Graphic summary
  • Show / hide key
  • Information


Scientific and technological production
  •  

1 to 50 of 191 results
  • 17th European Conference on Networks and Optical Communications; 7th Conference on Optical Cabling and Infrastruct.

     Martinez Manzanilla, Anny Gabriela; Ramirez Almonte, Wilson; Yannuzzi, Marcelo; Serral Gracia, Rene; Marín Tordera, Eva; Sanchez Lopez, Sergio; Masip Bruin, Javier
    Participation in a competitive project

     Share

  • Access to the full text
    Prediction-based routing as RWA in multilayer traffic engineering  Open access

     Puype, Bart; Marín Tordera, Eva; Colle, Didier; Sanchez Lopez, Sergio; Pickavet, Mario; Masip Bruin, Javier; Demeester, Piet
    Photonic network communications
    Date of publication: 2012-04
    Journal article

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    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has been proposedas a RWA mechanism for optical transport networks; it bases routing not on possibly inaccurate or outdated network state, but instead on previous connections set-up.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.

  • Access to the full text
    Cross-talk effects on the Regenerator Allocation optimization  Open access

     Marín Tordera, Eva; Masip Bruin, Javier; Yannuzzi, Marcelo; Serral Gracia, Rene; Sanchez Lopez, Sergio
    International Congress on Ultra Modern Telecommunications and Control Systems and Workshops
    Presentation's date: 2010-10-19
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    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.

  • Quality of experience aware multimedia provisioning with cross-layer network management

     Serral Gracia, Rene; Marín Tordera, Eva; Yannuzzi, Marcelo; Masip Bruin, Javier; Sanchez Lopez, Sergio
    IEEE Global Communications Conference
    Presentation's date: 2010-12-07
    Presentation of work at congresses

    View View Open in new window  Share Reference managers Reference managers Open in new window

  • Access to the full text
    Simple network management provisioning based on quality of experience feedback  Open access

     Serral Gracia, Rene; Marín Tordera, Eva; Yannuzzi, Marcelo; Masip Bruin, Javier; Sanchez Lopez, Sergio
    Workshop in G/MPLS Networks
    Presentation's date: 2010-07-06
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    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.

    Postprint (author’s final draft)

  • Effcient network performance assessment using Inter-Packet Arrival Times

     Serral Gracia, Rene; Marín Tordera, Eva; Yannuzzi, Marcelo; Masip Bruin, Javier; Sanchez Lopez, Sergio
    IEEE Global Communications Conference
    Presentation's date: 2010-12-06
    Presentation of work at congresses

    View View Open in new window  Share Reference managers Reference managers Open in new window

  • Access to the full text
    Regenerator allocation in WDM networks with uncertainities in the Q factor  Open access

     Marín Tordera, Eva; Yannuzzi, Marcelo; Masip Bruin, Javier; Serral Gracia, Rene; Sanchez Lopez, Sergio
    Workshop on Multilayer Networks
    Presentation's date: 2010-06-15
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    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.

  • Access to the full text
    Cross-layer multimedia quality enforcement through user aware information in wireless networks  Open access

     Serral Gracia, Rene; Yannuzzi, Marcelo; Marín Tordera, Eva; Masip Bruin, Javier; Sanchez Lopez, Sergio
    Workshop on Multilayer Netwoks
    Presentation's date: 2010-06-14
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    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)

  • Access to the full text
    A New Parametric Regenerator Allocation Scheme taking into account Inaccurate Physical Information  Open access

     Marín Tordera, Eva; Yannuzzi, Marcelo; Serral Gracia, Rene; Masip Bruin, Javier; Sanchez Lopez, Sergio
    15th European Conference on Networks and Optical Communications 5th Conference on Optical Cabling and Infrastructure
    Presentation's date: 2010-06-08
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    Regenerator allocation consists on selecting which of the already installed regenerators in a translucent network may be used according to the dynamic traffic requests in order to maximize the quality of the optical signal while minimizing the opaqueness of the network. A recent study has shown that the performance of the regenerator allocation techniques strongly depends on the accuracy of the physical-layer information. The reason of this physical inaccuracy is the drift suffered by the physical-layer parameters during the operation of the optical network. In these conditions, the performance of the Impairment Aware-Routing and Wavelength Assignment (IA-RWA) process might drop sharply when allocating regenerators inappropriately. In this paper, we propose new regenerator allocation schemes taking into account the inherent and unavoidable inaccuracy in the physical-layer information

  • Access to the full text
    Reducing the effects of routing inaccuracy by means of prediction and an innovative link-state cost  Open access

     Masip Bruin, Javier; Marín Tordera, Eva; Yannuzzi, Marcelo; Serral Gracia, Rene; Sanchez Lopez, Sergio
    IEEE communications letters
    Date of publication: 2010-05
    Journal article

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    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.

