Horizonte 2020 excelencia científica para el liderazgo europeo

La Unión Europea concentra gran parte de sus actividades de investigación e innovación en programas marco. Este año, y hasta 2020, entra en vigor el programa Horizonte 2020, sucesor del 7º Programa Marco. Entre sus objetivos figuran promover el liderazgo industrial europeo y reforzar la excelencia de su base científica. En la entrevista David Larrabeiti nos cuenta cómo se puede beneficiar la universidad y sus investigadores y que debe hacer la universidad para rentabilizar el programa

Signalling in voice over IP Networks

Voice signalling protocols have evolved, keeping with the prevalent move from circuit to packet switched networks. Standardization bodies have provided solutions for carrying voice traffic over packet networks while the main manufacturers are already providing products in workgroup, enterprise, or operator portfolio. This trend will accrue in next years due to the evolution of UMTS mobile networks to an “all-IP” environment. In this paper we present the various architectures that are proposed for signalling in VoIP, mainly: H.323, SIP and MGCP. We also include a brief summary about signalling in classical telephone networks and, at the end, we give some ideas about the proposed “all-IP” architectures in UMTS 3G mobile networks.Publicad

Multicast traffic aggregation in MPLS-based VPN networks

This article gives an overview of the current practical approaches under study for a scalable implementation of multicast in layer 2 and 3 VPNs over an IP-MPLS multiservice network. These proposals are based on a well-known technique: the aggregation of traffic into shared trees to manage the forwarding state vs. bandwidth saving trade-off. This sort of traffic engineering mechanism requires methods to estimate the resources needed to set up a multicast shared tree for a set of VPNs. The methodology proposed in this article consists of studying the effect of aggregation obtained by random shared tree allocation on a reference model of a representative network scenario.Publicad

A QoS-Driven ISP Selection Mechanism for IPv6 Multi-homed Sites

A global solution for the provision of QoS in IPng sites must include ISP selection based on per-application requirements. In this article we present a new site-local architecture for QoS-driven ISP selection in multi-homed domains, performed in a per application basis. This architecture proposes the novel use of existent network services, a new type of routing header, and the modification of address selection mechanisms to take into account QoS requirements. This proposal is an evolution of current technology, and therefore precludes the addition of new protocols, enabling fast deployment. The sitelocal scope of the proposed solution results in ISP transparency and thus in ISP independency.This research was supported by the LONG (Laboratories Over the Next Generation Networks) project IST-1999-20393.Publicad

A practical approach to network-based processing

The usage of general-purpose processors externally attached to routers to play virtually the role of active coprocessors seems a safe and cost-effective approach to add active network capabilities to existing routers. This paper reviews this router-assistant way of making active nodes, addresses the benefits and limitations of this technique, and describes a new platform based on it using an enhanced commercial router. The features new to this type of architecture are transparency, IPv4 and IPv6 support, and full control over layer 3 and above. A practical experience with two applications for path characterization and a transport gateway managing multi-QoS is described.Most of this work has been funded by the IST project GCAP (Global Communication Architecture and Protocols for new QoS services over IPv6 networks) IST-1999-10 504. Further development and application to practical scenarios is being supported by IST project Opium (Open Platform for Integration of UMTS Middleware) IST-2001-36063 and the Spanish MCYT under projects TEL99-0988-C02-01 and AURAS TIC2001-1650-C02-01.Publicad

Analysis of privacy vulnerabilities in single sign-on mechanisms for multimedia websites

This paper studies the privacy risks for the users of two popular single sign-on platforms for web-based content access: OpenID and Facebook Connect. In particular we describe in detail a privacy vulnerability of the OpenID Authentication Protocol that leads to the exposure of the OpenID user identifier to third parties. We illustrate how OpenID agents leak the (potentially unique) OpenID identifiers of their users to third parties, like advertisement and traffic analysis corporations. This vulnerability is a real and widespread privacy risk for OpenID users. This paper also analyzes the privacy of Facebook Connect --the proprietary single sign-on platform that is gaining a lot of popularity recently-- and, we conclude that it is not affected by the same vulnerability but other important privacy issues remain. Finally, this paper studies the solution space of these problems and defines a number of possible countermeasures. In the case of the OpenID vulnerability, we propose three solutions to this problem: one for the long term to avoid the root cause of the vulnerability, and another two short-term mitigations.The work presented in this paper has been funded by the INDECT project (Ref 218086) of the 7th EU Framework Programme.Publicad

Caracterización de los enlaces de Internet utilizando tecnología de redes activas

