René Serral-Gracià

René Serral-Gracià
Universitat Politècnica de Catalunya | UPC · Department of Computer Architecture (DAC)

PhD in Computer Science

About

69
Publications
15,849
Reads
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975
Citations
Citations since 2017
3 Research Items
592 Citations
2017201820192020202120222023020406080100120
2017201820192020202120222023020406080100120
2017201820192020202120222023020406080100120
2017201820192020202120222023020406080100120
Additional affiliations
September 2004 - present
Universitat Politècnica de Catalunya
Position
  • Professor (Associate)

Publications

Publications (69)
Article
We propose the TelcoFog architecture as a novel, secure, highly distributed, and ultra-dense fog computing infrastructure, which can be allocated at the extreme edge of a wired/wireless network for a telecom operator to provide multiple unified, cost-effective, and new 5G services, such as NFV, MEC, and services for third parties (e.g., smart citie...
Chapter
ith the continuous growth of current networks, configuration management has become increasingly relevant to the Information and Communication Technologies (ICT) field. Despite numerous standardization efforts, network administrators continue to rely on Command-Line Interfaces (CLIs) to modify and control the configuration of network devices. Nevert...
Conference Paper
Full-text available
Hybrid Software-Defined Networks (SDNs) are growing at a remarkable speed, so network administrators need to deal with the configuration of a plethora of devices including OpenFlow elements, traditional equipment, and nodes supporting both OpenFlow and traditional features. The OpenFlow Management and Configuration Protocol (OF-CONFIG) is positione...
Article
Full-text available
The current device-centric protection model against security threats has serious limitations. On one hand, the proliferation of user terminals such as smartphones, tablets, notebooks, smart TVs, game consoles, and desktop computers makes it extremely difficult to achieve the same level of protection regardless of the device used. On the other hand,...
Article
The Border Gateway Protocol (BGP) is the de facto inter-domain routing protocol in the Internet, thus it plays a crucial role in current communications. Unfortunately, it was conceived without any internal security mechanism, and hence is prone to a number of vulnerabilities and attacks that can result in large scale outages in the Internet. In lig...
Conference Paper
Full-text available
This paper examines some of the most promising and challenging scenarios in IoT, and shows why current compute and storage models confined to data centers will not be able to meet the requirements of many of the applications foreseen for those scenarios. Our analysis is particularly centered on three interrelated requirements: 1) mobility; 2) relia...
Conference Paper
Full-text available
A route leak can be defined as a security gap that occurs due to the infringement of the routing policies that any two Autonomous Systems (ASes) have agreed upon. Route leaks are seemingly simple, but hard to resolve since the ASes keep their routing policies confidential. Indeed, the traditional palliatives, such as the utilization of route filter...
Chapter
This chapter analyzes the effect in a multimedia video streaming, i.e. peer-to-peer television (P2PTV), of a common traffic metric, i.e. packet losses, on the quality parameters, i.e. quality of service (QoS) and quality of experience (QoE). It introduces the more relevant works proposing QoE assessments. The chapter presents the overlay performanc...
Conference Paper
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 wid...
Article
The exponential growth of Internet traffic gives no respite to the telecommunications industry and is visibly shortening the life-cycle of the technologies used for core networking. To cope with the traffic demand, the industry has primarily focused on the evolution of the data and control planes, and has rapidly made progress in both subjects. How...
Article
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 produc...
Conference Paper
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 convention...
Chapter
Knowledge extraction is increasingly attracting the attention of researchers from different disciplines, as a means to automate complex tasks that rely on bulk textual resources. However, the configuration of many devices in the networking field continues to be a labor intensive task, based on the human interpretation and manual entry of commands t...
Conference Paper
The motivation behind the Locator/Identifier Separation Protocol (LISP) has shifted over time from routing scalability issues in the core Internet to a set of use cases for which LISP stands as a technology enabler. Among these are the mobility of physical and virtual appliances without breaking their TCP connections, seamless migration and fast de...
Conference Paper
There has been a wide shift in the way data are managed in the public administration. The move has led to an increased adoption of the Open Data model, where public administrations freely and openly publish data gathered using citizen taxes. However, undesirable side effects include the lack of data quality, incompatible formats and access methods,...
Article
