Jorge E. López de Vergara Méndez

Universidad Autónoma de Madrid | UAM · Department of Electronical and Communication Technology

In network management, it is important to model baselines, trends, and regular behaviors to adequately deliver network services. However, their characterization is complex, so network operation and system alarming become a challenge. Several problems exist: Gaussian assumptions cannot be made, time series have different trends, and it is difficult...

In an Internet arena where the search engines and other digital marketing firms' revenues peak, other actors have still open opportunities to monetize their users' data. After the convenient anonymization, aggregation, and agreement, the set of websites users visits may result in exploitable data for ISPs. Uses cover from assessing the scope of adv...

Near-lossless compression is a generalization of lossless where the codec user is able to set the maximum absolute difference (the error tolerance) between the values of an original pixel and the decoded one. This enables higher compression ratios, while still allowing to control the bounds of the quantization errors in the space domain. This featu...

Web browsing privacy is a matter of paramount importance for the Internet users. While they try to protect themselves from being monitored by getting advantage of encryption or VPNs, users' privacy is still unaccomplished, even taking into account the tangled web, with several domains visited at the same time in a single web page, or IP addresses o...

Server load estimation is key in balancing traffic between servers when optimizing data center resources. Intrusive methods are sometimes difficult or impossible to implement. Therefore, non-intrusive estimation methods are the best alternative in these cases. The objective of this paper is to present a server load estimation method based on extern...

Ambiguous Read-after-Write (RAW) dependencies are omnipresent in multiple streaming applications, establishing hard to optimize bottlenecks. Considering actual input data, these may rarely be true dependencies. However, the increasingly used High-Level Synthesis (HLS) compilers must assume the worst-case scenario, as they rely on static optimizatio...

Traffic classification is one of the most important challenges for both Internet service providers and users, because the right use of traffic policing and planning allows for proper optimization of network resources. However, there is no perfect solution for this problem, due to the grade of complexity that modern traffic has achieved. Using convo...

The H2020 METRO-HAUL European project has architected a latency-aware, cost-effective, agile, and programmable optical metro network. This includes the design of semidisaggregated metro nodes with compute and storage capabilities, which interface effectively with both 5G access and multi-Tbit/s elastic optical networks in the core. In this paper, w...

The H2020 METRO-HAUL European project has architected a latency-aware, cost-effective, agile, and programmable optical metro network. This includes the design of semi-disaggregated metro nodes with compute and storage capabilities, which interface effectively with both 5G access and multi-Tbit/s elastic optical networks in the core. In this paper,...

In this work, we present and evaluate a hardware architecture for the LOCO-ANS (Low Complexity Lossless Compression with Asymmetric Numeral Systems) lossless and near-lossless image compressor, which is based on JPEG-LS standard. The design is implemented in two FPGA generations, evaluating its performance for different codec configurations. The te...

Web browsing analytics provides insights on the websites that users access. Although this might be seen as an easy task, different problems, such as encryption or the tangled web, with several domains visited at the same time in a single web page, or IP addresses of a cloud provider shared by several sites, make it a though job. However, despite th...

We report the automated deployment of 5G services across a latency-aware, semidisaggregated, and virtualized metro network. We summarize the key findings in a detailed analysis of end-to-end latency, service setup time, and soft-failure detection time.

We report the automated deployment of 5G services across a latency-aware, semi-disaggregated, and virtualized metro network. We summarize the key findings in a detailed analysis of end-to-end latency, service setup time, and soft-failure detection time.

Periods of low load have been used for the scheduling of non-interactive tasks since the early stages of computing. Nowadays, the scheduling of bulk transfers-i.e., large-volume transfers without precise timing, such as database distribution, resources replication or backups-stands out among such tasks, given its direct effect on both the performan...

In this paper, we show that server load correlates with TCP SYN response time (SRT), that is, the time from SYN to SYN+ACK segments at the server side. For this, it applies the innovative approach of modeling the SRT with an appropriate α-stable heavy tail distribution. We also show that α-stable distribution parameters are related to the server lo...

The automation of Network Services (NS) consisting of virtual functions connected through a multilayer packet-over-optical network requires predictable Quality of Service (QoS) performance, measured in terms of throughput and latency, to allow making proactive decisions. QoS is typically guaranteed by overprovisioning capacity dedicated to the NS,...