  • TEC2010-09498-E (WWIC 2011)

     Yannuzzi, Marcelo; Martinez Manzanilla, Anny Gabriela; Serral Gracia, Rene; Marín Tordera, Eva; Sanchez Lopez, Sergio; Ramirez Almonte, Wilson; Masip Bruin, Javier
    Participation in a competitive project

     Share

  • Mozart i Fourier a la platja: música i matemàtiques

     Prat Farran, Joana d'Arc; Guardia Rubies, Jordi; Hernandez Gomez, Maria de Los Angeles; Sanchez Lopez, Sergio; Bernado Ortega, Miguel
    Date: 2010-04-27
    Report

    View View Open in new window  Share Reference managers Reference managers Open in new window

  • DISEÑO MULTINIVEL DE NUEVAS ARQ.Y PROTOCOLOS PARA REDES MULTIDOMINIO

     Ramirez Almonte, Wilson; German Duarte, Martin; Yannuzzi, Marcelo; Sanchez Lopez, Sergio; Serral Gracia, Rene; Marín Tordera, Eva; Martinez Manzanilla, Anny Gabriela; Masip Bruin, Javier
    Participation in a competitive project

     Share

  • Access to the full text
    The Effects of Optimized Regenerator Allocation in Trans-lucent Networks under Inaccurate Physical information  Open access

     Marín Tordera, Eva; Yannuzzi, Marcelo; Masip Bruin, Javier; Sanchez Lopez, Sergio; Martínez, Ricardo; Muñoz González, Raul; Casellas, Ramón; Maier, Guido
    International Conference on Optical Networking Design and Modeling
    Presentation's date: 2010-02-02
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    Optimized regenerator allocation techniques select which of the already installed regenerators in a translucent network must be used in order to maximize the quality of the optical signal while minimizing the opaqueness of the network. Unfortunately, the performance of an optimized regenerator allocation strategy strongly depends on the accuracy of the physical-layer information. In this paper, we investigate the effects of optimized regenerator allocation techniques when the physical-layer information is inaccurate. According to the performed experiments, we conclude that mostly of the current techniques of regenerator usage optimization are only possible when perfect knowledge of physical information is available. Hence, new regenerator allocation schemes taking into account the inherent inaccuracy in the physical-layer information need to be designed.

  • Access to the full text
    OBGP+: An improved path-vector protocol for multi-domain optical networks  Open access

     Yannuzzi, Marcelo; Masip Bruin, Javier; Sanchez Lopez, Sergio; Marín Tordera, Eva
    Optical switching and networking
    Date of publication: 2009-04
    Journal article

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    One of the essential components for the dynamic provisioning of lightpaths across multiple domains is the Routing and Wavelength Assignment (RWA) strategy adopted. The consolidation that path-vector protocols have had in practice, has motivated the optical extension to BGP (OBGP). We claim, however, that a routing model mostly centered on the exchange of reachability information–like the one we have today with BGP or the one offered by OBGP–will not be sufficient for multi-domain optical networks. Routing domains must be able to exchange both reachability as well as aggregated Path-State Information (PSI). Understanding that this is a missing piece in the routing models provided by BGP and OBGP is easy nowadays, but contributing with solutions capable of highly improving the performance of a path-vector without impacting on key aspects of the protocol–fundamentally, its scalability, its convergence properties, and the number of routing messages exchanged between domains–is a challenging task. In this paper we propose OBGP +, which is a very simple extension of a path-vector protocol supporting the computation and advertisement of PSI between optical domains. The PSI that we propose to use is highly condensed in the form of a single integer value. In order to avoid the typical increase in the number of routing messages associated with the update of PSI, we propose to piggy-back the updates in non-dummy Keepalive messages exchanged between OBGP+ neighbors. Extensive simulations reveal that, despite its simplicity: (i) OBGP+ is able to drastically reduce the blocking experienced with a path-vector protocol like OBGP; (ii) OBGP+ needs much less number of routing messages than OBGP to achieve such performance; and (iii) the convergence and restoration features of OBGP+ are also better than those of OBGP, which is particularly important for connections that lack a protection path.

