Internet Core

Current Research Topics

Emulated Internet for Scalability Tests

Complexity of the physical resource assignment and numerous configurations makes it difficult for an experimenter to build an experimental network. Also, the differences of description among configuration files used on each software and hardware makes it difficult to reuse these files. In this paper, we propose the AnyBed: the experimental network building system using the logical and physical network topologies which are described in XML. Mapping these two topologies, AnyBed can build intended logical network topology on any PC clusters. We have also evaluated an implementation of AnyBed using two distinct clusters.

Overlay Network

As the Internet grows, its traditional architecture and applications have revealed some problems such as the overload on centralized servers and the existence of single points of failure. In these years, researchers are spotlighting "overlay network" as a solution against these problems. Our research focuses on QoS, security, mobility and diversity on overlay networks from both the methodological aspect and the practical aspect.

IPv6 Network Evaluation Testbed(IPv6NET)

Among the many challenges introduced by the IPv6 transition process to the Internet community, one of the most difficult was presented to the network operators. All of the existing production networks were forced to reconsider their inner architecture to move towards IPv6. To support network operators in this challenge, the IETF has proposed multiple IPv6 transition and coexistence technologies. Which one of these technologies is most feasible for their scenario, is still an open problem. To support network operators solve this problem, we are proposing a suite of practical evaluation methodologies, exploring various feasibility dimensions of transition technologies. The methodologies are associated with a heterogeneous IPv4 and IPv6 network testbed, which we called the IPv6 Network Evaluation Testbed (IPv6NET). In order to validate these methodologies, we have used them to analyze the feasibility of two open source transition implementations, covering multiple transition technologies. To that end, we are showing how network performance, scalability and operational capability data can be obtained, analyzed and compared.

Application-Oriented Measurement Platforms on the Internet

Nowadays the applications that provide large-scale services, such as overlay network applications and network monitoring across multiple networks, realize the importance of the quick and accurate grasp of the Internet state for scaling and sustaining their services. Towards the Inte rnet with "a clearer view," our research fields include cooperative network measurement methodologies, the platforms on which these methodologies are implem ented, and the analysis and visualization of measured data.

Scalable QoS mechanism for next generation VPNs

A strong demand for quality of service (QoS) of virtual private networks (VPNs) has emerge d. To meet service level agreement (SLA), QoS must be provided. We propose novel bandwidth allocation method for hose model which is scalable VPN model. To achieve QoS architecture for large-scale VPNs, characteristics of the hose bandw idth allocation method are clarified.