This paper presents the design, implementation and trials of a-clink, which is a hop-by-hop performance estimation tool based on active networks. The paper begins by analyzing different alternatives of hop-by-hop performance estimation tools: pathchar, clink, pchar and nettimer. Based on this analysis, several deficiencies are identified on the different tools. In order to improve the efficiency and accuracy of the estimations, one of the tools is selected, clink, to design an extension based active network technology. This extension, a-clink, has been implemented over the public domain active network platform SARA. The implementation of a-clink has been trialed on a simple active network prototype spanning two universities connected through public Internet, and its results compared with those obtained by the original clink. The paper concludes describing the advantages of the active version of clink over the conventional passive performance estimation tool.Publicad

A note on potential energy savings by extending the average cycle times in Passive Optical Networks

This work is at: 17th European Conference on Networks and Optical Communications 7th Conference on Optical Cabling and Infrastructure, took place Juny 20-22, 2012 in Vilanova i la Geltrú (Catalonia, Sapin).The web to event http://www.craax.upc.edu/noc2012/2/This article proposes a mechanism to increase the energy efficiency of the upstream channel in TDM-base PONs. Essentially, the ONUs are encouraged to accumulate traffic and transmit data bursts just by increasing the cycle time values artificially. The guard time is enlarged to avoid the case where ONUs are queried by the OLT and have none or few packets to transmit, thus allowing more time to sleep until the next cycle time. This strategy has however the downside effect of a substantial increase in the queueing delay experienced by packets. We provide a basic analysis to maximise the power savings for a given average delay target experienced by the packets.The authors would like to acknowledge the support to this work by the CAM-funded MEDIANET project, under code S-2009/TIC-1468.Publicad

Fronthaul network modeling and dimensioning meeting ultra-low latency requirements for 5G

Enabling the transport of fronthaul traffic in next-generation cellular networks [fifth-generation (5G)] following the cloud radio access network (C-RAN) architecture requires a redesign of the fronthaul network featuring high capacity and ultra-low latency. With the aim of leveraging statistical multiplexing gains, infrastructure reuse, and, ultimately, cost reduction, the research community is focusing on Ethernet-based packet-switch networks. To this end, we propose using the high queuing delay percentiles of the G/G/1 queuing model as the key metric in fronthaul network dimensioning. Simulations reveal that Kingman's exponential law of congestion provides accurate estimates on such delays for the particular case of aggregating a number of evolved Common Public Radio Interface fronthaul flows, namely functional splits Iu and IID. We conclude that conventional 10 G, 40 G, and 100 G transponders can cope with multiple legacy 10-20 MHz radio channels with worst-case delay guarantees. Conversely, scaling to 40 and 100 MHz channels will require the introduction of 200G, 400G, and even 1T high-speed transponders.The authors would like to acknowledge the support of the Spanish project TEXEO (grant no. TEC2016-80339-R), and the H2020 EU-funded project BlueSPACE (grant no. 762055)

Quasi-passive optical infrastructure for future 5G wireless networks: pros and cons

In this paper, we study the applicability of the quasi-passive reconfigurable (QPAR) device, a special type of quasi-passive wavelength-selective switch with flexible power allocation properties and no power consumption in the steady state, to implement the concept of reconfigurable backhaul for 5G wireless networks. We first discuss the functionality of the QPAR node and its discrete component implementation, scalability, and performance. We present a novel multi-input QPAR structure and the pseudo-passive reconfigurable (PPAR) node, a device with the functionality of QPAR but that is pseudo-passive during steady-state operations. We then propose mesh and hierarchical back-haul network architectures for 5G based on the QPAR and PPAR nodes and discuss potential use cases. We compare the performance of a QPAR-based single-node architecture with state-of-the-art devices. We find that a QPAR node in a hierarchical network can reduce the average latency while extending the reach and quality of service of the network. However, due to the high insertion losses of the current QPAR design, some of these benefits are lost in practice. On the other hand, the PPAR node can realize the benefits practically and is the more energy-efficient solution for high reconfiguration frequencies, but the remote optical node will no longer be passive. In this paper, we discuss the potential benefits and issues with utilizing a QPAR in the optical infrastructure for 5G networks.This work has been funded by the Spanish project TIGRE5 CM (grant number S2013/ICE 2919), the EU H2020 5G Crosshaul project (grant number 671598), and the Australian Research Council’s Discovery Early Career Researcher Award (DECRA) funding scheme (project number DE150100924). The authors would also like to acknowledge the support of the Center for Integrated Systems, Stanford University, and Corning Incorporated. for the development of this work