Extension of IPSec for Port Control

インターネットは現代社会において欠くことのできない存在となっている。最近では、外出先などからインターネットを使って安全に社内へアクセスしたり、特定のビジネスパートナーに対して安全に情報提供したりするニーズが高まっている。このようなニーズに対して専用線を用いる方法があるが、コストが高いという問題があった。インターネットを利用した場合にはコストの削減が可能であるが、データの盗聴・改ざんの危険が存在する。この両方の問題を改善するものとしてVPN (Virtual Private Network)が考えられた。VPNに使われる技術の１つにIPsecがある。本論文では、このIPsecについて、アプリケーションごとに制御できるように機能の追加を行う。修士論

Advanced Compression and Latency Reduction Techniques Over Data Networks

Applications and services operating over Internet protocol (IP) networks often suffer from high latency and packet loss rates. These problems are attributed to data congestion resulting from the lack of network resources available to support the demand. The usage of IP networks is not only increasing, but very dynamic as well. In order to alleviate the above-mentioned problems and to maintain a reasonable Quality of Service (QoS) for the end users, two novel adaptive compression techniques are proposed to reduce packets’ payload size. The proposed schemes exploit lossless compression algorithms to perform the compression process on the packets’ payloads and thus decrease the overall net- work congestion. The first adaptive compression scheme utilizes two key network performance indicators as design metrics. These metrics include the varying round-trip time (RTT) and the number of dropped packets. The second compression scheme uses other network information such as the incoming packet rate, intermediate nodes processing rate, average packet waiting time within a queue of an intermediate node, and time required to perform the compression process. The performances of the proposed algorithms are evaluated through Network Simulator 3 (NS3). The simulation results show an improvement in network conditions, such as the number of dropped packets, network latency, and throughput

REAL-TIME COMPRESSION OF SOFTWARE TRACES

Techniques are presented herein that support the compression of software-generated traces as a stream, in real time, with reduced central processing unit (CPU) overhead. Such an approach may reduce cloud hosting bandwidth charges and is relevant when moving troubleshooting information from a device into the cloud for analysis. Additionally, such an approach eliminates the bursty nature of file-based compression that is typically achieved using legacy compression utilities. As a result, the presented techniques are more amenable to small CPU footprints such as, for example, a cloud-based router having just a single CPU. Aspects of the presented techniques have a broad scope and may be applied to any software system that generates traces, which is typically all modern software systems. Further aspects of the presented techniques may potentially be applied to industry technologies (such as OpenTelemetry) that support the distributed tracing of cloud hosted applications

Web Content Delivery Optimization

Milliseconds matters, when they’re counted. If we consider the life of the universe into one single year, then on 31 December at 11:59:59.5 PM, “speed” was transportation’s concern, and now after 500 milliseconds it is web’s, and no one knows whose concern it would be in coming milliseconds, but at this very moment; this thesis proposes an optimization method, mainly for content delivery on slow connections. The method utilizes a proxy as a middle box to fetch the content; requested by a client, from a single or multiple web servers, and bundles all of the fetched image content types that fits into the bundling policy; inside a JavaScript file in Base64 format. This optimization method reduces the number of HTTP requests between the client and multiple web servers as a result of its proposed bundling solution, and at the same time optimizes the HTTP compression efficiency as a result of its proposed method of aggregative textual content compression. Page loading time results of the test web pages; which were specially designed and developed to capture the optimum benefits of the proposed method; proved up to 81% faster page loading time for all connection types. However, other tests in non-optimal situations such as webpages which use “Lazy Loading” techniques, showed just 35% to 50% benefits, that is only achievable on 2G and 3G connections (0.2 Mbps – 15 Mbps downlink) and not faster connections

LOW LATENCY ON-BOARD DATA HANDLING FOR EARTH OBSERVATION SATELLITES USING OFF-THE-SHELF COMPONENTS

Satellite Earth Observation (EO) is nowadays receiving significant attention. In this regard, the latency of EO product provision to the ground segment is undoubtedly among the first key performance indicators for these systems. The European Union Horizon 2020 EO-ALERT project aims at overcoming the limitations of traditional Near Real-Time (NRT) onboard data chain architectures by moving all the critical processing tasks on the flight segment and accelerating them using high-performance commercial off-the-shelf (COTS) devices. The resulting architecture minimizes the amount of transmitted data and eliminates ground-based data processing from the EO data chain, hence achieving actual real-time product delivery in less than 5 min with optical and Synthetic Aperture Radar (SAR) data. This paper presents the performance benefits of a mixed software-hardware design of the CPU Scheduling, Compression, Encryption, and Data Handling (CS-CEDH) Subsystem responsible for data compression and encryption as well as data routing and scheduling tasks. Compared to a software-only solution, the exploited High-Level Synthesis (HLS) methodology enables 5 to 7-fold speed-up in onboard image compression and encryption tasks and 2 to 5-fold reduction in the contribution of the CS-CEDH Subsystem to the overall onboard image data chain while contributing by less than 1 s to the delivery of the alerts to the end-user