699 research outputs found
QoS-aware architectures, technologies, and middleware for the cloud continuum
The recent trend of moving Cloud Computing capabilities to the Edge of the network is reshaping how applications and their middleware supports are designed, deployed, and operated. This new model envisions a continuum of virtual resources between the traditional cloud and the network edge, which is potentially more suitable to meet the heterogeneous Quality of Service (QoS) requirements of diverse application domains and next-generation applications. Several classes of advanced Internet of Things (IoT) applications, e.g., in the industrial manufacturing domain, are expected to serve a wide range of applications with heterogeneous QoS requirements and call for QoS management systems to guarantee/control performance indicators, even in the presence of real-world factors such as limited bandwidth and concurrent virtual resource utilization. The present dissertation proposes a comprehensive QoS-aware architecture that addresses the challenges of integrating cloud infrastructure with edge nodes in IoT applications. The architecture provides end-to-end QoS support by incorporating several components for managing physical and virtual resources. The proposed architecture features: i) a multilevel middleware for resolving the convergence between Operational Technology (OT) and Information Technology (IT), ii) an end-to-end QoS management approach compliant with the Time-Sensitive Networking (TSN) standard, iii) new approaches for virtualized network environments, such as running TSN-based applications under Ultra-low Latency (ULL) constraints in virtual and 5G environments, and iv) an accelerated and deterministic container overlay network architecture. Additionally, the QoS-aware architecture includes two novel middlewares: i) a middleware that transparently integrates multiple acceleration technologies in heterogeneous Edge contexts and ii) a QoS-aware middleware for Serverless platforms that leverages coordination of various QoS mechanisms and virtualized Function-as-a-Service (FaaS) invocation stack to manage end-to-end QoS metrics. Finally, all architecture components were tested and evaluated by leveraging realistic testbeds, demonstrating the efficacy of the proposed solutions
Resilient and Scalable Forwarding for Software-Defined Networks with P4-Programmable Switches
Traditional networking devices support only fixed features and limited configurability.
Network softwarization leverages programmable software and hardware platforms to remove those limitations.
In this context the concept of programmable data planes allows directly to program the packet processing pipeline of networking devices and create custom control plane algorithms.
This flexibility enables the design of novel networking mechanisms where the status quo struggles to meet high demands of next-generation networks like 5G, Internet of Things, cloud computing, and industry 4.0.
P4 is the most popular technology to implement programmable data planes.
However, programmable data planes, and in particular, the P4 technology, emerged only recently.
Thus, P4 support for some well-established networking concepts is still lacking and several issues remain unsolved due to the different characteristics of programmable data planes in comparison to traditional networking.
The research of this thesis focuses on two open issues of programmable data planes.
First, it develops resilient and efficient forwarding mechanisms for the P4 data plane as there are no satisfying state of the art best practices yet.
Second, it enables BIER in high-performance P4 data planes.
BIER is a novel, scalable, and efficient transport mechanism for IP multicast traffic which has only very limited support of high-performance forwarding platforms yet.
The main results of this thesis are published as 8 peer-reviewed and one post-publication peer-reviewed publication. The results cover the development of suitable resilience mechanisms for P4 data planes, the development and implementation of resilient BIER forwarding in P4, and the extensive evaluations of all developed and implemented mechanisms. Furthermore, the results contain a comprehensive P4 literature study.
Two more peer-reviewed papers contain additional content that is not directly related to the main results.
They implement congestion avoidance mechanisms in P4 and develop a scheduling concept to find cost-optimized load schedules based on day-ahead forecasts
Path Protection Switching in Information Centric Networks (ICN)
Since its formation, the Internet has experienced tremendous growth, constantly increasing traffic and new applications, including voice and video. However, it still keeps its original architecture drafted almost 40 years ago built on the end-to-end principle; this has proven to be problematic when there are failures as routing convergence is slow for unicast networks and even slower for multicast which has to rely upon slow multicast routing as no protection switching exists for multicast. This thesis investigates protection in an alternative approach for network communication, namely information centric networking (ICN) using the architecture proposed by the PSIRP/PURSUIT projects. This uses Bloom Filters to allow both unicast and multicast forwarding. However, the PSIRP/PURSUIT ICN approach did not investigate protection switching and this problem forms the main aim of this thesis. The work builds on the research by Grover and Stamatelakis who introduced the concept of pre-configured protection p-cycles in 2000 for optical networks and, with modification, applicable to unicast IP or packet networks. This thesis shows how the p-cycle concept can be directly applied to packet networks that use PSIRP/PURSUIT ICN and extends the approach to encompass both unicast and multicast protection switching. Furthermore, it shows how the chosen p-cycles can be optimised to reduce the redundancy overhead introduced by the protection mechanism. The work evaluates the approach from two aspects, the first is how the proposed approach compares to existing switching state and traffic in an MPLS multicast architecture. The second considers the redundancy overhead in three known network topologies for synthetic traffic matrices. The thesis is the first work to demonstrate the efficiency of Bloom filter based switching for multicast (and unicast) protection switching
Internet-of-Things Streaming over Realtime Transport Protocol : A reusablility-oriented approach to enable IoT Streaming
The Internet of Things (IoT) as a group of technologies is gaining momentum to become a prominent factor for novel applications. The existence of high computing capability and the vast amount of IoT devices can be observed in the market today. However, transport protocols are also required to bridge these two advantages.
