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A few years ago, an experimental facility composed of networking gear and simulation tools was sufficient for testing the main features of a prototype before the final product could be launched to the Internet market. This paradigm has certainly changed, but the lack of platforms enabling the realistic assessment of the different facets of a product, including cross-cutting trials across different testbeds, poses strong limitations for researchers and developers. In light of this, we present an open platform that offers a versatile combination of heterogeneous experimental facilities called “TEstbed for Future Internet Services” (TEFIS). TEFIS provides a single access point for conducting cutting-edge experiments on testbeds that supply different capabilities, including testbeds dedicated to network performance, software performance, grid computing, and living labs. We shall show that TEFIS covers the entire life-cycle of a multifaceted experiment, with the advantage that a single testrun can seamlessly execute across different experimental facilities. In order to demonstrate the potential and versatility of the TEFIS platform, we describe the deployment of four distinct experiments and provide a set of results highlighting the benefits of using TEFIS. The experiments described in this article cover: (i) the experimentation with an open API called OPENER (which is an open and programmable environment for managing experimentation with SDN applications); (ii) an application for skiers and tourists at the Megève ski resort in France; (iii) an application that can dynamically adapt the Quality of Experience (QoE) of multimedia services for mobile users; and (iv) an augmented reality workspace for remote education and learning purposes based on videoconferencing., Peer Reviewed, Postprint (published version)

The design of new inter-domain optical routing protocols may start from scratch, or on the contrary exploits all the research already developed in IP networks with the Border Gateway Protocol (BGP). Even though the network premises under which BGP was conceived have drastically changed, the pervasive deployment of BGP makes almost impossible its replacement, hence everything indicates that BGP-based routing will remain present in the coming years. In light of this, the approach often used for distributing reachability information and routing inter-domain connections below the IP layer has been to propose extensions to the BGP protocol, what unfortunately exports all well-known BGP weaknesses to these routing scenarios. In this paper we deeply analyze all these problems in order the reader to get a clear idea of the existing limitations inherent to the BGP, before exploring the routing problem in optical networks. Then, focusing on the optical layer we will demonstrate that current optical extensions of BGP do not meet the particular optical layer constraints. We then propose minor, though effective, changes to a path vector protocol overall offering a promising line of work and a simple solution designed to be deployed on a multi-domain and multi-layer scenario. (C) 2013 Elsevier B.V. All rights reserved., Preprint

Internet security poses complex challenges at different levels, where even the basic requirement of availability of Internet connectivity becomes a conundrum sometimes. Recent Internet service disruption events have made the vulnerability of the Internet apparent, and exposed the current limitations of Internet security measures as well. Usually, the main cause of such incidents, even in the presence of the security measures proposed so far, is the unintended or intended exploitation of the loop holes in the protocols that govern the Internet. In this thesis, we focus on the security of two different protocols that were conceived with little or no security mechanisms but play a key role both in the present and the future of the Internet, namely the Border Gateway Protocol (BGP) and the Locator Identifier Separation Protocol (LISP). The BGP protocol, being the de-facto inter-domain routing protocol in the Internet, plays a crucial role in current communications. Due to lack of any intrinsic security mechanism, it is prone to a number of vulnerabilities that can result in partial paralysis of the Internet. In light of this, numerous security strategies were proposed but none of them were pragmatic enough to be widely accepted and only minor security tweaks have found the pathway to be adopted. Even the recent IETF Secure Inter-Domain Routing (SIDR) Working Group (WG) efforts including, the Resource Public Key Infrastructure (RPKI), Route Origin authorizations (ROAs), and BGP Security (BGPSEC) do not address the policy related security issues, such as Route Leaks (RL). Route leaks occur due to violation of the export routing policies among the Autonomous Systems (ASes). Route leaks not only have the potential to cause large scale Internet service disruptions but can result in traffic hijacking as well. In this part of the thesis, we examine the route leak problem and propose pragmatic security methodologies which a) require no changes to the BGP protocol, b) are neithe, Postprint (published version)