  • Access to the full text
    Regenerator allocation in translucent networks under inaccurate physical information  Open access

     Marín Tordera, Eva; Yannuzzi, Marcelo; Masip Bruin, Javier; Sanchez Lopez, Sergio; Martínez, Ricardo; Muñoz González, Raul; Casellas, Ramón
    Workshop on Multi-layer Networks
    Presentation's date: 2009-12-15
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    Optimized regenerator allocation techniques select which of the already installed regenerators in a translucent network must be used in order to maximize the quality of the optical signal while minimizing the opaqueness of the network. Unfortunately, the performance of an optimized regenerator allocation strategy strongly depends on the accuracy of the physical-layer information. In this paper, we investigate the effects of optimized regenerator allocation techniques when the physical-layer information is inaccurate. According to the performed experiments, we conclude that mostly of the current techniques of regenerator usage optimization are only possible when perfect knowledge of physical information is available

  • Access to the full text
    Quality of experience based provisioning for service providers  Open access

     Serral Gracia, Rene; Marín Tordera, Eva; Yannuzzi, Marcelo; Masip Bruin, Javier; Sanchez Lopez, Sergio
    Workshop on Multilayer Networks
    Presentation's date: 2009-12-15
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    Nowadays Network Operators (NOs) are providing service guaranties to customers by largely overprovisioning their networks, but as the Internet keeps growing, this approach is unveiling important issues in terms of cost and management of the network. To optimize the resource usage, and to reduce the existing overprovisioning, in this paper we present a Cross-layer Autonomic Network Management System that permits Service Providers to perform cost-effective network resource reservation with their NOs. In our novel approach, we use the end-user satisfaction level as the metric used to perform the resource provisioning. We show that our system is capable of achieving a high reduction in operational costs for the Service Providers, while keeping proper bounds in the end-user satisfaction for the offered services.

    Postprint (author’s final draft)

  • Introduction to IP over WDM

     Careglio, Davide; Aracil, Javier; Fernández Palacios, Juan; Jajszczyk, Andrzej; Larrabeiti, David; López, Victor; Masip Bruin, Javier; Sanchez Lopez, Sergio; Spadaro, Salvatore
    Date of publication: 2009-06-01
    Book chapter

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    The simple idea of having IP traffic directly transported over optical Wavelength Division Multiplexing (WDM) technology (“Internet Protocol (IP) over WDM”) has been envisioned as the future for the telecommunication infrastructure. The key point in this infrastructure becomes the switching layer between ubiquitous IP-centric networks and WDM physical layer. An intense debate has been ongoing about which model to adopt, aiming at identifying the degree of optical transparency and the proper flexibility of optical interconnection. Expected migration of switching functions from electronic to optics will be gradual, and will take place in several phases. The first phase is presented in this chapter. It is characterised by the use of the wavelength as a switching granularity; the terms optical circuit switching (Optical Circuit Switching (OCS)), wavelength switching and wavelength routed network are commonly and indifferently used.

  • XARXA MULTINIVELL : IP SOBRE XARXA DE TRANSPORTS (TEC2008-02552-E/TEC)

     Sanchez Lopez, Sergio; Castro Casales, Alberto; Serral Gracia, Rene; German Duarte, Martin; Yannuzzi, Marcelo; Marín Tordera, Eva; Masip Bruin, Javier
    Participation in a competitive project

     Share

  • Mozart i Fourier a la platja: Les matemàtiques al pentagrama

     Prat Farran, Joana d'Arc; Guardia Rubies, Jordi; Sanchez Lopez, Sergio; Hernandez Gomez, Maria de Los Angeles; Bernado Ortega, Miguel; Castell Balaguer, Joan Vicent
    Date: 2009-11-26
    Report

    View View Open in new window  Share Reference managers Reference managers Open in new window

  • Access to the full text
    Performance of translucent optical networks under dynamic traffic and uncertain physical-layer information  Open access

