Convergencia de tecnologías ópticas y Ethernet en LAN, MAN y SAN: nuevas arquitecturas, análisis de prestaciones y eficiencia energética

Mención Internacional en el título de doctorThe development of Information Technologies in the last decades, especially the last two, together with the introduction of computing devices to the mainstream consumer market, has had the logical consequence of the generalisation of the Internet access. The explosive development of the smartphone market has brought ubiquity to that generalisation, to the point that social interaction, content sharing and content production happens all the time. Social networks have all but increased that trend, maximising the diffusion of multimedia content: images, audio and video, which require high network capacities to be enjoyed quickly. This need for endless bandwidth and speed in information sharing brings challenges that affect mainly optical Metropolitan Area Networks (MANs) and Wide Area Networks (WANs). Furthermore, the wide spreading of Ethernet technologies has also brought the possibility to achieve economies of scale by either extending the reach of Ethernet Local Area Networks (LANs) to the MAN and WAN environment or even integrating them with Storage Area Networks (SANs). Finally, this generalisation of telecommunication technologies in every day life has as a consequence an important rise in energy consumption as well. Because of this, providing energy efficient strategies in networking is key to ensure the scalability of the whole Internet. In this thesis, the main technologies in all the fields mentioned above are reviewed, its core challenges identified and several contributions beyond the state of the art are suggested to improve today’s MANs andWANs. In the first contribution of this thesism, the integration between Metro Ethernet and Wavelength Division Multiplexion (WDM) optical transparent rings is explored by proposing an adaptation architecture to provide efficient broadcast and multicast. The second contribution explores the fusion between transparent WDM and OCDMA architectures to simplify medium access in a ring. Regarding SANs, the third contribution explores the challenges in SANs through the problems of Fibre Channel over Ethernet due to buffer design issues. In this contribution, analysis, design and validation with FCoE traces and simulation is provided to calculate buffer overflow probabilities in the absence of flow control mechanisms taking into account the bursty nature of SAN traffic. Finally, the fourth and last contribution addresses the problems of energy efficiency in Plastic Optical Fibres (POF), a new kind of optical fibre more suitable for transmission in vehicles and for home networking. This contribution suggests two packet coalescing strategies to further improve the energy effiency mechanisms in POFs.El desarrollo de las Tecnologías de la Información en las últimas décadas, especialmente las últimas dos, junto con la introducción de dispositivos informáticos al mercado de masas, ha tenido como consecuencia lógica la generalización del acceso a Internet. El explosivo desarrollo del mercado de teléfonos inteligentes ha añadido un factor de ubicuidad a tal generalización, al extremo de que la interacción social, la compartición y producción de contenidos sucede a cada instante. Las redes sociales no han hecho sino incrementar tal tendencia, maximizando la difusión de contenido multimedia: imágenes, audio y vídeo, los cuales requieren gran capacidad en las redes para poder obtenerse con rapidez. Esta necesidad de ancho de banda ilimitado y velocidad en la compartición de información trae consigo retos que afectan principalmente a las Redes de Área Metropolitana (Metropolitan Area Networks, MANs) y Redes de Área Extensa (Wide Area Networks, WANs). Además, la gran difusión de las tecnologías Ethernet ha traído la posibilidad de alcanzar economías de escala bien extendiendo el alcance de Ethernet más allá de las Redes de Área Local (Local Area Networks, LANs) al entorno de las MAN y las WAN o incluso integrándolas con Redes de Almacenamiento (Storage Area Networks, SANs). Finalmente, esta generalización de las tecnologías de la comunicación en la vida cotidiana tiene también como consecuencia un importante aumento en el consumo de energía. Por tanto, desarrollar estrategias de transmisión en red eficientes energéticamente es clave para asegurar la escalabilidad de Internet. En esta tesis, las principales tecnologías de todos los campos mencionados arriba serán estudiadas, sus más importantes retos identificados y se sugieren varias contribuciones más allá del actual estado del arte para mejorar las actuales MANs y WANs. En la primera contribución de esta tesis, se explora la integración entre Metro Ethernet y anillos ópticos transparentes por Multiplexión en Longitud de Onda (Wavelength Division Multiplex, WDM) mediante la proposición de una arquitectura de adaptación para permitir la difusión y multidifusión eficiente. La segunda contribución explora la fusión entre las arquitecturas transparentes WDM y arquitecturas por Accesso Dividido Múltiple por Códigos Ópticos (OCDMA) para simplificar el acceso en una red en anillo. En lo referente a las SANs, la tercera contribución explora los retos en SANs a través de los problemas de Fibre Channel sobre Ethernet debido a los problemas en el diseño de búferes. En esta contribución, se provee un análisis, diseño y validación con trazas FCoE para calcular las probabilidades de desbordamiento de buffer en ausencia de mecanismos de control de flujo teniendo en cuenta la naturaleza rafagosa del tráfico de SAN. Finalmente, la cuarta y última contribución aborda los problemas de eficiencia energética en Fibras Ópticas Plásticas (POF), una nueva variedad de fibra óptica más adecuada para la transmisión en vehículos y para entornos de red caseros. Esta contribución sugiere dos estrategias de agrupamiento de paquetes para mejorar los mecanismos de eficiencia energética en POFs.Programa Oficial de Posgrado en Ingeniería TelemáticaPresidente: Luca Valcarenghi.- Secretario: Ignacio Soto Campos.- Vocal: Bas Huiszoo

