Exploring potential implementations of PCE in IoT world

© . This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/The recently coined Internet of Things (IoT) paradigm leverages a large volume of heterogeneous Network Elements (NEs) demanding broad connectivity anywhere, anytime and anyhow, fueling the deployment of innovative Internet services, such as Cloud or Fog Computing, Data Center Networks (DCNs), Smart Cities or Smart Transportation. The proper deployment of these novel Internet services is imposing hard connectivity constraints, such as high transmission capacity, reliable communications, as well as an efficient control scheme capable of enabling an agile coordination of actions in large heterogeneous scenarios. In recent years, novel control schemes, such as the so-called Path Computation Element (PCE) has gained momentum in the network research community turning into real PCE implementations. Indeed, there is a wealth of studies assessing the PCE performance, clearly showing the potential benefits of decoupling routing control tasks from the forwarding nodes. Nevertheless, recognized the need for a control solution in IoT scenarios, there is not much published information analyzing PCE benefits in these IoT scenarios. In this paper, we distill how the PCE may gracefully provide for service composition in an agile manner, handling the specific constraints and requirements found in IoT scenarios. To this end, we propose a novel PCE strategy referred to as Service-Oriented PCE (SPCE), which enables network-aware service composition.Peer ReviewedPostprint (author's final draft

A novel predictive PCE-based protection strategy for resilient transport networks

© 2016. The ever increasing requirements of new Internet applications are pushing to optimize the design of optical networks. A key design criterion in network design is the ability to recover from failures in an agile and efficient manner. Protection capabilities are highly required in optical networks since the failure of an optical link might potentially lead to a significant traffic loss. Under this context, Network Coding Protection (NCP) has emerged as an innovative solution to proactively enable protection in an agile and efficient manner by means of throughput improvement techniques such as Network Coding (NC). Nevertheless, the benefits of NC can be reduced by the negative effects of inaccurate Network State Information (NSI), which are common in dynamic scenarios.In this paper, we propose a novel proactive protection strategy based on NC jointly with a Path Computation Element (PCE) architecture called Predictive Network Coding Protection (PNCP). PNCP leverages predictive techniques in order to mitigate the negative impact of the inaccurate NSI on the blocking probability. In addition, PNCP computes resilient lightpaths with a low amount of network resources devoted for path protection.By means of extensive simulation results we show that in comparison with proactive protection strategies such as Dedicated Path Protection (DPP), and conventional dynamic NCP, PNCP reduces the blocking probability as well as the network resources allocated for path protection in dynamic scenarios.Postprint (author's final draft

Toward a new addressing scheme for a service-centric Internet

© 2012 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Traditional network architectures based on the Internet Protocol (IP) are now being questioned by the research community, since they are no longer positioned as the most suitable paradigm for supporting the increasing diversity of applications and uses of the Internet. A key issue in this subject is that, although the IP protocol has provided the basis for the rapid evolution of the Internet, its addressing scheme is not prepared to face the challenges posed by many foreseen applications. In light of this, different initiatives worldwide have started specific research programs to address these problems and work toward the "Future Internet". The TARIFA project represents one of these initiatives, and it is positioned as a clean slate alternative aimed at overcoming the critical issues in today's Internet. The novelty in TARIFA resides in the fact that any “commodity” in the network can be composed as a set of atomic services, which can be in turn assembled through a service-centric model for building a promising Internet architecture. In this paper, we focus on the space requirements and set the basis for a new addressing scheme suitable for service-centric network architectures such as the one proposed by TARIFA. The addressing scheme discussed in this paper is general in scope, and could be applied not only to architectures based on the composition of services but also to user and data-centric Internet architectures.This work was supported in part by the TARIFA project, by the Spanish Ministry of Science and Innovation under contract TEC2009-07041, and by the Catalan Research Council (CIRIT) under contract 2009 SGR1508.Postprint (author's final draft

Evaluating the benefits of combined and continuous Fog-to-Cloud architectures

The need to extend the features of Cloud computing to the edge of the network has fueled the development of new computing architectures, such as Fog computing. When put together, the combined and continuous use of fog and cloud computing, lays the foundation for a new and highly heterogeneous computing ecosystem, making the most out of both, cloud and fog. Incipient research efforts are devoted to propose a management architecture to properly manage such combination of resources, such as the reference architecture proposed by the OpenFog Consortium or the recent Fog-to-Cloud (F2C). In this paper, we pay attention to such a combined ecosystem and particularly evaluate the potential benefits of F2C in dynamic scenarios, considering computing resources mobility and different traffic patterns. By means of extensive simulations we specifically study the aspects of service response time, network bandwidth occupancy, power consumption and service disruption probability. The results indicate that a combined fog-to-cloud architecture brings significant performance benefits in comparison with the traditional standalone Cloud, e.g., over 50% reduction in terms of power consumption.Preprin