     Yannuzzi, Marcelo; Quagliotti, Marco; Maier, G.; Marín Tordera, Eva; Masip Bruin, Javier; Sanchez Lopez, Sergio; Erangoli, Walter; Tamiri, G
    International Conference on Optical Networking Design and Modeling
    Presentation's date: 2009-02
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    This paper investigates the performance of translucent Optical Transport Networks (OTNs) under different traffic and knowledge conditions, varying from perfect knowledge to drifts and uncertainties in the physical-layer parameters. Our focus is on the regular operation of a translucent OTN, i.e., after the dimensioning and regenerator placement phase. Our contributions can be summarized as follows. Based on the computation of the Personick’s Q factor, we introduce a new methodology for the assessment of the optical signal quality along a path, and show its application on a realistic example. We analyze the performance of both deterministic and predictive RWA techniques integrating this signal quality factor Q in the lightpath computation process. Our results confirm the effectiveness of predictive techniques to deal with the typical drifts and uncertainties in the physical-layer parameters, in contrast to the superior efficacy of deterministic approaches in case of perfect knowledge. Conversely to most previous works, where all wavelengths are assumed to have the same characteristics, we examine the case when the network is not perfectly compensated, so the Maximum Transmission Distance (MTD) of the different wavelength channels may vary. We show that blocking might increase dramatically when the MTD of the different wavelength channels is overlooked.

  • Access to the full text
    Toward a new route control model for multidomain optical networks  Open access

     Yannuzzi, Marcelo; Masip Bruin, Javier; Fabrego, G; Sanchez Lopez, Sergio; Sprintson, A; Orda, A
    IEEE communications magazine
    Date of publication: 2008-06
    Journal article

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    The design of the control plane model for multidomain optical networks poses complex challenges and introduces many open problems. Some initiatives have proposed Optical BGP (OBGP), which is an extension of BGP supporting the advertisement and signaling of optical information between routing domains. We argue, however, that future optical networks offer the opportunity to avoid inheriting the limitations of BGP, especially in terms of routing and traffic engineering control. In this article we present a route control model replacing BGP/OBGP. Extensive simulations confirm that our route control model is able to drastically reduce the blocking experienced with OBGP, and this can be accomplished without increasing the number or frequency of routing updates exchanged between domains.

  • Access to the full text
    OBGP+: A Simple Approach to Drastically Improve OBGP  Open access

     Yannuzzi, Marcelo; Masip Bruin, Javier; Fabregó, Guillem; Sanchez Lopez, Sergio; Sole Pareta, Josep
    International Conference on Optical Networking Design and Modeling
    Presentation's date: 2008-03-12
    Presentation of work at congresses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    During the last few years, the research community has shown an increasing interest in the subject of inter-domain routing in optical networks, so new approaches like the optical extension of BGP, namely OBGP, have arisen. However, it is widely accepted now that a multi-domain routing model mostly centered on the exchange of reachability information – like the one we have today or the one provided by OBGP – is not going to be enough in the future. Routing domains must be able to exchange both, reachability, as well as aggregated Path State Information (PSI). Understanding that there is a missing piece in the routing models provided by BGP and OBGP is easy nowadays, but contributing with solutions capable of highly improving the performance of these routing protocols without increasing the number and frequency of the routing messages exchanged between domains is a challenging task. This study makes the following contributions. First, we propose a straightforward strategy to compute highly aggregated PSI between routing domains. Second, we propose OBGP+, an extended version of OBGP that exploits this PSI to compute inter-domain lightpaths in a highly efficient way. Third, in order to avoid the typical increase in the number of routing messages associated with the update of PSI, we propose to piggy-back these updates in non-dummy Keepalive messages exchanged between OBGP+ neighbors. Extensive simulations made with OPNET in the PAN European network topology reveal that: i) OBGP+ is able to drastically reduce the blocking experienced with OBGP; ii) while even needing less number of routing messages than OBGP to achieve this performance.

  • Cross-Layer Control of Semi-Transparent Optical Networks under Physical-Parameter Uncertainty

     Guido, Maier; Marín Tordera, Eva; Quagliotti, Marco; Erangoli, Walter; Giovanni, Tamiri; Yannuzzi, Marcelo; Masip Bruin, Javier; Sanchez Lopez, Sergio; Sole Pareta, Josep
    Date: 2008-09
    Report

     Share Reference managers Reference managers Open in new window

  • Fast setup of end-to-end paths for bandwidth constrained applications in an IP/MPLS-ATM integrated environment

     Sanchez Lopez, Sergio; Masip Bruin, Javier; Sole Pareta, Josep; Domingo Pascual, Jordi
    Computer networks
    Date of publication: 2007-02
    Journal article