Packet Coalescing Strategies for Energy Efficient High-Speed Communications Over Plastic Optical Fibers

Many recent standards for wireline communications have included a low-power operation mode for energy efficiency purposes. The recently approved VDE standard 0885-763-1 for high-speed communication over plastic optical fibers has not been an exception. The lowpower mode is used when there is no data to be transmitted over the line, thus making consumption more proportional to network load. Furthermore, packet coalescing has been proposed in the literature to minimize the transitions between the low-power and active modes, thus reducing the energy penalties associated with such transitions. This article proposes an adapted version of packet coalescing for the periodic structure of the VDE 0885-763-1 physical layer. Such an algorithm attempts to fulfill active periods of transmission with data, showing an improved energy efficiency over conventional packet coalescing strategies. This conclusion is evaluated via simulation with both synthetic Poissonian traffic and real traces.The authors would like to thank K. Fu, G. Chesson, L. A. Barroso, and U. Holzle from Google for the anonymous traces from their data centers used in the experiment section. The authors would also like to acknowledge the Spanish-funded CRAMNET project (grant number TEC2012-38362-C03-01) for its support to the development of this work

On Providing Metro Ethernet Services over Transparent WDM Optical Rings

The long list of benefits (especially cost and capacity) of Ethernet LANs has made the IEEE, the ITU-T, and the Metro Ethernet Forum define the requirements for taking Ethernet beyond the local area, toward the metropolitan region. In addition, the ever-increasing traffic demands of new applications and users can only be met by the huge bandwidth capacity provided by optical fibers. This work studies how to provide metro Ethernet services over transparent tunable-transmitter fixed-receiver WDM optical ring networks. A new adaptation layer of ME to WDM is proposed, and its benefits and drawbacks are studied. It is shown that such a transparent WDM ring network can be seen as a logical full-mesh topology by the upper ME layer, thus reducing to one the number of optical-electronic-optical conversions per unicast frame. Additionally, two different approaches are proposed in the case of broadcast/multicast traffic, since this may bring scalability difficulties in ring topologies.The work described in this article was carried out with the support of the Building the Future Optical Network in Europe (BONE) project, a Network of Excellence funded by the European Commission through the 7th ICT-Framework Programme. Additionally, the authors are thankful for the support of the T2C2 (grant TIN2008-06739C04-01) and MEDIANET (grant S2009/TIC-1468) projects for the development of this work.European Community's Seventh Framework ProgramPublicad

Digital Wiretap Warrant: Improving the security of ETSI Lawful Interception

Lawful Interception (LI) of data communications is an essential tool for Law Enforcement Agencies (LEA) in order to investigate criminal activities carried out or coordinated by means of Internet. However, the ability to secretly monitor the activities of citizens also has a great impact on civil rights. Therefore, democratic societies must prevent abuse and ensure that LI is only employed in specific cases with justifiable grounds or a probable cause. Nowadays, in many countries each interception must be authorized by a wiretap warrant, usually issued by a judge. However, this wiretap warrant is merely an administrative document that should be checked by the network or service operator before enabling the monitoring of its customers, whose communications are later handed over to a LEA in plaintext. This paper proposes the idea of employing a Digital Wiretap Warrant (DWW), which further protects the civil liberties, security and privacy of LI by ensuring that monitoring devices can only be enabled with a valid DWW, and by encrypting the captured data so only the authorized LEA is able to decrypt those communications. Moreover, in the proposed DWW framework all digital evidence is securely time-stamped and signed, thus guaranteeing that it has not been tampered with, and that a proper chain of custody has been met. In particular this paper proposes how to apply the DWW concept to the lawful interception framework defined by the ETSI LI Technical Committee, and evaluates how the additional security mechanisms could impact the performance and storage costs of a LI platform.The work presented in this paper has been funded by the INDECT project (Ref 218086) of the 7th EU Framework Programme. The authors would also like to acknowledge the Spanish-funded CRAMnet (Grant no. TEC2012-38362-C03-01)