This thesis discussed the delivery of IoT through the lens of a few selected streaming protocols, which are Realtime Transport Protocol(RTP) and its cooperatives like RTP Control Protocol(RTCP) and Session Initiation Protocol (SIP). These protocols support multimedia content transfer with a heavy-stream characteristic requirement.
The main contribution of this work was the multi-layer reusability schema for IoT streaming over RTP. IoT streaming as a new concept was defined, and its characteristics were introduced to clarify its requirements. After that, the RTP stacks and their commercial implementation-VoLTE(Voice over LTE) were investigated to collect technical insights. Based on this distilled knowledge, the application areas for IoT usage and the adopting methods were described.
In addition to the realization, prototypes were made to be a proof of concept for streaming IoT data with RTP functionalities on distanced devices. These prototypes proved the possibility of applying the same duo-plane architect (signaling/data transferring) widely used in RTP implementation for multimedia services. Following a standard IETF, this implementation is a minimal example of adopting an existing standard for IoT streaming applications
Point-to-Multipoint Services on Fifth-Generation Mobile Networks
[ES] Esta disertación cubre el estado del arte en LTE eMBMS Release 14, también conocido como Enhanced Television Services (ENTV). ENTV trajo un conjunto de mejoras, tanto a nivel radio como a nivel de núcleo, que transformó a eMBMS en un estándar de televisión terrestre completo. La última versión de esta tecnologÃa se denomina LTE-based 5G Broadcast; pero no usa New Radio ni el núcleo 5G. Para proveer una solución nativa 5G de servicios punto-a-multipunto, hubo investigación en entornos acad\'emicos y colaboraciones público-privada. La iniciativa más notable en este aspecto fue el proyecto del Horizon 2020 5G-Xcast, que transcurrió de 2017 a 2019. 5G-Xcast produjo varias soluciones a nivel de arquitectura, desde la perspectiva de provisión de contenidos, nuevas funciones de red interoperables con el núcleo 5G, hasta modificaciones a la interfaz aire basada en New Radio. Los hallazgos del proyecto están descritos en esta tesis. La tesis incluye dos ejemplos de eMBMS aplicados a verticales diferentes, una para el uso de eMBMS en entornos industriales, y otra presentando eMBMS como un sistema SAP.
Incluir servicios punto-a-multipunto como un modo adicional celular trae algunos desafÃos, como ya mostró la estandarización de eMBMS: las redes de radiodifusión terrestre y las redes celulares son muy distintas entre ellas. Encontrar una forma de onda viable para ambas infraestructuras es complejo. Esta tesis ofrece un punto de vista distinto al problema: un escenario de colaboración entre cadenas televisivas y operadores móviles, donde la infraestructura de radiodifusión y móvil son compartidas. Este concepto se ha definido como Convergence of Terrestrial and Mobile Networks. Las tecnologÃas elegidas para converger son ATSC 3.0 y 5G, usando el Advanced Traffic Steering, Switching and Splitting (ATSSS). ATSSS está compuesto de una serie de procedimientos, interfaces, funciones de red, para permitir el uso compartido de un acceso 3GPP con uno non-3GPP, como Wi-Fi. Sin embargo, el uso de ATSSS para juntar radiodifusión y celular no es trivial, ya que ATSSS no fue dise\~{n}ado para enlaces radio unidireccionales como ATSC 3.0. Estas limitaciones son descritas en detalle, y una propuesta para solventarlas tambi\'en está incluida. La solución se basa en Quick UDP Internet Connections (QUIC), y se usa como ejemplo para la provisión de Convergent Services (File Repair y Video Offloading).
