Mitsuru Maruyama

Detection and diagnosis of Inter-AS routing anomalies by cooperative intelligent agents

Verifying whether the routing information originating from an AS is being correctly distributed throughout the Internet is important for stable inter-AS routing operation. However, the global behavior of routing information is difficult to understand because it changes spatially and temporally. Thus, rapid detection of inter-AS routing failures and diagnosis of their causes are also difficult. We have developed a multi-agent-based diagnostic system, ENCORE, to cope with these problems, and improved its functions (ENCORE-2) through our experience in applying the system to commercial ISPs. Cooperative actions among ENCORE-2 agents provide efficient methods for collecting, integrating, and analyzing routing information observed in multiple ASes to detect and diagnose anomalies that human operators have difficulty in handling. ENCORE-2 is also applied to the hijacked route problem, which is one of recent major inter-AS issues.

Parallelization of IP-packet filter rules

A compiler for parallelizing IP-packet filter rules is presented which will improve network security and reduce packet-forwarding performance degradation. It analyzes the interdependence of packet-filtering rules specified by a network administrator and translates them into an intermediate program whose instructions can be executed in parallel. Three types of compiler operations are introduced: division is used to divide the rules into parallel expressions, simplification is used to simplify redundant rules, deletion is used to delete infeasible rules.

Application-network collaborative bandwidth on-demand for uncompressed HDTV transmission in IP-optical networks

In this paper, we present an architecture design of application-network collaborative bandwidth on-demand (BoD) network service. For emerging ultra-high-bandwidth data transmission, such as HDTV streaming and Tera-byte class remote file transfer, network providers are expected to offer flexible use of the high performance of the optical network resources. This paper addresses the uncompressed HDTV transmission as the application, IP-optical networking as the network control, and the collaboration interface of those designed in order to enable three different types of network allocation: immediate BoD, reservation for future bandwidth, and planned bandwidth reservation for file transfer. Experimental deployment and the results are also shown.

Real-time processing method for an ultra high-speed streaming server running PC Linux

Integration of a high-resolution video (such as HDTV) delivery system for IP networks with legacy DBMSs and WWW systems, would make it easy to achieve system for a remote video editing, remote education and digital cinema. For this reason, we have developed a streaming server for IP networks is based on the MAPOS link-layer protocol and has a 2.48-Gbps line speed. The MAPOS protocol enables IP networks over SONET/SDH. The streaming server is constructed on a typical PC with Linux. Choosing a PC and Linux provides high performance at low cost to users. Real-time processing is important if we are to send video data at a specified rate. To implement a streaming server that can deliver Gbps video streams, we developed a real-time processing method specifically for this platform. Consequently, we obtained real-time performance for a streaming server in which the method was implemented. To evaluate its performance, we measured the receiving rate and jitter on receiving terminal while the server was delivering video streams at rates from 1.5 to 2.4 Gbps. The jitter indicates the receive-buffer size that is required and the initial delay which should be inserted before playback. For video delivery at 1.5 Gbps, the maximum buffer size was shown to be 936 KBytes (5.1 msec) and initial delay was 3.0 msec. These results show the practicability of constructing a system for ultra high-speed video (including 1.5-Gbps uncompressed HDTV) delivery with a very short response time within one video frame.

Study on Multi-path Transmission Model Based on P2P Overlay Networks for Streaming Data

In the past years, the ALM (Application Layer Multicast) has led the rapid development of the real-time streaming data transmission technology. However, as focusing on the global performance and control, the individual efficiency in the ALM structure could not be guaranteed. Furthermore, according to the complex environment of the existing networks, the available bandwidth is often made full use of. Because of these, we started this research focusing on the single efficiency, targeting a reliable end-to-end streaming data transmission model to enhance the using of the bandwidth. Keeping the virtue of high scalability and reliability, we still consider applying the P2P overlay technology as ALM. The basic idea of our research is utilizing the transmission ability of free peers in the overlay network, constructing the multiple transmitting paths from the sender to the receiver. Our multiple paths method is enabled by the overlay P2P network structure called a management network. Besides, the robustness and recovery cost are also considered in our evaluation.