Integrating a next-generation optical access network testbed into a large-scale virtual research testbed

Several experimental research networks have been created in the laboratories of prominent universities and research centres to assess new optical communication technologies. A greater value and research impact can be obtained from these testbeds by making them available to other researchers through research infrastructure federations such as GENI and/or FIRE. This is a challenging task due to the limitations of programmability of resource management and virtualisation software in most experimental optical networks. Fed4FIRE is an EU research project that makes it possible to create complex testbed scenarios that interconnect heterogeneous testbeds distributed physically all over the world. In this paper, we present a practical approach for the federation of a next-generation optical access testbed created at Stanford University called UltraFlow Access. That testbed offers its users both packet-switched and circuit-switched services while remaining compatible with conventional PONs. Our approach facilitates experimentation on the UltraFlow Access testbed in the context of large virtual testbeds using Fed4FIRE protocols.The research of this paper was partially financed by the European Union’s FP7 grant agreement no. 318389 Fed4FIRE Project, the National Science Foundation (grant no. 111174), NSERC, the Spanish projects CRAMnet (grant no. TEC2012-38362-C03- 01) and TIGRE5-CM (grant no. S2013/ICE-2919). The authors would also like to acknowledge the support of the Chair of Excellence of Bank of Santander at UC3M.European Community's Seventh Framework Progra

Study of a hybrid OCDMA-WDM segmented ring for metropolitan area networks

Proceeding of: 12th International Conference on High Performance Switching and Routing, Cartagena, Spain, July 4-6, 2011Optical Code Division Multiple Access (OCDMA) techniques have shown outstanding capabilities in the sharing of optical media, in particular in access networks. However, OCDMA systems may suffer from Multiple Access Interference (MAI) and other kinds of noise when many users access the shared media simultaneously, increasing the BER (Binary Error Rate) to unacceptable levels, that is, a situation at which all combined signals interfere and are lost. This work proposes a mixed OCDMA and Tunable Transmitter- Fixed Receiver (TT-FR) WDM and ring architecture at which the ring is split into small-size segments to limit the probability of MAI. Essentially, every segment in the ring has got two hub nodes (on the segment’s head and tail) which forwards inter-segment traffic to other hub nodes on dedicated home wavelengths, thus making use of WDM. The access media inside the segment is shared between the nodes by means of OCDMA, and code reuse is possible on different segments. Our performance analysis shows how to split a given ring into segments in order to minimise the BER due to multiple users accessing the network and allow for high bit-rates for a given traffic load. In addition, we analyse the possibility of introducing Forward Error Correction (FEC) at a moderate overhead cost to improve performance.The work described in this paper was carried out with the support of the BONE project (“Building the Future Optical Network in Europe”), a Network of Excellence funded by the European Commission through the 7th ICT-Framework Programme. Additionally, the authors would like to thank the support of the T2C2 Spanish project (under code TIN2008-06739-C04-01) and the Greencom UC3M-CAM project under code (CCG10-UC3M/TIC-5624).Publicad

A Bloom Filter-Based Monitoring Station for a Lawful Interception Platform

Lawful Interception (LI) is a fundamental tool in today's Police investigations.Therefore, it is important to make it as quickly and securely as possible as well as a reasonable cost per suspect. This makes traffic capture in aggregation links quite attractive, although this implies high wirespeeds which require the use of specific hardware-based architectures. This paper proposes a novel Bloom Filter-based monitoring station architecture for efficient packet capture in aggregation links. With said Bloom filter, we filter out most of the packets in the link and capture only those belonging to lawful interception wiretaps. Next, we present an FPGA-based implementation of said architecture and obtain the maximum capture rate achievable by injecting traffic through four parallel Gigabit Ethernet lines. Finally, we identify the limitations of our current design and suggest the possibility of further extending it to higher wirespeeds.- Best Paper AwardThe work presented in this paper has been funded by the INDECT project grant number FP7-ICT-218086, and the Spanish CramNet project (grant no. TEC2012-38362-C03-01).European Community's Seventh Framework Progra

Experimenting the integration of green optical access and metro networks based on SDN

This paper outlines the issues in providing a seamless integration between energy-efficient optical access networks and metro networks that preserves the overall latency balance. A solution based on SDN is proposed and detailed. The proposed solution allows to trade the increased delay in the access section, due the utilization of energy efficient schemes, with a reduced delay in the metro section. Experiments in a geographically distributed testbed evaluate the different delay contributions.This work was carried out with the support of the Fed4FIRE project (“Federation for FIRE”), an integrated project funded by the European Commission through the 7th ICT Framework Programme (318389).European Community's Seventh Framework Progra