La tesis concluye con una descripción de Release 17 5MBS, con los nuevos conceptos introducidos. 5MBS es capaz de cambiar entre unicast, multicast y broadcast; dependiendo del servicio, la ubicación geográfica de los usuarios, y las capacidades de la infraestructura móvil involucradas. Para evaluar 5MBS, se ha realizado un estudio de prestaciones, basado en comunicaciones multicast dentro del núcleo de red 5G. Este prototipo 5MBS forma parte del laboratorio VLC Campus 5G, y utiliza el software comercial Open5GCore como base del desarrollo. El modelo de sistema para la experimentación esta formado por un servidor de vÃdeo, que se conecta al Open5GCore y a las funciones de red mejoradas con funcionalidades 5MBS. Estas funciones de red envÃan el contenido mediante punto-a-multipunto a un entorno radio y terminales simulados. Los resultados obtenidos resaltan el objetivo principal de la tesis: las comunicaciones punto-a-multipunto son una solución escalable para el envÃo de contenido multimedia en directo.[CA] Aquesta dissertació cobreix capdavanter en LTE eMBMS Release 14, també
conegut com Enhanced Television Services (ENTV). ENTV va portar un conjunt
de millores, tant a nivell de rà dio com a nivell de nucli, que va transformar el eMBMS en un està ndard de televisió terrestre complet. La última
versió d'aquesta tecnologia es denomina LTE-based 5G Broadcast; però no fa servir
New Rà dio ni el nucli 5G. Per a proveir una solució nativa 5G de serveis punt-a-multipunt, va haver-hi investigació en entorns acadèmics i col·laboracions
pública i privada. La iniciativa més notable en aquest aspecte va ser el projecte
del Horizon 2020 5G-Xcast, que va transcórrer del 2017 a 2019. 5G-Xcast va produir
diverses solucions a nivell d'arquitectura, des de la perspectiva de provisió de
continguts, noves funcions de xarxa interoperables amb el nucli 5G, fins a modificacions
a la interfÃcie aire basada en New Radio. Les troballes del projecte
estan descrits en aquesta tesi. La tesi inclou dos exemples de eMBMS aplicats
a verticals diferents, una per a l'ús de eMBMS en entorns industrials, i
una altra presentant eMBMS com un sistema SAP.
Incloure serveis punt-a-multipunt com una manera addicional cel·lular duu
alguns desafiaments, com ja va mostrar l'estandardització de eMBMS: les xarxes de
radiodifusió terrestre i les xarxes cel·lulars són molt diferents entre elles. Trobar
una forma d'ona viable per a totes dues infraestructures és complex.
Aquesta tesi ofereix un punt de vista diferent al problema: un escenari de col·laboració entre cadenes televisives i operadors mòbils, on la infraestructura
de radiodifusió i mòbil són compartides. Aquest concepte s'ha definit com
Convergence of Terrestrial and Mobile Networks. Les tecnologies triades per a
convergir són ATSC 3.0 i 5G, usant el Advanced Traffic Steering, Switching
and Splitting (ATSSS). ATSSS està compost d'una sèrie de procediments,
interfÃcies, funcions de xarxa, per a permetre l'ús compartit d'un accés
3GPP amb un non-3GPP, com a Wi-Fi. No obstant això, l'ús de ATSSS per a
adjuntar radiodifusió i cel·lular no és trivial, ja que ATSSS no va ser dissenyada
per a per a enllaços rà dio unidireccionals com ATSC 3.0. Aquestes limitacions són
descrites detalladament, i una proposta per a solucionar-les també està inclosa.
La solució es basa en Quick UDP Internet Connections (QUIC), i s'usa
com a exemple per a la provisió de Convergent Services (File Repair i VÃdeo
Offloading).
La tesi conclou amb una descripció de Release 17 5MBS, amb els nous
conceptes introduïts. 5MBS és capaç de canviar entre unicast, multicast i
broadcast; depenent del servei, la ubicació geogrà fica dels usuaris, i
les capacitats de la infraestructura mòbil involucrades. Per a avaluar 5MBS,
s'ha realitzat un estudi de prestacions, basat en comunicacions multicast
dins del nucli de xarxa 5G. Aquest prototip 5MBS forma part del laboratori
VLC Campus 5G, i utilitza el programari comercial Open5GCore com a base
del desenvolupament. El model de sistema per a l'experimentació està format
per un servidor de vÃdeo, que es connecta al Open5GCore i a les funcions
de xarxa millorades amb funcionalitats 5MBS. Aquestes funcions de xarxa envien el
contingut mitjançant punt-a-multipunt a un entorn rà dio i terminals simulats.