In recent years, the advent of new Future Internet (FI) applications is creating ever-demanding requirements. These requirements are pushing network carriers for high transport capacity, energy efficiency, as well as high-availability services with low latency. A widespread practice to provide FI services is the adoption of a multi-layer network model consisting in the use of IP/MPLS and optical technologies such as Wavelength Division Multiplexing (WDM). Indeed, optical transport technologies are the foundation supporting the current telecommunication network backbones, because of the high transmission bandwidth achieved in fiber optical networks. Traditional optical networks consist of a fixed 50 GHz grid, resulting in a low Optical Spectrum (OS) utilization, specifically with transmission rates above 100 Gbps. Recently, optical networks have been undergoing significant changes with the purpose of providing a flexible grid that can fully exploit the potential of optical networks. This has led to a new network paradigm termed as Elastic Optical Network (EON). In recent years, the advent of new Future Internet (FI) applications is creating ever-demanding requirements. A widespread practice to provide FI services is the adoption of a multi-layer network model consisting in the use of IP/MPLS and optical technologies such as Wavelength Division Multiplexing (WDM). Traditional optical networks consist of a fixed 50 GHz grid, resulting in a low Optical Spectrum (OS) utilization. Recently, optical networks have been undergoing significant changes with the purpose of providing a flexible grid that can fully exploit the potential of optical networks. This has led to a new network paradigm termed as Elastic Optical Network (EON). Recently, a new protection scheme referred to as 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 C, En los últimos años la llegada de nuevas aplicaciones del llamado Internet del Futuro (FI) está creando requerimientos sumamente exigentes. Estos requerimientos están empujando a los proveedores de redes a incrementar sus capacidades de transporte, eficiencia energética, y sus prestaciones de servicios de alta disponibilidad con baja latencia. Es una práctica sumamente extendida para proveer servicios (FI) la adopción de un modelo multi-capa el cual consiste en el uso de tecnologías IP/MPLS así como también ópticas como por ejemplo Wavelength Division Multiplexing (WDM). De hecho, las tecnologías de transporte son el sustento del backbone de las redes de telecomunicaciones actuales debido al gran ancho de banda que proveen las redes de fibra óptica. Las redes ópticas tradicionales consisten en el uso de un espectro fijo de 50 GHz. Esto resulta en una baja utilización del espectro Óptico, específicamente con tasas de transmisiones superiores a 100 Gbps. Recientemente, las redes ópticas están experimentado cambios significativos con el propósito de proveer un espectro flexible que pueda explotar el potencial de las redes ópticas. Esto ha llevado a un nuevo paradigma denominado Redes Ópticas Elásticas (EON). Por otro lado, un nuevo esquema de protección llamado Network Coding Protection (NCP) ha emergido como una solución innovadora para habilitar de manera proactiva protección eficiente y ágil usando técnicas de mejora de throughput como es Network Coding (NC). Es un razonamiento lógico pensar que las ventajas relacionadas con throughput de NCP pueden ser magnificadas mediante el espectro flexible proveído por las redes EONs. El objetivo de esta tesis es triple. El primero es estudiar las ventajas de esquemas NCP en un escenario de planificación. Para este propósito, esta tesis se enfoca en el rendimiento de NCP asumiendo un espectro fijo y un espectro flexible. Sin embargo, contrario a escenarios de planificación, en escenarios dinámicos la precisión relacionada de l, Postprint (published version)

Resolved

The recent advances in optical technologies pave the way to the deployment of high-bandwidth services. As reliability becomes a mandatory requirement for some of these services, network providers must endow their networks with resilience capabilities. In recent years, network coding protection (NCP) has emerged as a tentative solution aiming at enabling network resilience in a proactive and efficient way. The goal of this paper is to conduct a techno-economic study to evaluate the protection cost required by NCP schemes deployed either at the IP/MPLS or at the Optical layer of a multi-layer network, as well as its impact on both the capital and operational expenditures (CAPEX, OPEX) of a network provider. Our evaluation results show that a significant reduction in both CAPEX and OPEX is obtained with NCP. Indeed, at least a 49% and 52% of CAPEX and OPEX reduction is achieved respectively in comparison with conventional proactive protection schemes., Peer Reviewed, Postprint (published version)

