Application of overlay techniques to network monitoring

Measurement and monitoring are important for correct and efficient operation of a network, since these activities provide reliable information and accurate analysis for characterizing and troubleshooting a network’s performance. The focus of network measurement is to measure the volume and types of traffic on a particular network and to record the raw measurement results. The focus of network monitoring is to initiate measurement tasks, collect raw measurement results, and report aggregated outcomes. Network systems are continuously evolving: besides incremental change to accommodate new devices, more drastic changes occur to accommodate new applications, such as overlay-based content delivery networks. As a consequence, a network can experience significant increases in size and significant levels of long-range, coordinated, distributed activity; furthermore, heterogeneous network technologies, services and applications coexist and interact. Reliance upon traditional, point-to-point, ad hoc measurements to manage such networks is becoming increasingly tenuous. In particular, correlated, simultaneous 1-way measurements are needed, as is the ability to access measurement information stored throughout the network of interest. To address these new challenges, this dissertation proposes OverMon, a new paradigm for edge-to-edge network monitoring systems through the application of overlay techniques. Of particular interest, the problem of significant network overheads caused by normal overlay network techniques has been addressed by constructing overlay networks with topology awareness - the network topology information is derived from interior gateway protocol (IGP) traffic, i.e. OSPF traffic, thus eliminating all overlay maintenance network overhead. Through a prototype that uses overlays to initiate measurement tasks and to retrieve measurement results, systematic evaluation has been conducted to demonstrate the feasibility and functionality of OverMon. The measurement results show that OverMon achieves good performance in scalability, flexibility and extensibility, which are important in addressing the new challenges arising from network system evolution. This work, therefore, contributes an innovative approach of applying overly techniques to solve realistic network monitoring problems, and provides valuable first hand experience in building and evaluating such a distributed system

Blockchain technology in agri-food value chain management: A synthesis of applications, challenges and future research directions

Agri-food value chain is an area of significant importance because of providing sustainable, affordable, safety and sufficient food, feed, fibre and fuel to consumers, it is critical to ensure these value chains running smoothly and successfully by applying advanced internet technologies. Blockchain technology is a new digital technological approach underpinned by the Industry 4.0 to ensuring data integrity and preventing tampering and single point failure through offering fault-tolerance, immutability, trust, transparency and full traceability of the stored transaction records to all agri-food value chain partners. This paper used systematic literature network analysis to review the state-of-the-art blockchain technology including its recent advances, main applications in agri-food value chain and challenges from a holistic perspective. The findings suggest that blockchain technology together with advanced information and communication technology and internet of things have been adopted for the improvement of agri-food value chain management in four main aspects: traceability, information security, manufacturing and sustainable water management. Six challenges have been identified including storage capacity and scalability, privacy leakage, high cost and regulation problem, throughput and latency issue, and lack of skills. Based on the critical analysis of literature, research gaps and future research directions are proposed in this paper regarding the applications and challenges of blockchain technology in agri-food value chain management. This study makes contributions to the extant literature in the field of agri-food value chain management by discovering the potential of blockchain technology and its implications for agri-food value chain performance improvements such as food safety, food quality and food traceability

Guidelines and infrastructure for the design and implementation of highly adaptive, context-aware, mobile, peer-to-peer systems

Through a thorough review of existing literature, and extensive study of two large ubicomp systems, problems are identified with current mobile design practices, infrastructures and a lack of required software. From these problems, a set of guidelines for the design of mobile, peer-to-peer, context-aware systems are derived. Four key items of software infrastructure that are desirable but currently unavailable for mobile systems are identified. Each of these items of software are subsequently implemented, and the thesis describes each one, and at least one system in which each was used and trialled. These four items of mobile software infrastructure are: An 802.11 wireless driver that is capable of automatically switching between ad hoc and infrastructure networks when appropriate, combined with a peer discovery mechanism that can be used to identify peers and the services running and available on them. A hybrid positioning system that combines GPS, 802.11 and GSM positioning techniques to deliver location information that is almost constantly available, and can collect further 802.11 and GSM node samples during normal use of the system. A distributed recommendation system that, in addition to providing standard recommendations, can determine the relevance of data stored on the mobile device. This information is used by the same system to prioritise data when exchanging information with peers and to determine data that may be culled when the system is low on storage space without greatly affecting overall system performance. An infrastructure for creating highly adaptive, context-aware mobile applications. The Domino infrastructure allows software functionality to be recommended, exchanged between peers, installed, and executed, at runtime

NanoPeer networks and P2P worlds

We present the NanoPeers architecture paradigm, a peer-to-peer network of lightweight devices, lacking all or most of the capabilities of their computer-world counter-parts. We identify the problems arising when we apply cur-rent routing and searching methods to this nano-world, and present some initial solutions, using a case study of a sen-sor network instance; Smart Dust. Furthermore, we pro-pose the P2P Worlds framework as a hybrid P2P archi-tecture paradigm, consisting of cooperating layers of P2P networks, populated by computing entities with escalating capabilities. Our position is that (i) experience gained through research and experimentation in the field of P2P computing, can be indispensable when moving down the stair of computing capabilities, and that (ii) the proposed framework can be the basis of numerous real-world appli-cations, opening up several challenging research problems.