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  • Multi-domain optical routing: Is there life beyond extending BGP?

     Marín Tordera, Eva; Masip Bruin, Javier; Yannuzzi, Marcelo; Serral Gracia, Rene
    Optical switching and networking
    Date of publication: 2014-01-01
    Journal article

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    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.

  • Metrics and QoE assessment in P2PTV applications

     Serral Gracia, Rene; Yannuzzi, Marcelo; Marín Tordera, Eva; Martinez Manzanilla, Anny Gabriela; Masip Bruin, Javier
    International journal of internet protocol technology
    Date of publication: 2013
    Journal article

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    Peer-to-peer (P2P) is a growing technology offering an affordable platform to deploy distributed services and streaming of multimedia content through peer-to-peer television (P2PTV). Nevertheless, to promote such technology it is necessary to provide a solid streaming quality assessment mechanism. In this context, legacy solutions tied to service level agreements are no longer suitable, as for P2P systems, the service consumers become an active part by assisting in the service delivery. To overcome this limitation, we present a generic multi-layer monitoring and management framework to assess the quality of service (QoS) and the quality of experience (QoE) of multimedia traffic in any P2PTV streaming application. We also demonstrate the usefulness of our solution, by analysing the performance of a real streaming application in a P2PTV environment.

  • FRA: A new fuzzy-based routing approach for optical transport networks

     Ahvar, Ehsan; Marín Tordera, Eva; Yannuzzi, Marcelo; Masip Bruin, Javier; Ahvar, S.
    European Conference on Networks and Optical Communications
    Presentation's date: 2012
    Presentation of work at congresses

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    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.

  • Multi-Layer quality assessment framework for P2PTV applications

     Serral Gracia, Rene; Martinez Manzanilla, Anny Gabriela; Marín Tordera, Eva; Yannuzzi, Marcelo; Masip Bruin, Javier
    IEEE International Conference on Communications
    Presentation of work at congresses

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    The success of Peer-to-Peer (P2P) overlay networks has led to its broad adoption on different scenarios, thereby increasing the set of features present on such protocols, e. g., audio and video-conferencing, streaming of multimedia content using Peer-to-Peer TeleVision (P2PTV), and so on. The wide acceptance of P2P multimedia streaming by the end-users has captured the attention of content providers, making it a suitable candidate to be adopted as technology for the offered multimedia services. Nevertheless, to deliver a proper service, content providers, need to quantify and assess the quality perceived by the users. In the past, this assessment was embedded into Service Level Agreements under the client/server paradigm, but with the introduction of P2P, these solutions became unsuitable. To overcome this limitation, we present a Monitoring and Management Framework to assess the Quality of Service and the Quality of Experience of multimedia traffic in any P2PTV streaming application.

  • EQR: a new energy-aware query-based routing protocol for wireless sensor networks

     Ahvar, Ehsan; Serral Gracia, Rene; Marín Tordera, Eva; Masip Bruin, Javier; Yannuzzi, Marcelo
    Lecture notes in computer science
    Date of publication: 2012
    Journal article

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    Over the last years, a number of query-based routing protocols have been proposed for Wireless Sensor Networks (WSNs). In this context, routing protocols can be classified into two categories, energy savers and energy balancers. In a nutshell, energy saving protocols aim at decreasing the overall energy consumed by a WSN, whereas energy balancing protocols attempt to efficiently distribute the consumption of energy throughout the network. In general terms, energy saving protocols are not necessarily good at balancing energy and vice versa. In this paper, we introduce an Energy-aware Query-based Routing protocol for WSNs (EQR), which offers a good trade-off between the traditional energy balancing and energy saving objectives. This is achieved by means of learning automata along with zonal broadcasting so as to decrease the total energy consumption. We consider that, in the near future, EQR could be positioned as the routing protocol of choice for a number of query-based WSN applications, especially for deployments where the sensors show moderate mobility.

  • 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
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    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

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    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.

  • Modeling physical-layer impairments in multi-domain optical networks

     Yannuzzi, Marcelo; Marín Tordera, Eva; Serral Gracia, Rene; Masip Bruin, Javier; Gonzalez de Dios, Oscar; Jimenez Chico, Javier; Verchere, Dominique
    International Conference on Optical Networking Design and Modeling
    Presentation's date: 2011-02-08
    Presentation of work at congresses

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    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.