Optical technologies are the foundations supporting the current telecommunication network backbones due to the high speed transmissions achieved in fiber optical networks. Traditional optical networks consist of a fixed 50 GHz grid, resulting in a low optical spectrum (OS) utilization, specifically with transmission rates above 100 Gbps. This issue is magnified when network resilience capabilities are required. For instance, proactive protection solutions such as Dedicated Protection (DP) are widely used because of their low recovery time. However, a significant drawback of DP is its high utilization of optical bandwidth. Recently, optical networks are undergoing significant changes with the purpose of providing a flexible grid that can fully exploit the potential of optical networks. This has led to a new network paradigm termed as Elastic Optical Networks (EON). Moreover, a novel strategy referred to as network coding (NC) has been proposed with the aim of improving network throughput. In this paper, we propose a proactive protection scheme so-called E-DPNC that combines both the advantages concerning network throughput offered by EON and NC, and the low recovery time of a DP scheme, in order to enable network resilience against optical link failures while also reducing the optical spectrum utilization. Our evaluation results show that our solution reduces the OS utilization by 41% compared with conventional protection schemes deployed on fixed grid scenarios., Postprint (published version)

Border Gateway Protocol (BGP) is the defacto inter-domain routing protocol in the Internet. It was designed without an inherent security mechanism and hence is prone to a number of vulnerabilities which can cause large scale disruption in the Internet. Route leak is one such inter-domain routing security problem which has the potential to cause wide-scale Internet service failure. Route leaks occur when Autonomous systems violate export policies while exporting routes. As BGP security has been an active research area for over a decade now, several security strategies were proposed, some of which either advocated complete replacement of the BGP or addition of new features in BGP, but they failed to achieve global acceptance. Even the most recent effort in this regard, lead by the Secure Inter-Domain Routing (SIDR) working group (WG) of IETF fails to counter all the BGP anomalies, especially route leaks. In this paper we look at the efforts in countering the policy related BGP problems and provide an analytical insights into why they are ineffective. We contend a new direction for future research in managing the broader security issues in the inter-domain routing. In that light, we propose a naive approach for countering the route leak problem by analyzing the information available at hand, such as the RIB of the router. The main purpose of this paper was to position and highlight the autonomous smart analytical approach for tackling policy related BGP security issues. © 2014 IEEE., Peer Reviewed, Postprint (published version)

Route leaks are one of the anomalies of inter-domain routing that have the capacity to produce large Internet service disruptions. Route leaks are caused because of violation of routing policies among Autonomous Systems. Unfortunately, there are not many studies that formally and thoroughly analyze the route leak problem. There exist few conventional solutions that can be used as a first line of defense, such as route filters. However, these palliatives become unfeasible in terms of scalability, mainly due to the administrative overhead and cost of maintaining the filters updated. As a result, a significant part of the Internet is defenseless against route leak attacks. In this paper, we define, describe, and examine the different types of route leaks that threaten the security and reliability of the routing system. Our main contributions can be summarized as follows. We develop a rather basic theoretical framework, which, under realistic assumptions, enables a domain to autonomously determine if a particular route advertisement received corresponds to a route leak. We reason the possible occurrence of route leaks in different scenarios, with the aim of formulating requirements for their identification, and hence thereof prevention to improve routing reliability, Peer Reviewed, Postprint (published version)