     Share Reference managers Reference managers Open in new window

  • A prediction-based routing mechanism for optical and IP/MPLS networks  Open access

     Marín Tordera, Eva
    Defense's date: 2007-06-14
    Department of Computer Architecture, Universitat Politècnica de Catalunya
    Theses

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    En los últimos años, las nuevas aplicaciones de Internet tales como aplicaciones multimedia, video a demanda, etc, requieren progresivamente mayor capacidad y garantías de calidad de servicio. En ese sentido el modelo de transmisión de tráfico ha ido cambiando hacia Redes Ópticas las cuales proporcionan mayor capacidad y fiabilidad. Esta Tesis se encamina a proporcionar nuevos mecanismos de routing basados en conceptos predictivos para ser aplicados tanto en Redes Ópticas como redes IP/MPLS. El proceso de routing implica seleccionar la ruta (o ruta y longitud de onda en Redes Ópticas) que mejor transporta la información desde el nodo fuente hasta el nodo destino en una red. El routing en redes IP/MPLS se conoce como QoS (Quality of Service) routing cuando calcula rutas que requieren ciertas garantías de calidad de servicio. Por otro lado, el routing en redes ópticas debe seleccionar no sólo el camino físico o ruta sino también la longitud de onda por donde el tráfico debe de ser transportado (conocido como problema de Routing and Wavelength Assignment, RWA). Con el propósito de introducir el escenario del problema ilustraremos el caso para redes ópticas. Las más recientes soluciones propuestas en la literatura para el problema de Routing and Wavelength Assignment, RWA, utilizan mecanismos distribuidos basados en routing de fuente. En routing distribuido, los nodos fuentes seleccionan la ruta y la longitud de onda basándose en la información de estado de la red contenida en sus bases de datos. En este escenario aparece el problema del routing inexacto (routing inaccuracy problem) porque por diferentes razones esta información de estado de la red contenida en las bases de datos no es exacta. El problema del routing inexacto describe el impacto en el rendimiento global debido a tomar decisiones RWA a partir de información inexacta o desactualizada. En general, una parte importante de un mecanismo de routing es la política de actualización. En routing distribuido los nodos fuentes deben intercambiar información sobre los recursos (ancho de banda disponible o longitudes de onda disponibles) de sus enlaces. En la literatura hay diferentes propuestas tratando el problema del routing inexacto. Estos trabajos proponen tanto nuevos algoritmos de routing como nuevas políticas de actualización. Acerca de las políticas de actualización, cuando la frecuencia de actualización de las bases de datos es alta, la información de estado de la red será más precisa. Pero debe existir un compromiso entre la frecuencia de actualización y la sobrecarga de señalización generada por los mensajes de actualización en la red. Incluso, asumiendo en una red óptica que la sobrecarga de señalización no es un problema porque una fibra o longitud de onda se dedica a tareas de señalización (fuera de banda), es posible que la información no sea completamente precisa. Existe un tiempo mínimo de propagación necesario para diseminar esta información en la red y para que se estabilice esta información en las bases de datos. Por otro lado, hasta ahora Internet sólo proporcionaba un modelo de transmisión ‘best effort’. Las aplicaciones a tiempo real mencionadas no pueden ser soportadas en este modelo ‘best effort’, ya que requieren cierto grado de calidad de servicio. El volumen de información que los nodos fuente deben intercambiar cuando se tienen en cuenta los parámetros de calidad de servicio es mayor, y esto impacta negativamente en la sobrecarga de señalización. Esta Tesis propone un nuevo mecanismo de routing, llamado Prediciton-Based Routing (PBR), basado en conceptos predictivos, el cual no necesita mensajes de actualización con información de estado de la red. La principal idea subyacente es que a frecuencias de actualización asequibles la información de estado obtenida en los mensajes de actualización puede no ser útil. Por lo tanto, no utilizar esta información es mejor ya que su efecto tiene un impacto negativo en el rendimiento global de la red. El mecanismo Prediction-Based Routing (PBR) propuesto en esta Tesis tiene el propósito de reducir tanto la sobrecarga de señalización como los efectos negativos del problema del routing inexacto. La información de estado utilizada por los nodos fuentes no se actualiza mediante mensajes sino que es deducida del comportamiento de peticiones de conexión previas. Es decir, el mecanismo PBR tiene en cuenta los bloqueos de conexión previamente producidos en el mismo ‘lightpath’ (ruta y longitud de onda). Además, otra importante característica del PBR es su simplicidad comparado con algoritmos propuestos previamente.

