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Featured researches published by Masaki Umayabashi.


IEEE Journal on Selected Areas in Communications | 2004

Global open ethernet (GOE) system and its performance evaluation

Atsushi Iwata; Youichi Hidaka; Masaki Umayabashi; Nobuyuki Enomoto; Akira Arutaki

This paper presents an overview of global open Ethernet (GOE) architecture as a cost-effective Ethernet-based virtual private network (VPN) solution, and discusses a hardware and software implementation of a prototype system. Three main approaches have been proposed for a VPN solution on metro-area network: resilient packet ring, Ethernet over multiprotocol label switching (EoMPLS), virtual bridged local area network-tag stacking (Q-in-Q). None of these schemes can satisfy the following requirements at the same time: network topology flexibility, affordable network functionalities, low equipment cost, and low operational cost. The proposed GOE system is designed to solve VPN management problems of these approaches with MPLS VPN functionality at a low cost of Ethernet-based solution. The key components of GOE are: 1) a novel GOE tag for high-speed switching and 2) a novel routing and protection module via per-destination multiple rapid spanning tree protocol (PD-MRSTP). Via the analytical performance evaluation of EoMPLS, Q-in-Q, and GOE, we show that the memory cost and the network utilization of GOE is two-three times smaller and 22% higher than the other approaches, respectively. We also have developed a GOE prototype system and obtained the following remarkable hardware and software performance results. The GOE core switch delivered 100% of theoretical maximum throughput (10 G) with zero packet loss even with the field programmable gate array platform, and its 10-G port density is 1.5 times denser than the best currently available products. The GOE switch using PD-MRSTP also delivered a significantly fast protection switching time (1.975 ms), which was significantly faster than legacy Ethernet switches. These performance evaluation results prove that the proposed GOE system can be used as a cost-effective high-performance Ethernet-based VPN solution.


IEICE Transactions on Communications | 2006

Improving ethernet reliability and stability using global open ethernet technology

Masaki Umayabashi; Youichi Hidaka; Nobuyuki Enomoto; Daisaku Ogasahara; Kazuo Takagi; Atsushi Iwata; Akira Arutaki

In this paper, authors present new schemes of our proposed Global Open Ethernet (GOE) technology from a viewpoint of improving reliability in metro-area Ethernet environment and show the numerical evidence on their performance results. Although several standardized or vendor proprietary technologies are proposed to improve Ethernet reliability, they still have reliability problems in terms of long failure recovery time (due to forwarding database (FDB) flush and recovery from a root bridge failure on spanning tree protocol), broadcast storm, and packet loss in network reconfiguration. To solve these problems, we introduce three schemes, a Per Destination - Multiple Rapid Spanning Tree Protocol (PD-MRSTP), a GOE Virtual Switch Redundancy Protocol (GVSRP), and an In-Service Reconfiguration (ISR) schemes. PD-MRSTP scheme reduces the failure recovery time by eliminating the need to flush the FDB and to recover from root bridge failures. GVSRP scheme ensures the reliability of connections between a GOE domain and a legacy Ethernet domain. Combined with PD-MRSTP, GVSRP prevents broadcast storm problems due to loops in the inter-domain area. ISR scheme enables in-service bridge replacement and upgrade without packet loss. Evaluating our prototype system, we obtained the following remarkable performance results. The GOE network using PD-MRSTP scheme delivered a fast failure recovery performance (4 ms) independent of the number of MAC address entries, whereas the legacy Ethernet network took 522 ms when a bridge had 6000 MAC address entries. Since we found that the failure recovery time increased in proportion to the number of MAC address entries, the one in large carrier network having one million of MAC address entries would take several tens of seconds. Thus using PD-MRSTP can reduce failure recovery time one ten-thousandth comparing with that of legacy Ethernet. In addition, evaluation of the ISR scheme demonstrated that a network can be upgraded with zero packet loss. Therefore, a GOE-based VPN is a promising alternative to other Ethernet VPNs for its reliability and stability.


Archive | 1999

BANDWIDTH ALLOCATION SYSTEM OF VIRTUAL PATH IN COMMUNICATION NETWORK OF ASYNCHRONOUS TRANSFER MODE

Masaki Umayabashi


Archive | 2003

Network system, spanning tree configuration method, spanning tree configuration node, and spanning tree configuration program

Nobuyuki Enomoto; Masaki Umayabashi; Youichi Hidaka; Atsushi Iwata; Makoto Shibutani


Archive | 2003

Frame transfer method and node in network, and frame transfer program

Masaki Umayabashi; Kazuo Takagi; Youichi Hidaka; Nobuyuki Enomoto; Atsushi Iwata; Makoto Shibutani


Archive | 2003

Network system, learning bridge node, learning method and its program

Nobuyuki Enomoto; Youichi Hidaka; Masaki Umayabashi; Atsushi Iwata


Archive | 2003

Multiring control method, node using the method, and control program

Kazuo Takagi; Masaki Umayabashi


Archive | 2004

Network system, spanning tree configuration method and configuration program, and spanning tree configuration node

Nobuyuki Enomoto; Masaki Umayabashi; Youichi Hidaka; Atsushi Iwata


Archive | 2005

NETWORK SYSTEM, NODE, NODE CONTROL PROGRAM, AND NETWORK CONTROL METHOD

Daisaku Ogasawara; Nobuyuki Enomoto; Hajime Mizoguchi; Keiichi Sunada; Masaki Umayabashi; Youichi Hidaka; Atsushi Iwata


Archive | 2002

Packet communication system, network side device and terminal side device thereof and identifier assigning method

Masaki Umayabashi

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