The IP-based addressing scheme currently supporting the whole routing architecture embeds some well-known limitations that may significantly hinder the deployment of new applications and services on the Internet. Indeed, it is widely accepted that the unstoppable growth of Internet users is producing two well-known problems: (1) depletion of addresses, motivated by a design limitation of the currently deployed addressing scheme, and (2) the semantic overload of addresses. The main negative consequences of these problems may be summarized as: (i) exacerbating the geometrical growth of the routing tables, and (ii) affecting other network features, such as traffic engineering and mobility, in terms of resilience and disruption tolerant communications.; The relevant consequences that addressing brings to the overall network operation is pushing the networking community to study and propose new addressing architectures that may limit or even remove the negative effects (affecting network performance) stemmed from the currently deployed addressing architecture. To this end, researchers working on this area must have a perfect understanding of the weaknesses and limitations coming up from the nowadays architecture as well as a comprehensive knowledge of the alternatives proposed so far along with the most appealing research trends. Aligned to this scenario, this paper comes up with the aim of assisting the reader to both: (i) get insights about the most prominent limitations of the currently deployed addressing architecture, and (ii) survey the existing proposals based on ID/Locator Split Architectures (ILSAs) including an analysis of pros and cons, as well as a taxonomy aiming at formulating a design space for evaluating and designing existing and future ILSAs. (C) 2013 Elsevier B.V. All rights reserved., Peer Reviewed, Postprint (published version)

Lo que este proyecto pretende es crear una plataforma que permita la gestión y reciclaje de datos. Es decir, una plataforma que gestione los datos para un cliente y a su vez permita reciclarlos para ser reutilizados por la comunidad, para su uso masivo. Por ejemplo para la realización de estudios. Muchos de estos datos tendrán información confidencial por ello su publicación como datos abiertos se realizara limpia de datos confidenciales y de forma masiva. Como caso de uso de nuestra plataforma, realizaremos una aplicación con la colaboración del Hospital de Bellvitge. Esta aplicación capturara, de informes médicos proporcionados por el hospital, los datos necesarios para calcular el riesgo de sangrado y de reinfarto de un paciente. Este tratamiento de la información es de caràcter privado pero reaprovecharemos estos datos para generar con ellos estadísticas abiertas con las que ver que atributos afectan más o menos en el riesgo de las fórmulas. Las estadísticas como hemos comentado anteriormente se realizan de forma masiva y estarán libres de información confidencial sobre el paciente o sobre el hospital. Aprovecharemos todo esto para conocer una tecnologia para el desarrollo de webs que ofrece un gran abanico de opciones de gestión y desarrollo que cada vez esta siendo más utilizada. Esta herramienta es Drupal.

Este proyecto se centra en la emergente arquitectura de Software Defined Networking (SDN) para diseñar y desarrollar una aplicación SDN (SDNApp) basada en el paradigma de Servicios de Red bajo demanda (NaaS) para proporcionar y gestionar en tiempo real la Calidad de Servicio (QoS) extremo a extremo a través de una red para aplicaciones en tiempo real, adaptando el plano de control de la red para satisfacer los requisitos de una aplicación o servicio gracias a la utilización de la interfaz estandarizada de OpenFlow, que permite separar el plano de control del de datos y soporta funciones básicas para ofrecer calidad de servicio. El núcleo de la solución es un algoritmo llamado Pathfinder que es responsable de la demanda dinámica y el aprovisionamiento bajo demanda de recursos de red según los cambios de requisitos de la aplicación. El enfoque adoptado en el algoritmo principal es utilizar un algoritmo “Less-Greedy”. Esto significa que el algoritmo, a diferencia de la mayoría de algoritmos “Greedy” de QoS, no sólo trata de encontrar un camino óptimo, sino que también tiene en cuenta la implicación de otro tráfico en la red utilizando mecanismos de supervisión del estado de enlaces y puertos. La SDNApp Pathfinder es un módulo externo en desarrollo que ha sido diseñado para ser embebido en la Capa de Control de Red (NCL) desarrollada dentro del proyecto europeo FP7 OFERTIE, que se ha implementado dentro del “framework” OpenNaaS que permite a las aplicaciones suministrarse de servicios bajo demanda, de recursos de red y capacidades dinámicamente. Sin embargo, el proyecto tiene en cuenta también el funcionamiento de la aplicación central junto con un controlador OpenFlow y utiliza sus técnicas específicas para proporcionar y mantener la Calidad de Servicio de extremo a extremo. Sin la NCL, se depende de aplicaciones paralelas como mecanismos para realizar todas sus funcionalidades junto un controlador OpenFlow en una red de un solo dominio. Actualmente, el algoritmo está

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Taula rodona duta a terme dins el marc de l'edició del Face2Face 2013 a l'EPSEVG., Taula rodona duta a terme dins el marc de l'edició del Face2Face 2013 a l'EPSEVG.

