, we present a strategy for the ATM network provisioning, used to manage both the logical VP network and the underlying physical transport network. We then propose a VP rearrangement scheme and discuss its performance. Lastly, we analyze the proposed scheme by simulations, and confirm that its performance, in comparison to the conventional, dynamic VP bandwidth control scheme, is superior.

Direct virtual path configuration in large-scale ATM networks

The paper presents a new ATM transport network technique that realizes the direct virtual path configuration by using path bandwidth control and the virtual path group concept. Direct virtual paths link local switches directly and enable channel set up processing to be eliminated from transit nodes. However, this configuration, which employs no toll switches, suffers from several problems such as reduced utilization of virtual path bandwidth and increased difficulty of localized network management based on network segmentation. The authors introduce virtual path bandwidth control and the virtual path group concept into ATM transport networks to realize the direct virtual path configuration in a very efficient manner. Virtual path bandwidth control enables the optimum balance between switching and transmission systems to be struck. Virtual path groups make it possible to provide a localized network management capability in a way similar to that available in a conventional network.<<ETX>>

Implementation of self-healing function in ATM networks

This paper proposes an implementation scheme for the self-healing function in ATM (Asynchronous Transfer Mode) networks and assesses its performance in a developed experimental system. First, our proposed ATM self-healing scheme is described. This scheme realizes more rapid restoration of failed Virtual Paths than other self-healing algorithms, supports the node failure case, and minimizes the spare resources required. Next, an implementation scheme is proposed. We propose that the self-healing function can be implemented as a software process, and that OAM (Operation, Administration, and Maintenance) cells be utilized for fast message transmission. Next, results of a prototype system that we implemented on an ATM cross-connect system are discussed. The fundamental characteristics of restoration performance are measured using the experimental system. Based on these results, restoration characteristics of real world scale networks are estimated by computer simulations. The simulation results indicate that any-one link failure is completely restored within 2 seconds.

Implementation of a distributed network middleware "CSC" on OSGi frameworks

To make communication a comfortable experience for users, we have developed a middleware called communication service concierge (CSC). This is a network middleware for distributed environments, and it consists of communication resource management (CRM) and communication logic management (CLM). Communication service concierge realizes comfortable communications by combining CRM and CLM. Communication logic management provides a framework to directly operate communication data. Communication resource management provides a framework on which downloadable software components can be executed on distributed platforms, and plays a primary role in controlling CSCs communication. Using Java, we implemented CRM on OSGi service platforms, which provide dynamic executions of the software components locally. In other words, CRM provides a distributed agent computing feature for OSGi. In this paper we describe the roles and implementations of CRM1 especially for security functions, as well as describing how CRMs software components work cooperatively.

The value centric information and intelligence sharing scheme

The information in the network has been increasing, and it is dominated by a few heavy users. This imbalance is an insignificant problem if there is an abundance of network resources. Unfortunately, the available resources are not infinite. Thus we have to develop a future network architecture that considers resource starvation. We present Value-Centric Networking (VCN) which is based on Information Value. The main purpose of VCN is to maximize Information Value in the network, and thus support the entire society. We implement the VCN architecture concept in the form of a proxy server and confirmed that VCN operation forwarded the high information value streams passing through the proxy server faster than ordinary FIFO operation. In addition, we discuss the controversial issues of VCN, value definition and feasibility.