  • MINCOD-MTD: A RWA Algorithm in Semi-Transparent Optical Networks

     Marín Tordera, Eva; Sanchez Lopez, Sergio; Masip Bruin, Javier; Sole Pareta, Josep; Maier, Guido; Santoni, Stefano; Erangoli, Walter; Quagilotti, Marco
    33rd European Conference and Exhibition on Optical Communication
    Presentation's date: 2007-09-16
    Presentation of work at congresses

    View View Open in new window  Share Reference managers Reference managers Open in new window

  • Propuesta del nuevo plan de estudios de segundo ciclo de automática de la EUPVG

     Sanchez Lopez, Sergio
    Jornades de Docència del Departament d'Arquitectura de Computadors. 10 Anys de Jornades
    Presentation of work at congresses

     Share Reference managers Reference managers Open in new window

  • Applying Prediction Concepts to routing on semi-transparent optical transport networks

     Marín Tordera, Eva; Sanchez Lopez, Sergio; Masip Bruin, Javier; Sole Pareta, Josep; Erangoli, W; Santoni, S; Maier, G; Quagliotti, M
    9th International Conference on Transparent Optical Networks 2007
    Presentation's date: 2007-07-01
    Presentation of work at congresses

     Share Reference managers Reference managers Open in new window

  • Towards an Efficient Computation of High Quality primary and backup paths in Multi-domain IP/MPLS Networks

     Yannuzzi, Marcelo; Masip Bruin, Javier; Sanchez Lopez, Sergio; Serral Gracia, Rene; Sole Pareta, Josep; Domingo Pascual, Jordi; Sprintson, A; Orda, A
    Date of publication: 2007-04
    Book chapter

     Share Reference managers Reference managers Open in new window

  • Applying Prediction Concepts to routing on semi-transparent optical transport networks

     Marín Tordera, Eva; Sanchez Lopez, Sergio; Masip Bruin, Javier; Sole Pareta, Josep; Erangoli, W; Santoni, S; Maier, G; Quagliotti, M
    Date of publication: 2007-07
    Book chapter

     Share Reference managers Reference managers Open in new window

  • A RWA Algorithm in Semi-Transparent Optical Networks

     Marín Tordera, Eva; Sanchez Lopez, Sergio; Sole Pareta, Josep; Masip Bruin, Javier; Maier, G; Erangoli, W; Santoni, M; Quagliott, M
    Date of publication: 2007-09
    Book chapter

     Share Reference managers Reference managers Open in new window

  • Optical Network Design and Modeling

     Masip Bruin, Javier; Sanchez Lopez, Sergio
    Date of publication: 2007-12
    Book

     Share Reference managers Reference managers Open in new window

  • Applying Prediction Concepts to Routing on Semi-Transparent Optical Transport Networks

     Sanchez Lopez, Sergio
    9th International Conference on Transparent Optical Networks 2007
    Presentation's date: 2007-07-01
    Presentation of work at congresses

     Share Reference managers Reference managers Open in new window

  • Towards an Efficient Computation of High Quality primary and backup paths in Multi-domain IP/MPLS Networks

     Yannuzzi, Marcelo; Sprintson, A; Masip Bruin, Javier; Orda, A; Sanchez Lopez, Sergio; Serral Gracia, Rene; Sole Pareta, Josep; Domingo Pascual, Jordi
    VI Workshop in G/MPLS Networks
    Presentation's date: 2007-04-12
    Presentation of work at congresses

     Share Reference managers Reference managers Open in new window

  • TEC2007-30330-E (OPTIFLOW)

     Sanchez Lopez, Sergio
    Participation in a competitive project

     Share

  • Lecture notes in computer science

     Sanchez Lopez, Sergio
    Collaboration in journals

     Share

  • Routing Bandwidth Constrained Applications under Inaccurate Network State Information

     Masip Bruin, Javier; Sanchez Lopez, Sergio; Domingo Pascual, Jordi; Sole Pareta, Josep
    Date: 2007-07
    Report

     Share Reference managers Reference managers Open in new window

  • Towards an Efficient Computation of High Quality primary and backup paths in Multi-Domain IP/MPLS Networks

     Sanchez Lopez, Sergio
    VI Workshop in G/MPLS Networks
    Presentation's date: 2007-04-12
    Presentation of work at congresses