Improving reliability in multi-layer networks with Network Coding Protection

© 2014 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.A major concern among network providers is to endow their networks with the ability to withstand and recover from failures. In recent years, there is a trend in network research referred to as Network Coding Protection (NCP). NCP combines the use of network coding techniques with a proactive protection scheme with the aim of improving network reliability. Although today's network backbone is a multi-layer network formed by the convergence of IP/MPLS and Optical technologies, the information available in the literature related to the performance of NCP schemes in multi-layer network scenarios is yet scarce. In this paper, we propose a novel NCP scheme referred to as DPNC+. The novelty of DPNC+ is that it exploits cross-layer information in order to improve the reliability of multi-layer (IP/MPLS over Optical) networks against link failures. Our evaluation results show that reduction up to 50% -related to protection cost- can be obtained when using the proposed scheme compared to conventional proactive protection techniques.This work was supported by the Spanish Ministry of Economy under contract TEC2012-34682, and the Catalan Research Council (CIRIT) under contract 2009 SGR1508.Peer ReviewedPostprint (author's final draft

An hybrid prediction-based routing approach for reducing routing inaccuracy in optical transport networks

© 2014 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.The advent of network technologies such as Automatically Switched Optical Networks (ASON) and Generalized Multiprotocol Label Switching (GMPLS) pave the way to the deployment of flexible optical transport networks (OTNs). The flexibility of OTNs is a feature highly demanded in dynamic scenarios where lightpaths are continuously set up and torn down on a short-term basis. Unfortunately, the availability and accuracy of network state information in dynamic scenarios are both limited, causing a severe impact on both performance and scalability of Routing and Wavelength Assignment (RWA) algorithms. In this paper we devise a promising routing scheme so-called Hybrid Prediction-based Routing (HPBR). HPBR combines prediction strategies with a novel method to select the most suitable routing metric, aiming at reducing both the dissemination of network state information and the blocking probability. Our findings validate that the proposed scheme significantly reduces the blocking probability compared with other routing schemes, while avoiding the need to periodically disseminate network state information.This work was supported by the Spanish Ministry of Economy under contract TEC2012-34682, and the Catalan Research Council (CIRIT) under contract 2009 SGR1508.Peer ReviewedPostprint (author's final draft

Examen parcial, Marzo 2021: INTRODUCCIÓN AL COMPUTADOR

Resolve

Examen parcial, Marzo 2021: INTRODUCCIÓN AL COMPUTADOR

Resolve

Proactive vs reactive failure recovery assessment in combined fog-to-cloud (F2C) systems

© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.The increasing number of end user devices at the edge of the network, along with their ever increasing computing capacity, as well as the advances in Data Center technologies, paved the way for the generation of Internet of Things (IoT). Several IoT services have been deployed leveraging Cloud Computing and, more recently, Fog Computing. In order to enable efficient control of cloud and fog premises, Fog-to-Cloud (F2C) has been recently proposed as a distributed architecture for coordinated management of both fog and cloud resources. Certainly, many challenges remain unsolved in combined Fog-to-Cloud systems, mostly driven by the dynamicity and volatility imposed by edge devices, such as the recovery of failures at the edge of the network. Indeed, possible failures in computing commodities may be prohibitive for the achievement of the envisioned performance in F2C systems. In this work, we assess proactive and reactive strategies for failure recovery of network elements by modelling them as a Multidimensional Knapsack Problem (MKP) and study the impact of each one on several aspects such as service allocation time, recovery delay and computing resources load. The obtained results show the effect each strategy brings, thus concluding with some analysis on the recovery strategy best suiting distinct IoT scenarios.Peer ReviewedPostprint (published version

The full size validation of remanent life assessment methods

SIGLEAvailable from British Library Document Supply Centre- DSC:7761.039(RD/M--1693/RR88) / BLDSC - British Library Document Supply CentreGBUnited Kingdo