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    An Approach to a Fault Tolerance LISP Architecture  Open access

     Martinez Manzanilla, Anny Gabriela; Ramírez, Wilson; German Duarte, Martin; Serral Gracia, Rene; Marín Tordera, Eva; Yannuzzi, Marcelo; Masip Bruin, Javier
    International Conference on Wired/Wireless Internet Communications
    Presentation's date: 2011-06
    Presentation of work at congresses

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    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.

  • TEstbed for Future Internet Services

     Masip Bruin, Javier; Marín Tordera, Eva; Serral Gracia, Rene; Yannuzzi, Marcelo
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    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

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    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

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    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

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    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.

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  • 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

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    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

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    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.

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    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

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    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.

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    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

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    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

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    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

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    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.

  • PREPARACIÓ PROPOSTA X-AGON AL FP7

     Marín Tordera, Eva; Serral Gracia, Rene; Yannuzzi, Marcelo; Masip Bruin, Javier
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  • PREPARACIÓ PROPOSTA OASIS AL FP7

     Serral Gracia, Rene; Yannuzzi, Marcelo; Marín Tordera, Eva; Masip Bruin, Javier
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  • PREPARACIÓ PROPOSTA HAROON AL FP7

     Serral Gracia, Rene; Yannuzzi, Marcelo; Marín Tordera, Eva; Masip Bruin, Javier
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  • PREPARACIÓ PROPOSTA X-TALK AL FP7

     Marín Tordera, Eva; Serral Gracia, Rene; Yannuzzi, Marcelo; Masip Bruin, Javier
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  • 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
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  • FP7-258300-ONE

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

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  • ONE:PREPARCIÓN PROPUESTA AL FP7

     Serral Gracia, Rene; Masip Bruin, Javier; Marín Tordera, Eva; Yannuzzi, Marcelo
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  • 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
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    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

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    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.

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    A survey on physical layer impairments aware routing and wavelength assignment algorithms in optical networks  Open access

     Azodolmolky, S; Klinkowski, Miroslaw; Marín Tordera, Eva; Careglio, Davide; Sole Pareta, Josep; Tomkos, Ioannis
    Computer networks
    Date of publication: 2009-03
    Journal article

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    Optical networks are moving from opaque and translucnet architectures towards all-optical (transparent) architecutres. In translucent architectures a small amount of regeneration (e.g. optical-electronic-optical conversion) is available in the network. The incorporation of the physical impairments in the routing and wavelenghth assignment (RWA) problem in transparent optical networks has recently received some attention from the research communities. this work compiles a comprehensive survey of the proposed algorithms that address this issue. the physical layer impairments and related classification in optical networks are initially presented followed by physical layer impairments (PLI) constrained and aware RWA algorithms. Algorithmic approach, current PLI-RWA proposals, impact of wavelenght conversation on these algorithms, protection and resilience considerations, and proposed extensions to control planes are covered in this work. Further research topics are presented in this study.

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    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

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    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.

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    On the offline physical layer impairment aware RWA algorithms in transparent optical networks: state-of-the-art and beyond  Open access

     Azodolmolky, Siamak; Pointurier, Yvan; Klinkowski, Miroslaw; Marín Tordera, Eva; Careglio, Davide; Sole Pareta, Josep; Angelou, Marianna; Tomkos, Ioannis
    International Conference on Optical Networking Design and Modeling
    Presentation of work at congresses

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    In transparent optical networks with no regeneration, the problem of capacity allocation to traffic demands is called "Roting and Wavelength Assignment". Much work on this topic recently has focused on the dynamic case, whereby demands arrive and must be served in real-time. In addition, due to lack of regeneration, physical impairments accumulate as light propagates and QoT may become inappropiate (e.g., too high Bit Error Rate). Considering the physical layer impairments in the network planning phase gives rise to a class of RWA algorithms: offline Physical Layer Impairment Aware- (PLIA-)RWA. This paper makes a survey of such algorithms, proposes a taxonomy, and a comparison between these algorithms for common metrics. We also propose a novel offline PLIA-RWA algorithm, called POLIO-RWA, and show through simulations that it decreases blocking rate compared with other PLIA-RWA algorithms.