Els resultats obtinguts ressalten l'objectiu principal de la tesi: les
comunicacions punt-a-multipunt són una solució escalable per a l'enviament
de contingut multimèdia en directe.[EN] This dissertation covers the state-of-the-art in LTE eMBMS Release 14, also known as Enhanced Television Services (ENTV). ENTV provided a suite of radio and core enhancements that made eMBMS into a viable terrestrial broadcast standard. The latest iteration of this technology is known as LTE-based 5G Broadcast; even though it is not New Radio or 5G Core based. To bridge this gap, research efforts by academia, public and private enterprises evaluated how to provide a 5G-based solution for point-to-multipoint services. The most notable effort in this regard is the Horizon 2020 project 5G-Xcast, which ran from 2017 to 2019. 5G-Xcast provided several architectural solutions, from the content delivery perspective down to air interface specifics; providing new waveforms based on New Radio and Network Functions interoperable with a Release 15 5G Core. The findings are summarized in this thesis. Two examples of eMBMS applied to different verticals are included in the thesis, one for the use of eMBMS in industrial environments, and the other using eMBMS as a PWS technology.
Providing point-to-multipoint services as another cellular service poses some problems, as the standardization process of eMBMS showed: the broadcast infrastructure is different than the cellular one. Having a waveform that is suited for both scenarios is a difficult endeavour. The thesis provides a new perspective into this problem: Having existing Terrestrial Broadcast standards and infrastructure be the point-to-multipoint solution of 5G, where mobile operators and broadcasters collaborate together. This is defined in the dissertation as Convergence of Terrestrial and Mobile Networks. The technologies chosen to be converged together were ATSC 3.0 and 5G; using the existing Release 16 framework known as Advanced Traffic Steering, Switching and Splitting (ATSSS). ATSSS is a series of procedures, interfaces, new Network Functions, to allow the joint use of a 3GPP Access Network alongside a non-3GPP one, like Wi-Fi. However, the use of ATSSS for cellular plus broadcast brings challenges, as the ATSSS technology was not designed to be used with a unidirectional access network like ATSC 3.0. These limitations are described in detail, and an architectural proposal that overcomes the limitations is proposed. This solution is based on Quick UDP Internet Connections (QUIC), and how to provide Convergent Services (i.e File Repair and Video Offloading) is shown.
The thesis concludes with a description of Release 17 5MBS, including the new concepts introduced. 5MBS features the capacity of switching between unicast, multicast and broadcast; depending on the service addressed, the geographical location of the users, and the capability of the RAN infrastructure targeted. In order to evaluate 5MBS, a performance study of the use of multicast inside the 5G Core has been carried out. The 5MBS prototype was developed as part of the VLC Campus 5G laboratory, using the commercial software Open5GCore which provides the libraries and Network Functions to deploy your own 5G Private Network in testing environments. The system model of the experiment is formed by a video server, connected to the Open5GCore and the 5MBS enhanced functions; which will deliver the content to an emulated RAN environment hosting virtual gNBs and devices. The results obtained reinforce the objective of the thesis, positioning point-to-multipoint as a scalable way to deliver live content.Research projects: 5G-Xcast: Broadcast and Multicast Communication Enablers for the
Fifth-Generation of Wireless Systems (H2020 No 761498); 5G-TOURS: SmarT mObility, media and e-health for toURists and citizenS (H2020 No 856950); FUDGE-5G: FUlly DisinteGrated private nEtworks for 5G verticals (H2020 No 957242).Barjau Estevan, CS. (2022). Point-to-Multipoint Services on Fifth-Generation Mobile Networks [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/19140
SoK: Distributed Computing in ICN
Information-Centric Networking (ICN), with its data-oriented operation and
generally more powerful forwarding layer, provides an attractive platform for
distributed computing. This paper provides a systematic overview and
categorization of different distributed computing approaches in ICN
encompassing fundamental design principles, frameworks and orchestration,
protocols, enablers, and applications. We discuss current pain points in legacy
distributed computing, attractive ICN features, and how different systems use
them. This paper also provides a discussion of potential future work for
distributed computing in ICN.Comment: 10 pages, 3 figures, 1 table. Accepted by ACM ICN 202
ZeroComm: Decentralized, Secure and Trustful Group Communication
In the context of computer networks, decentralization is a network architecture that distributes
both workload and control of a system among a set of coequal participants. Applications based
on such networks enhance trust involved in communication by eliminating the external author-
ities with self-interests, including governments and tech companies. The decentralized model
delegates the ownership of data to individual users and thus mitigates undesirable behaviours
such as harvesting personal information by external organizations. Consequently, decentral-
ization has been adopted as the key feature in the next generation of the Internet model which
is known as Web 3.0. DIDComm is a set of abstract protocols which enables secure messaging
with decentralization and thus serves for the realization of Web 3.0 networks. It standardizes
and transforms existing network applications to enforce secure, trustful and decentralized com-
munication. Prior work on DIDComm has only been restricted to pair-wise communication and
hence it necessitates a feasible strategy for adapting the Web 3.0 concepts in group-oriented
networks.