Video streaming over IP networks presents several challenges for remote drone piloting. To achieve a high Quality of Experience, minimal latency is mandatory. However, wireless links usually impose dynamic changes to Quality of Service conditions. Moreover, bandwidth limitations can increase both the final perceived latency and packet loss during v...

El análisis de los estadísticos del tráfico en una red permite caracterizarlo, hasta el punto de poder identificar los ataques utilizando ajustes estadísticos de series temporales con distribuciones α-estables. Otras técnicas se basan en la detección de mesetas, pero si el ataque no las genera, no son eficaces. En el presente artículo se presenta u...

In this paper, a longitudinal study is presented about the score reliability in continuous assessment tests of the subject Network Architecture II, which is taught in the Telecommunication Technologies and Services Engineering degree, offered at Universidad Autónoma de Madrid, Spain. It is important to evaluate if scores in tests are reliable, beca...

New techniques, based on Software-Defined Networks, are used to deploy optical paths dynamically. This demonstration shows how active measurements at 100 Gbit/s are performed to check before operation that the performance requirements are met in terms of capacity, delay or packet loss.

Slides of the demonstration.

New techniques, based on Software-Defined Networks, are used to deploy optical paths dynamically. This demonstration shows how active measurements at 100 Gbit/s are performed to check before operation that the performance requirements are met in terms of capacity, delay or packet loss.

Many network management actions need a simultaneous consideration of several elements' state. This is becoming an even more complex matter with the advent of reconfigurable deployments, where scaling functions up can prevent performance bottlenecks. Therefore, fine-grained detection of significant burdens arises as a cornerstone to optimize their m...

Este póster presenta los resultados derivados del desarrollo y uso de nuevos recursos docentes de autoevaluación de los contenidos teóricos de la asignatura mediante el uso de tests de Moodle, así como la gamificación del refuerzo de conceptos prácticos mediante el uso de Kahoot. Las innovaciones se plantearon dentro del proyecto “Mejora de los re...

In this paper, a longitudinal study is presented about the score reliability in continuous assessment tests of the subject Network Architecture II, which is taught in the Telecommunication Technologies and Services Engineering degree, offered at Universidad Autónoma de Madrid, Spain. It is important to evaluate if scores in tests are reliable, beca...

Presentation given at the MetroHaul workshop within NGON. The presentation shows the experience of defining and maintaining a YANG model at IETF.

This paper introduces the first flow exporter architecture based on a stand-alone FPGA, designed for the aggregation and subsequent exportation of TCP sessions records for 100 GbE links, assuring peak performance without packet sampling even at the maximum packet rate. Our research shows that FPGA fabric offers adequate flexibility and performance...

Incoming 5G networks will evolve regarding how they operate due to the use of virtualization technologies. Network functions that are necessary for communication will be virtual and will run on top of commodity servers. Among these functions, it will be essential to deploy monitoring probes, which will provide information regarding how the network...

Internet measurement and analysis is a never-ending challenge that increases in difficulty every year with the network evolution. This transformation affects the analysis in different ways, like changing-trends, speed increments or new protocols and ciphers. One possible solution is to use very large dedicated and expensive monitoring equipment. As...

In this demo, we present an end-to-end video transmission system, using the low-end ZynqBerry board. In the programmable logic we have developed an efficient hardware implementation of a video encoder optimized for ultra low-latency, using the Logarithmic Hop Encoding (LHE) algorithm, which works in the time domain, meaning that no domain transform...

Virtualization and emulation have become worthy approaches to save humongous amounts of money related to physical resource acquisition expenditures. In this light, the development of network emulation platforms has led a revolution in the research and testing of novel services and applications, as they provide a cost-effective, flexible and reprodu...

In this paper we analyze the performance issues involved in the generation of automated traffic reports for large IT infrastructures. Such reports allow the IT manager to proactively detect possible abnormal situations and roll out the corresponding cor-rective actions. With the ever-increasing bandwidth of current networks, the design of automated...

Many management actions for networking infrastructures require to simultaneously consider the state of several network elements. This is particularly critical in the case of reconfigurable deployments, such as Virtual or Software-Defined Networks, to scale the affected equipment up and prevent performance bottlenecks. In this light, we present dPRI...