     Share Reference managers Reference managers Open in new window

  • MINCOD-MTD: A RWA Algorithm in Semi-Transparent Optical Networks

     Sanchez Lopez, Sergio
    33rd European Conference and Exhibition on Optical Communication
    Presentation's date: 2007-09-16
    Presentation of work at congresses

     Share Reference managers Reference managers Open in new window

  • Propuesta del nuevo plan de estudios de segundo ciclo de automática de la EUPVG

     Sanchez Lopez, Sergio
    Jornades de Docència del Departament d'Arquitectura de Computadors. 10 Anys de Jornades
    Presentation's date: 2007-02-15
    Presentation of work at congresses

     Share Reference managers Reference managers Open in new window

  • The prediction-based routing in optical transport networks

     Marín Tordera, Eva; Masip Bruin, Javier; Sanchez Lopez, Sergio; Sole Pareta, Josep; Domingo Pascual, Jordi
    Computer communications
    Date of publication: 2006-04
    Journal article

     Share Reference managers Reference managers Open in new window

  • Access to the full text
    On the challenges of establishing disjoint QoS IP/MPLS paths across multiple domains  Open access

     Yannuzzi, Marcelo; Masip Bruin, Javier; Sanchez Lopez, Sergio; Domingo Pascual, Jordi; Orda, A; Sprintson, A
    IEEE communications magazine
    Date of publication: 2006-12
    Journal article

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    MPLS is being actively adopted as the core switching infrastructure at the intradomain level. This trend is mainly attributable to the undeniable potential of MPLS in terms of virtual private networks (VPNs) management, traffic engineering (TE), QoS delivery, path protection, and fast recovery from network failures. However, little progress has been made to attain the expected extension of MPLS label-switched paths (LSPs) across domain boundaries. Among the problems that remain unsolved is how to efficiently find and establish primary and protection interdomain LSPs for mission-critical services subject to QoS constraints. This article explores the major limitations hindering the deployment of these kinds of LSPs across multiple domains, in the context of the current interdomain network model. We describe the critical problems faced by the research community, and present our vision on how to rationally overcome some of the problems exposed. Our perspective is that we should be prepared for rather coarse-grained solutions as long as we need to coexist with the current interdomain network model

  • Interdomain RWA Based on stochastic estimation methods and adaptive filtering for optical networks

     Yannuzzi, Marcelo; Masip Bruin, Javier; Sanchez Lopez, Sergio; Marín Tordera, Eva; Sole Pareta, Josep; Domingo Pascual, Jordi
    IEEE Global Communications Conference
    Presentation's date: 2006-11-27
    Presentation of work at congresses

     Share Reference managers Reference managers Open in new window

  • Evaluation of a Combined Intra- and Inter-domain Constraint-based Routing Model for Optical Nretworks

     Sanchez Lopez, Sergio
    V Workshop in MPLS/GMPLS Networks
    Presentation's date: 2006-03-30
    Presentation of work at congresses

     Share Reference managers Reference managers Open in new window

  • Interdomain RWA Based on stochastic estimation methods and adaptive filtering for optical networks

     Yannuzzi, Marcelo; Masip Bruin, Javier; Sanchez Lopez, Sergio; Marín Tordera, Eva; Sole Pareta, Josep; Domingo Pascual, Jordi
    Date of publication: 2006-11
    Book chapter

     Share Reference managers Reference managers Open in new window

  • On the Advantages of Cooperative and Social Smart Route Control

     Yannuzzi, Marcelo; Masip Bruin, Javier; Sanchez Lopez, Sergio; Domingo Pascual, Jordi; Fonte, A; Curado, M; Monteiro, E
    Date of publication: 2006-10
    Book chapter

     Share Reference managers Reference managers Open in new window

  • The Prediction Approach in QoS Routing

     Marín Tordera, Eva; Masip Bruin, Javier; Sanchez Lopez, Sergio; Domingo Pascual, Jordi; Mazip, X
    Date of publication: 2006-06
    Book chapter

     Share Reference managers Reference managers Open in new window

  • The PBR Approach: Analysis, Performance and Perspective

     Sanchez Lopez, Sergio; Masip Bruin, Javier; Marín Tordera, Eva; Sole Pareta, Josep
    Date of publication: 2006-06
    Book chapter

     Share Reference managers Reference managers Open in new window