©2013 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., As researchers in the networking area keep adopting experimental network testing as a valid mechanism to develop, validate, and improve their research, it becomes more apparent that an overall framework supporting and assisting during the experimentation process is necessary. Particularly, this assistance is relevant in processes such as experiment preparation, or results validation. As a consequence, the goal, and thus the contribution, of this paper is twofold, on the one hand we propose a novel set of guidelines which establish the set of requirements any testbed for network experimentation should follow. On the other hand, as the other relevant contribution of this work, we propose a mechanism for generating meta-data information on the experiments that ease the publication of the obtained datasets. Finally, as a usecase, we present a particular implementation of this framework which we deploy in a real scenario to prove the capabilities of the proposed testing procedure., This work was partially funded by Spanish Ministry of Science and Innovation under contract TEC2009-07041, and the Catalan Government under contract 2009 SGR1508., Peer Reviewed, Postprint (author's final draft)

©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., Recent research in the field of Wireless Sensor Networks (WSNs) has demonstrated the advantages of using learning automata theory to steer the routing decisions made by the sensors in the network. These advantages include aspects such as energy saving, energy balancing, increased lifetime, the selection of relatively short paths, as well as combinations of these and other goals. In this paper, we propose a very simple yet effective technique, which can be easily combined with a learning automaton to dramatically improve the performance of the routing process obtained with the latter. As a proof-of-concept, we focus on a typical learning automata-based routing process, which aims at finding a good trade off between the energy consumed and the number of hops along the paths chosen. In order to assess the performance of this routing process, we apply it on a WSN scenario where a station S gathers data from the sensors. In this typical WSN setting, we show that our combined technique can significantly improve the decisions made with the automata; and more importantly, even though the proof-of-concept particularizes somehow the automata and their behavior, the technique described in this paper is general in scope, and therefore can be applied under different routing methods and settings using learning automata., This work was supported in part by the Spanish Ministry of Science and Innovation under contract TEC2009-07041, and by the Catalan Government under contract 2009 SGR1508., Peer Reviewed, Postprint (author's final draft)

© 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)

Multilayer traffic engineering (MLTE) allows coping with ever-increasing and varying traffic demands in IP-over-Optical multilayer networks. It utilizes cross-layer TE (Traffic Engineering) techniques to provision optical lightpath capacity to the IP/MPLS (Internet Protocol/ Multi-Protocol Label Switching) logical topology on-demand. Such provisioning however causes optical connection arrival rates that pose strong performance requirements to Routing and Wavelength Assignment (RWA) strategies. Collecting up-to-date network information for the RWA with rapidly changing network states can be quite difficult. Exposing optical layer state information to the IP layer in the overlay model, or transforming this optical layer information in a workable representation in an integrated control plane is similarly problematic. Prediction-Based Routing (PBR) has been proposedas a RWA mechanism for optical transport networks; it bases routing not on possibly inaccurate or outdated network state, but instead on previous connections set-up. In this article, we propose to implement PBR as the RWA mechanism in the optical layer of a multilayer network, and use the predictive capabilities of PBR to expose dynamic optical network information into the multilayer traffic engineering algorithm with minimal control plane overhead. Some simulations show the benefits of using the PBR in the optical layer for MLTE purposes., Postprint (published version)

Providing networks with QoS guarantees is one of the key issues to support current and future expected clients' demands. In this scenario, QoS routing is definitely critical as being responsible for defining those optimal routes supporting traffic forwarding throughout the whole network. This paper proposes two new QoS-aware RWA algorithms dealing with the routing inaccuracy problem, aiming at reducing blocking probability while limiting signaling overhead and balancing network load. The proposed algorithms extend the work already published by the authors on prediction based routing by adding a novel fuzzy-based technique featuring a powerful tool for modeling uncertainty. The proposed algorithms are compared with a well-known RWA algorithm and results show the benefit of introducing the fuzzy techniques in the RWA selection., Peer Reviewed, Postprint (published version)