Agents support for flexible Inter-AS policy control

Inter-AS routing is difficult to control since advertised inter-AS routing information changes as it spreads through ASs that are managed based on each policy. For operating the Internet reliably as we intend, we propose a flexible and autonomous policy control environment called AISLE. AISLE uses cooperative actions among distributed agents to know and control inter-AS routing behavior. This paper describes the AISLE model and architecture that enable policy control at the inter-AS level.

An UHD video handling system using a scalable server over an IP network

Ultra-high definition (UHD) videos, such as 4K and 8K, have four times higher resolution than current HDTV videos. Broadcasting stations want to deliver these videos with as little loss as possible. However, uncompressed UHD video handling systems, such as storage and transmission systems, on IP networks are not available. We researched and developed a scalable high-speed video server system to store and deliver HD or 4K videos without compression by adapting a PC cluster technology. To handle videos with higher resolution than 4K, we also developed a method that synchronises with multiple the servers and 4K video transmission systems. We achieved 54 Gbit/s delivery performance with single cluster server comprising 24 PCs. We also implemented the synchronisation method on the server and QG-70 video transmission system. As a result, we were able to demonstrate the worlds first bi-directional, real-time, uncompressed 8K-video transmission system and the 8K video-on-demand system.

A dynamic flow control mechanism based on a hierarchical feedback model for data center networks

Many studies have focused on developing Transmission Control Protocol (TCP) flow control mechanisms to enable more effective use of bandwidth in data center networks. However, the studies cannot achieve total optimization of bandwidth use for data center networks. This is because they do not take into account the path design of TCP flows and the hierarchical structure in data center networks through which TCP flows. To address this issue, we propose a TCP flow control mechanism for effectively using bandwidth by dynamically controlling paths through which TCP flows. To achieve this dynamic control, a hierarchical feedback model is used to obtain an optimal path establishment policy. With the model, all network components exchange their resource states with each other when each network component establishes a TCP flow. This enables each network component to learn the best TCP flow path for effective bandwidth use. An evaluation process shows that the mechanism achieves more effective bandwidth use and more efficient flow control than the conventional TCP flow control.

10-Gbps IP Network Measurement System Based on Application-Generated Packets Using Hardware Assistance and Off-the-Shelf PC

Targeting high-bandwidth applications such as video streaming services, we discuss advanced measurement systems for high-speed 10-Gbps networks. To verify service stability in such high-speed networks, we need to detect network quality under real environmental conditions. For example, test traffic injected into networks under-test for measurements should have the same complex characteristics as the video streaming traffic. For such measurements, we have built Internet protocol (IP) stream measurement systems by using our 10-Gbps network interface card with hardware-assisted active/passive monitor extensions based on low-cost off-the-shelf personal computers (PCs). After showing hardware requirements and our implementation of each hardware-assisted extensions, we report how we build pre-service and in-service network measurement systems to verify the feasibility of our hardware architecture. A traffic-playback system captures packets and stores traffic characteristics data without sampling any packets and then sends them precisely emulating the complex characteristics of the original traffic by using our hardware assistance. The generated traffic is useful as test traffic in pre-service measurement. A distributed in-service network monitoring system collects traffic characteristics at multiple sites by utilizing synchronized precise timestamps embedded in video streaming traffic. The results are presented on the operators display. We report on their effectiveness by measuring 1.5-Gbps uncompressed high-definition television traffic flowing in the high-speed testbed IP network in Japan.

Design and Evaluation of Application-Cooperative Bandwidth On-Demand Network with Dynamic Reconfiguration for Gbps-Class HDTV Transmission

An application-cooperative bandwidth on-demand (BoD) network with dynamic adaptive reconfiguration for Gbps-class HDTV transmission applications is presented. For high-bandwidth data transmission, such as HDTV streaming and Tera-byte-class file transfer, the strong application-network cooperation is one of the key components for facilitating stable and high-performance transmission. The BoD network offers flexible use of high performance IP/optical network resource upon application request and dynamic reconfiguration functionality in response to changes in traffic demands. This paper addresses Gbps-class HDTV transmission over a BoD network based on IP-optical networking, which uses PCE/VMTN architecture for network control, in order to examine application-network cooperation. The design of the BoD network service and its cooperation scheme for HDTV transmission are described. Performance evaluation results and issues of the BoD network and video transmission systems are shown