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    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

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    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

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    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

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    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)

  • Proposta X-TALK Call 5 ICT

     Serral Gracia, Rene; Yannuzzi, Marcelo; Marín Tordera, Eva; Masip Bruin, Javier
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    Improving IA-RWA algorithms in translucent networks by regenerator allocation  Open access

     Marín Tordera, Eva; Martinez, R; Muñoz, R; Casellas, R; Sole Pareta, Josep
    International Conference on Transparent Optical Networks
    Presentation of work at congresses

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    In this paper we present the impact of considering regenerator allocation when selecting routes and wavelengths in translucent networks. In the regular operation of translucent networks, i.e. with dynamic traffic, we assume that a certain number of 3R regenerators are installed in some nodes of the network. These regenerators break the optical transparency of the lightpaths, but allow establishing the optical connections with the required optical signal quality. We show the performance improvement of the MINCOD-Q IA-RWA algorithm when an efficient regenerator allocation policy is employed (optical regeneration is only performed when the signal quality goes bellow a pre-established threshold). Under this policy, the (extended) MINCOD-Q algorithm performs slightly better in terms of blocking probability, but and most important, this figure is obtained with a significant reduction of the number of 3R regenerators installed in the network.

  • 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

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  • PREPARACIÓ PROPOSTA PREFIX AL VII PM (TEC2008-02406-E)

     Marín Tordera, Eva; Masip Bruin, Javier
    Participation in a competitive project

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  • COST ACTION IC0806

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

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  • EL·LABORACIÓ PROPOSTA PROJECTE 7è PROG. MARC

     Marín Tordera, Eva; Masip Bruin, Javier
    Participation in a competitive project

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  • 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

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    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.

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    Improving the Performance of Route Control Middleboxes in a Competitive Environment  Open access

     Yannuzzi, Marcelo; Masip Bruin, Javier; Marín Tordera, Eva; Domingo Pascual, Jordi; Fonte, Alexandre; Monteiro, Edmundo
    IEEE network
    Date of publication: 2008-09
    Journal article

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    Multihomed subscribers are increasingly adopting intelligent route control solutions to optimize the cost and end-to-end performance of the traffic routed among the different links connecting their networks to the Internet. Until recently, IRC practices were not considered adverse, but new studies show that in a competitive environment, they can lead to persistent traffic oscillations, causing significant performance degradation rather than improvements. To cope with this, randomized IRC techniques were proposed. However, the proliferation of IRC products raises concerns, given that randomization becomes less effective as the number of interfering IRC systems increases. In this article, we present a more scalable route control strategy that can better support the foreseeable spread of IRC solutions. We show that by blending randomization with adaptive filtering techniques, it is possible to drastically reduce the interference between competing route controllers, and this can be achieved without penalizing the end-to-end traffic performance. In addition to the potential improvements in terms of scalability and performance, the route control strategy outlined here has various practical advantages. For instance, it does not require any kind of protocol or coordination between the competing IRC middleboxes, and it can be adopted readily today because the only requirement is a software upgrade of the available route controllers.

  • 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

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  • Coverage vs. Cost for PCE-based MPLS Multi-Domain Networks

     Yannuzzi, Marcelo; Masip Bruin, Javier; Serral Gracia, Rene; Marín Tordera, Eva; Sprintson, A; Orda, and A
    Date: 2008-01
    Report

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    Maximum Coverage at Minimum Cost for Multi-Domain IP/MPLS Networks  Open access

     Yannuzzi, Marcelo; Masip Bruin, Javier; Serral Gracia, Rene; Marín Tordera, Eva; Sprintson, Alex; Orda, Ariel
    IEEE INFOCOM 2008, The 27th Conference on Computer Communications
    Presentation's date: 2008-04-14
    Presentation of work at congresses

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    At present, service providers have several incentives to extend the reach of long-lived MPLS paths across domains. Providers, however, will face a number of trade-offs while choosing the optimal set of MPLS paths to be established. In this paper, we focus on the multi-objective decision problem of maximizing the traffic demands to be covered by long-lived MPLS paths from a source domain S to its major destination domains, while minimizing the monetary costs incurred. The problem is formulated subject to a budget constraint, which assures the minimum expected revenue for the provider in S. A major advantage of the analysis and solution proposed in this paper is that it can be easily generalized, and applied in other settings where constrained problems considering maximum coverage vs. cost are critical.

  • 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

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    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

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  • 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

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  • 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

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  • 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

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

     Marín Tordera, Eva
    9th International Conference on Transparent Optical Networks 2007
    Presentation's date: 2007-07-02
    Presentation of work at congresses

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  • 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

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