The Path Computation Element (PCE) is positioned nowadays as one of the solutions that almost every carrier will eventually deploy. The PCE architecture as well as a number of components, including the PCE Communication Protocol (PCEP), have been standardized by the IETF. However, a number of challenges remain to be solved on its way from standards to deployment. In particular, the existing proposals for multilayer path computation within the PCE framework need to be further developed and tested, before considering their possible integration into operational networks. This is especially true for the interoperability of the various PCE implementations and the extensions such as the Virtual Network Topology Manager (VNTM) which cannot be taken for granted. This paper presents a functional implementation of coordinated computation of multilayer paths supported through inter-layer PCE communication, where one PCE is developed by industry and the other as an open-source effort. To this end, we consider an IP/MPLS network deployed over a Wavelength Switched Optical Network (WSON), each of which deploying its own PCE, in an attempt to create an inter-operable multilayer solution. We discuss the key challenges that the research community will face in this area, which in turn will drive a considerable part of the upcoming efforts in terms of standardization, Postprint (published version)

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Inclou solució al problema 2, Resolved

PFC del programa Erasmus EPS, Treball desenvolupat dins el marc del programa 'European Project Semester'., This report explains the EPS-project of Energy-Efficiency in wirehood machines and expands on how energy can be saved. Due to the fact that one of the machines is less efficient than the other one the EPS-Team had to detect the reasons of this deviation. The aim of the project was furthermore to figure out how wasting of energy by friction, heat dissipation, acoustic emission and non-regenerating could be avoided by showing up logical measurements and the consequent results. These studies test whether economic or environmental advantages exist. Therefore different ways to reduce dissipation of energy were taken into account. These are the usage of new and better lubrication-oil, different types of components and take decelerating energy to move other devices were taken into account. Thus, the operator can now be encouraged to invest in adapted components or an improved wirehood machine and see in this way if there is a potential return on his investment.

Este PFC ha sido el resultado de un trabajo conjunto con el centro de investigación CRAAX y ha consistido en la optimización MPT-BGP. Para ello, el principal objetivo ha sido la implementación de una topología de red real con routers Quagga para optimizar el rendimiento del tráfico mediante ingeniería de tráfico ínter-dominio. Para que tenga lugar este intercambio de tráfico entre sistemas autónomos (AS) se ha utilizado el protocolo BGP (Border Gateway Protocol) ya que es el que utilizan la mayoría de los Proveedores de Servicios de Internet (ISP). Se ha controlado la información de encaminamiento manipulando los diferentes atributos de BGP. Para llevar a cabo esta implementación, se ha utilizado VirtualBox, una aplicación que permite emular diferentes sistemas operativos al mismo tiempo. Una vez implementado el escenario, se ha utilizado MGen para generar tráfico real controlado y congestionar de esta manera los enlaces para posteriormente implementar un algoritmo de optimización donde el objetivo es la asignación de flujos a enlaces minimizando ciertos criterios como el ancho de banda no utilizado en los enlaces y el costo asociado a transportar tráfico por cada enlace. De aquí se han sacado algunas tablas y gráficas como son el throughput o la latencia y se han analizado estos resultados.

Next Generation Internet points out the challenge of addressing "things" on both a network with (wired) and without (wireless) infrastructure. In this scenario, new efficient and scalable addressing and routing schemes must be sought, since currently proposed solutions can hardly manage current scalability issues on the current global Internet routing table due to for example multihoming practices. One of the most relevant proposals for an addressing scheme is the Locator Identifier Separation Protocol (LISP) that focuses its key advantage on the fact that it does not follow a disruptive approach. Nevertheless, LISP has some drawbacks especially in terms of reachability in the border routers. In face of this, in this paper we propose a protocol so-called LISP Redundancy Protocol (LRP), which provides an interesting approach for managing the reachability and reliability issues common on a LISP architecture, such as those motivated by an inter-domain link failure., Postprint (published version)