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...
Conference Paper
Network coding has been recently proposed as a proactive network protection scheme. Its main objective is to improve the resilience of wired networks against link failures in a proactive manner, while simultaneously providing network resource savings (IP bandwidth, optical wavelengths) compared to traditional protection schemes. Warned by the poten...
Conference Paper
Full-text available
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...
Article
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 re...
Conference Paper
This paper outlines some promising results recently obtained in a field trial led by Telefónica and ADVA Optical Networking. The technology tested enables coordinated orchestrations among IP and transport management systems in multi-vendor settings.
Conference Paper
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 combina...
Conference Paper
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 p...
Conference Paper
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-us...
Conference Paper
Full-text available
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 b...
Article
For many years, the convergence of IP data services and transport network services based on optical transmission has been at the heart of carriers' investments and business strategies. However, significant challenges still remain. Over time, the inherent technological differences between the IP and transport networks have deeply segmented their ope...
Conference Paper
Full-text available
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 rout...
Conference Paper
Full-text available
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 a...
Conference Paper
Full-text available
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 end-users satisfaction level as the metric to perform the resource manage...
Conference Paper
Full-text available
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 traf...
Article
Full-text available
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 optic...
Conference Paper
Full-text available
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 prov...
Article
Full-text available
On-line end-to-end Service Level Agreement (SLA) monitoring is of key importance nowadays. For this purpose, recent researches have focused on measuring (when possible), or estimating (most of the times) network Quality of Service (QoS) and performance parameters. Up to now, all the proposed solutions have the drawback of requiring a huge amount of...
Conference Paper
Full-text available
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 fa...
Article
a b s t r a c t Traditional approaches to on-line end-to-end Service Level Agreement (SLA) assessment have focused on the estimation of network QoS parameters. These approaches, however, face a trade-off between accuracy and the amount of resources needed to achieve such accuracy. This paper offers an alternative approach, where instead of estimati...
Article
Full-text available
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 framewo...
Article
Full-text available
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 tec...
Conference Paper
Full-text available
The increase in multimedia content on the Internet has created a re- newed interest in quality assessment. There is however a main difference from the traditional quality assessment approaches, as now, the focus relies on the user per- ceived quality, opposed to the network centered approach classically proposed. In this paper we overview the most...
Article
Full-text available
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 tha...
Conference Paper
Full-text available
Management is a critical issue in optical networks. Highly impacting in management, routing in optical networks, is often decoupled into both the path selection and the wavelength assignment problems. In the former, shortest path based approaches are often applied to compute paths. Although such approaches offer advantages in terms of network loadi...
Conference Paper
Full-text available
On-line end-to-end Service Level Agreement (SLA) monitoring is of key importance nowadays. For this purpose, past recent researches focused on measuring (when possible) or estimating (most of the times) network QoS or performance parameters. Up to now, attempts to provide accurate techniques for estimating such parameters have failed. In addition,...
Conference Paper
Full-text available
New business infrastructures over the Internet pose a new set of traffic constraints. In particular, multimedia and interactive contents require guarantees of bandwidth and delivery time. The broad deployment and real-time nature of this class of applications require the provisioning of specific resources in the network to guarantee a certain level...
Conference Paper
Full-text available
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 lon...
Conference Paper
Full-text available
Packet losses are a critical metric for network performance assessment. In this paper we present a novel methodology to accurately estimate the packet loss ratio in realtime in a fully distributed scenario. The constraint such systems must face is the large amount of resources required for keeping live performance assessment. Our contribution has t...
Conference Paper
Full-text available