Inspired by the demand for a group communication model in Web 3.0, this study presents Zero-
Comm which preserves decentralization, security and trust throughout the fundamental opera-
tions of a group such as messaging and membership management. ZeroComm is built atop the
publisher-subscriber pattern which serves as a messaging architecture for enabling communi-
cation among multiple members based on the subjects of their interests. This is realized in our
implementation through ZeroMQ, a low-level network library that facilitates the construction
of advanced and distributed messaging patterns. The proposed solution leverages DIDComm
protocols to deliver safe communication among group members at the expense of performance
and efficiency. ZeroComm offers two different modes of group communication based on the
organization of relationships among members with a compromise between performance and
security. Our quantitative analysis shows that the proposed model performs efficiently for the
messaging operation whereas joining a group is a relatively exhaustive procedure due to the es-
tablishment of secure and decentralized relationships among members. ZeroComm primarily
serves as a low-level messaging framework but can be extended with advanced features such
as message ordering, crash recovery of members and secure routing of messages
Models, methods, and tools for developing MMOG backends on commodity clouds
Online multiplayer games have grown to unprecedented scales, attracting millions of players
worldwide. The revenue from this industry has already eclipsed well-established entertainment
industries like music and films and is expected to continue its rapid growth in the future.
Massively Multiplayer Online Games (MMOGs) have also been extensively used in research
studies and education, further motivating the need to improve their development process.
The development of resource-intensive, distributed, real-time applications like MMOG backends
involves a variety of challenges. Past research has primarily focused on the development and
deployment of MMOG backends on dedicated infrastructures such as on-premise data centers
and private clouds, which provide more flexibility but are expensive and hard to set up and
maintain. A limited set of works has also focused on utilizing the Infrastructure-as-a-Service
(IaaS) layer of public clouds to deploy MMOG backends. These clouds can offer various advantages
like a lower barrier to entry, a larger set of resources, etc. but lack resource elasticity,
standardization, and focus on development effort, from which MMOG backends can greatly
benefit.
Meanwhile, other research has also focused on solving various problems related to consistency,
performance, and scalability. Despite major advancements in these areas, there is no standardized
development methodology to facilitate these features and assimilate the development of
MMOG backends on commodity clouds. This thesis is motivated by the results of a systematic
mapping study that identifies a gap in research, evident from the fact that only a handful
of studies have explored the possibility of utilizing serverless environments within commodity
clouds to host these types of backends. These studies are mostly vision papers and do
not provide any novel contributions in terms of methods of development or detailed analyses
of how such systems could be developed. Using the knowledge gathered from this mapping
study, several hypotheses are proposed and a set of technical challenges is identified, guiding
the development of a new methodology.
The peculiarities of MMOG backends have so far constrained their development and deployment
on commodity clouds despite rapid advancements in technology. To explore whether such
environments are viable options, a feasibility study is conducted with a minimalistic MMOG
prototype to evaluate a limited set of public clouds in terms of hosting MMOG backends. Foli
lowing encouraging results from this study, this thesis first motivates toward and then presents
a set of models, methods, and tools with which scalable MMOG backends can be developed
for and deployed on commodity clouds. These are encapsulated into a software development
framework called Athlos which allows software engineers to leverage the proposed development
methodology to rapidly create MMOG backend prototypes that utilize the resources of
these clouds to attain scalable states and runtimes. The proposed approach is based on a dynamic
model which aims to abstract the data requirements and relationships of many types of
MMOGs. Based on this model, several methods are outlined that aim to solve various problems
and challenges related to the development of MMOG backends, mainly in terms of performance
and scalability. Using a modular software architecture, and standardization in common development
areas, the proposed framework aims to improve and expedite the development process
leading to higher-quality MMOG backends and a lower time to market. The models and methods
proposed in this approach can be utilized through various tools during the development
lifecycle.