This paper studies the impact of considering crosstalk effects in the IA-RWA process and in the regenerator allocation algorithms. First of all, we evaluate if the regenerator allocation optimization is still useful when the crosstalk effects are considered. For this end we improve a simple physical model which computes the quality of the signal factor for each optical connection. Until now this physical model was unaware of the physical layer impairments depending on the interference between different optical connections, such as the crosstalk. Following the same simple methodology we add the switching node crosstalk effect to the computation of the quality of the signal factor. Once the new physical model is enhanced we evaluate the impact of the crosstalk on the performance of IA-RWA algorithms that optimize the use of the regenerators; and also we evaluate the impact of different e wavelength assignation techniques., Postprint (published version)

Despite the efforts made towards the convergence of packet and circuit switched technologies, the isolation between the Internet and the optical Network Management Systems (NMSs) remains unsolved. Today, carriers have nothing but manual means to coordinate the provisioning between the routers and L1 switches, and much less to communicate and coordinate policy rules, or failures between the IP networks and Ethernet/optical networks. In this paper, we outline the strengths of an easy-to-deploy solution, which can overcome the current separation between the IP and the optical NMSs. The solution consists of an adapter(a middle-box), especially designed to provide a simple, reliable, and automated communication channel between the two management layers. The adapter that we conceive will enable automated interoperability between the IP and the optical NMSs, in support of coordinated actions such as: i) IP service provisioning; ii) IP/MPLS offloading; and iii) coordinated self-healing. We contend that our approach not only eliminates the need for large scale integration into a single multi-layer management system, but also bridges the communication gap between two management ecosystems that are currently isolated., Postprint (published version)

The advantages of optical transparency are still confined to the boundaries of a domain, since the optical signals are subject to O/E/O conversions at the border nodes that separate two optical domains. The extension of transparent connections across domains requires advances both in the modeling of the impairments suffered by the optical signals as well as in devising strategies to exploit such models in practice. In this latter regard, one of the main challenges is to design information exchange models and protocols enabling optical bypass without disclosing detailed physical-layer information among domains. In this paper, we focus on the modeling and the exchange of impairmentrelated information between optical domains. We propose a model that conveniently captures the degradation experienced by an optical signal along a lightpath, and describe it use in the frontier between two neighbor domains. Our approach respects the privacy and administrative limits of carrier networks, while enabling the provision of transparent connections beyond domain boundaries. The model and strategies proposed in this paper generalize the contributions made by some of the most relevant works in the field, providing in this way a first attempt toward a unifying view and theory for quantifying the transmission impairments in DWDM optical networks., Peer Reviewed, Postprint (author’s final draft)

In this paper we present a Multimedia Wireless Management System, which can be used on-line to assess and guarantee the quality of multimedia traffic in a wireless network. The proposed platform uses both network and application layer metrics to build up a scalable quality assessment of multimedia traffic. Moreover, the system provides traffic provisioning capabilities by coordinating the network access and usage both from the wireless node and from the network access point. These two combined features permit our platform to guarantee a satisfactory multimedia user experience in wireless environments. We evaluate our proposal by issuing an experimental deployment in a testbed and performing a series of tests under different network situations to demonstrate the Quality of Experience guaranties of our system. The results show that the quality of video perceived by end-users is considerably improved compared to the typical wireless network., Peer Reviewed, Postprint (author’s final draft)

Network performance measurements have been broadly used in order to debug and to assess the reliability of the network. In general performance measurement is a resource consuming process, which in practice derives in hardly scalable systems. However, in order to control and monitor network resource usage and to assess the quality of multimedia traffic, it is broadly accepted that efficient and scalable network performance evaluation infrastructures must be present in nowadays networks. Nevertheless, most of current research is focused on the assessment of the different performance metrics in order to determine if the quality of the delivered service is correct. Differently, the main contribution presented in this paper, relies on the fact that the accurate estimation of the network metrics is generally not necessary, given that it is much more efficient to directly detect service disruptions. To this end, we propose an algorithm to detect anomalies on the service level delivered to the users. Our solution is based on the distance measurement between acquired reference distributions on the Inter-Packet Arrival Times. This simple to measure time-series permit to detect very efficiently QoS disruptions, making of the solution a very good candidate to be used on Service Level Agreement assessment systems, as we prove in our experimental set up, where we evaluate the performance and accuracy of the proposal in a real scenario., Peer Reviewed, Postprint (published version)