Multimedia and real-time services are spreading all over the Internet. The delivery quality of such contents is closely related to its network performance, for example in terms such as low latency or few packet losses. Both customers and operators want some feedback from the network in order to assess the real provided quality. There are proposals...
Conference Paper
Full-text available
Service providers' portfolio is continuously increasing with emerging real-time services, which are offered to current and new potential clients with an associated fee. In order to properly charge such a fee, both service providers and customers must have guarantees that the offered services are correctly delivered. One way of acquiring on-line inf...
Chapter
In order to support multimedia applications, a variety of QoS parameters must be supported for the respective data flows. These might include parameters such as delay, delay variation, bandwidth, jitter, packet loss etc., on the network level. Parameters can be defined on call (blocking probabilities, set-up latencies etc.) and user level (e.g., me...
Conference Paper
Full-text available
Real-time traffic is an important issue when designing networks. The growth in the deployment of voice applications in packet switched networks requires that the network can guarantee a minimum level of quality. At the same time, customers want guaranties that the proper quality of service is provided for their contracted services. In this environm...
Article
Full-text available
EuQoS is the acronym for "end-to-end quality of service support over heterogeneous networks", which is a European research project aimed at building an entire QoS framework, addressing all the relevant network layers, protocols, and technologies. This framework, which includes the most common access networks (xDSL, UMTS, WiFi, and LAN) is being pro...
Article
Full-text available
EuQoS is the acronym for “end-to-end quali-ty of service support over heterogeneous net-works,” which is a European research projectaimed at building an entire QoS framework,addressing all the relevant network layers, proto-cols, and technologies. This framework, whichincludes the most common access networks(xDSL, UMTS, WiFi, and LAN) is being prot...
Conference Paper
Full-text available
As Internet usage grows, more efforts are put in analysing its internal performance, usually such analysis comes through simulation using different models. While simulation can provide a good approximation of network behaviour, modeling such a complex network as the Internet is very difficult if not impossible. This paper studies the network's perf...
Article
Full-text available
As Internet usage grows, more efforts are put into analyzing its internal performance, usually such analysis comes through simulation using different models. While simulation can provide a good approximation of network behavior, modeling such a complex network as the Internet is very difficult if not impossible. This paper studies the network’s per...
Conference Paper
Full-text available
Fast Handovers is an enhancement to the Mobile IPv6 protocol, currently specified in an IETF draft, which reduces the handover latency. This can be beneficial to real-time applications. This paper presents a novel implementation of Fast Handovers and an analysis of the handover. Using a real testbed we study the handover latency and the provided Qo...
Conference Paper
Full-text available
This paper studies the problems related to mobile connectiv- ity on a wireless environment with Mobile IPv6, specially the handover, which is the most critical part. The main goal of this paper is to develop a structured methodology for analyzing 802.11/IPv6/MIPv6 handovers and their impact on application's level. This is accomplished by captur- in...
Article
Full-text available
This paper focuses on a measurement-based comparison of the handover for different mobility protocols: Mobile IPv4, Mobile IPv6 and Fast Handovers for Mobile IPv6. The paper studies the handover using active and passive measurements computing the handover latency, packet losses and the provided QoS level in a real testbed. Our experimental results...
Article
Full-text available
The fast evolution and increase in use of nowadays networks forces researchers to look for efficient ways of managing all the information that travels through those networks. Added to that, the growing use of Linux as main operating system for servers and big grid computing farms, has developed many research lines for increasing the networking capa...
Article
Full-text available
Multi-Protocol Label Switching (MPLS) has become the core switching infrastructure at the intra-domain level. However, little progress has been made to extend the reach of MPLS Label Switched Paths (LSPs) across domains. Among the problems that remain unsolved is how to efficiently find and establish primary and protection inter-domain LSPs for mis...
Article
Full-text available
Testing in real life conditions is not as easy as it first seems, because often it is costly and difficult to reproduce Internet behaviour in controlled environment. WAN Emulator (WANE) proposed herein is a software tool that helps controlling the IP traffic parameters of a network, like delay, packet loss or packet duplication.

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