The proposed development framework is evaluated qualitatively and quantitatively. The thesis
presents three case study MMOG backend prototypes that validate the suitability of the proposed
approach. These case studies also provide a proof of concept and are subsequently used
to further evaluate the framework. The propositions in this thesis are assessed with respect to
the performance, scalability, development effort, and code maintainability of MMOG backends
developed using the Athlos framework, using a variety of methods such as small and large-scale
simulations and more targeted experimental setups. The results of these experiments uncover
useful information about the behavior of MMOG backends. In addition, they provide evidence
that MMOG backends developed using the proposed methodology and hosted on serverless
environments can: (a) support a very high number of simultaneous players under a given latency
threshold, (b) elastically scale both in terms of processing power and memory capacity
and (c) significantly reduce the amount of development effort. The results also show that this
methodology can accelerate the development of high-performance, distributed, real-time applications
like MMOG backends, while also exposing the limitations of Athlos in terms of code
maintainability.
Finally, the thesis provides a reflection on the research objectives, considerations on the hypotheses
and technical challenges, and outlines plans for future work in this domain
Design and implementation of an advanced MQTT broker for distributed pub/sub scenarios
MQTT is one of the most popular communication protocols for Internet of Things applications. Based on a publish/subscribe pattern, it relies on a single broker to exchange messages among clients according to topics of interest. However, such a centralized approach does not scale well and is prone to single point of failure risks, calling for solutions where multiple brokers cooperate together in a distributed fashion. In this paper, we present a complete solution for a distributed MQTT broker systems. We target several functional primitives which are key in such a scenario: broker discovery and failure recovery, overlay tree network creation and message routing. Moreover, we also focus on the case where multiple topics are present in the system. In such a scenario, a single tree-based overlay network connecting the different brokers may not be the most efficient solution. To cope with this issue, we propose a topic-based routing scheme for MQTT distributed brokers. The proposed solution creates multiple overlay networks in the distributed system, each one linking together only the brokers whose connected clients have interest in the same topics. We implement the complete system as an extension of the popular HiveMQ MQTT broker and perform several experiments to test its performance in scenarios characterized by a different publishers/subscribers configurations as well as number of topics existing in the system
Enabling Resilient and Efficient Communication for the XRP Ledger and Interledger
The blockchain technology is relatively new and still evolving. Its development was fostered by an enthusiastic community of developers, which sometimes forgot about the lessons from the past related to security, resilience and efficiency of communication which can impact network scalability, service quality and even service availability. These challenges can be addressed at network level but also at operating system level. At network level, the protocols and the architecture used play a major role, and overlays have interesting advantages like custom protocols and the possibility of arbitrary deployments. This thesis shows how overlay networks can be designed and deployed to benefit the security and performance in communication for consensus-validation based blockchains and blockchain inter-operativity, taking as concrete cases the XRP ledger and respectively the Interledger protocol. XRP Ledger is a consensus-validation based blockchain focused on payments which currently uses a flooding mechanism for peer to peer communication, with a negative impact on scalability. One of the proposed overlays is based on Named Data Networking, an Internet architecture using for propagation the data name instead of data location. The second proposed overlay is based on Spines, a solution offering improved latency on lossy paths, intrusion tolerance and resilience to routing attacks. The system component was also interesting to study, and the contribution of this thesis centers around methodologies to evaluate the system performance of a node and increase the security from the system level. The value added by the presented work can be synthesized as follows: i) investigate and propose a Named Data Networking-based overlay solution to improve the efficiency of intra-blockchain communication at network level, taking as a working case the XRP Ledger; ii) investigate and propose an overlay solution based on Spines, which improves the security and resilience of inter-blockchain communication at network level, taking as a working case the Interledger protocol; iii) investigate and propose a host-level solution for non-intrusive instrumentation and monitoring which helps improve the performance and security of inter-blockchain communication at the system level of machines running Distributed Ledger infrastructure applications treated as black-boxes, with Interledger Connectors as a concrete case
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