This paper presents a Cross-layer Network Management System (NMS) that allows Service Providers (SPs) to perform cost-effective network resource reservations with their Network Operators (NOs). The novelty of our NMS is that it offers a fresh and promising approach to use the endusers satisfaction level as the metric to perform the resource management. We show that our system is capable of achieving considerable reductions in the operational costs of SPs, while keeping proper bounds in the end-user satisfaction for the offered multimedia services., Peer Reviewed, Postprint (published version)

The performance of the regenerator allocation algorithms in WDM networks strongly depends on the accuracy of the physical-layer information such as the Q factor. In a translucent WDM network the already installed regenerators along the lightpath are allocated based on the physical information (Q factor) in order to maximize the quality of the optical signal while minimizing the opaqueness of the network. The Q factor used by the IA-RWA algorithms is usually inaccurate due to the drift suffered by the physical-layer parameters during the operation of the optical network. In this scenario the allocation of regenerators is not optimized and then the performance of the network is worsened. New regenerator allocation schemes should be proposed in order of counteracting the inherent and unpredictable uncertainty in the physical-layer information., Postprint (published version)

The increase in multimedia content on the Internet has created a renewed interest in quality assessment. There is however a main difference from the traditional quality assessment approaches, as now, the focus relies on the user perceived quality, opposed to the network centered approach classically proposed. In this paper we overview the most relevant challenges to perform Quality of Experience (QoE) assessment in IP networks and highlight the particular considerations necessary when compared to alternative mechanisms, already deployed, such as Quality of Service (QoS). To assist on the handling of such challenges we first discuss the different approaches to Quality of Experience assessment along with the most relevant QoE metrics, and then we discuss how they are used to provide objective results about user satisfaction., Peer Reviewed, Postprint (author’s final draft)

The routing inaccuracy problem is one of the major issues impeding the evolution and deployment of Constraint- Based Routing (CBR) techniques. This paper proposes a promising CBR strategy that combines the strengths of prediction with an innovative link-state cost. The latter explicitly integrates a two-bit counter predictor, with a novel metric that stands for the degree of inaccuracy (seen by the source node) of the state information associated with the links along a path. In our routing model, Link-State Advertisements (LSAs) are only distributed upon topological changes in the network, i.e., the state and availability of network resources along a path are predicted from the source rather than updated through conventional LSAs. As a proof-of-concept, we apply our routing strategy in the context of circuit-switched networks. We show that our approach considerably reduces the impact of routing inaccuracy on the blocking probability, while eliminating the typical LSAs caused by the traffic dynamics in CBR protocols., Postprint (published version)

This paper presents a promising Autonomic Network Management System (ANMS) that allows Service Providers (SPs) to perform efficient network resource provisioning with their Network Operators (NOs). The novelty of our ANMS is that it offers an starting point to use the end-users perceived quality as a metric to manage the network resources. We show that our system is capable of achieving considerable reductions in the operational costs of SPs, while keeping proper bounds in the end-user satisfaction for the offered multimedia services., Peer Reviewed, Postprint (author’s final draft)

Quality assessment of multimedia traffic is a hot topic. In this paper we present a Multimedia Management System, which can be used on-line to assess and guarantee the quality of multimedia traffic in a wired and wireless network. The proposed platform uses both network and application layer metrics to build up a scalable quality assessment framework. The core of this framework provides means for traffic provisioning capabilities by coordinating the network access and usage both from the wireless node and from the network access point. These two combined features permit our platform to guarantee a satisfactory multimedia user experience. We evaluate our proposal by issuing an experimental deployment in a testbed and performing a series of tests under different network situations to demonstrate the Quality of Experience guaranties of our system. The results show that the quality of video perceived by endusers is considerably improved compared to the typical wireless network., Postprint (author’s final draft)