En este trabajo se presenta una arquitectura basada en FPGA, diseñada para la agregación y posterior exportación de registros de sesiones TCP en enlaces de hasta 40 Gbit/s sin realizar muestreo de paquetes, incluso a la máxima tasa de paquetes. De esta manera, se descarga a exportadores de flujos basados en hardware de propósito específico de tarea...

Online Quality of Service (QoS) assessment in high speed networks is one of the key concerns for service providers, namely to detect QoS degradation on-the-fly as soon as possible and avoid customers’ complaints. In this regard, a Key Performance Indicator (KPI) is the number of TCP retransmissions per flow, which is related to packet losses or inc...

In this paper, we present an efficient hardware implementation of a video encoder optimized for ultra low-latency, using the Logarithmic Hop Encoding algorithm. This design provides the following features: (i) A maximum marginal output latency of 23 clock cycles, (ii) small area requirements, (iii) proven rate up to 95 Millions of pixels per second...

New Ethernet standards, such as 40 GbE or 100 GbE, are already being deployed commercially along with their corresponding Network Interface Cards (NICs) for the servers. However, network measurement solutions are lagging behind: while there are several tools available for monitoring 10 or 20 Gbps networks, higher speeds pose a harder challenge that...

Bandwidth verification in shaping scenarios receives much attention of both operators and clients because of its impact on Quality of Service (QoS). As a result, measuring shapers' parameters, namely the Committed Information Rate (CIR), Peak Information Rate (PIR) and Maximum Burst Size (MBS), is a relevant issue when it comes to assess QoS. In th...

CASTOR architecture to enable cognitive networking is demonstrated. Extended nodes make local decisions, whilst a centralized system beside the network controller makes network-wide decisions. Interaction with ONOS, Net2Plan, and passive monitoring devices is exhibited.

In many optical network scenarios, such as Storage Array Network (SAN) replication, keeping latency under control is cornerstone to provide a proper Quality of Service (QoS). Hence, measuring latencies in such optical networks becomes fundamental. However, for low distances, microseconds resolution is required, which, in turn, demands ad-hoc hardwa...

The lack of privileged access to emergent and operational deployments is one of the key matters during validation and testing of novel telecommunication systems and technologies. This matter jeopardizes the repeatability of experiments, which results in burdens for innovation and research in these areas. In this light, we present a method and archi...

Wireless access technologies are widespread in domestic scenarios, and end users extensively use mobile phones or tablets to browse the Web. Therefore, methods and platforms for the measurement of network key performance indicators must be adapted to the peculiarities of this environment. In this light, the experiments should capture the true condi...

Nowadays, the demand of Over-The-Top (OTT) services such as multimedia streaming, web services or social networking is rapidly increasing. Consequently, there is a wide interest in studying the quality of these services so that Internet Service Providers (ISP) can deliver the best experience to their clients.For this purpose, we present FlexiTop, a...

Current fixed and mobile networks’ behavior is rapidly changing, which calls for flexible monitoring approaches to avoid loosing track with such a fast evolutionary pace. Due to the many challenges that this scenario is posing to network managers, we propose the exploration of Functional Data Analysis (FDA) techniques as a mean to easily deal with...

Analyzing multi-Gb/s links is a very tough task. Classical solutions to overcome this problem used different sampling methods. However, keeping traffic information at 100 Gb/s and higher data rates becomes very difficult. Current Big Data-based architectures are very inefficient in terms of resource management and rely on suboptimal programming lan...

En la actualidad, la proliferación de dispositivos móviles y accesos a Internet utilizando tecnologías inalámbricas en los entornos domésticos obliga a cambiar las metodologías para la realización de medidas de red.Para que éstas representen fidedignamente las condiciones ofrecidas a los usuarios, las prestaciones del equipamiento de medida y el nú...

En este artículo se realiza un estudio longitudinal de las calificaciones de evaluación continua de la asignatura Arquitectura de Redes II, del Grado en Ingeniería de Tecnologías y Servicios de Telecomunicación que se oferta en la Universidad Autónoma de Madrid. Para ello se analizan las calificaciones obtenidas en los veinte controles realizados d...

Hoy en día, el uso de los servicios Over-The-Top tales como streaming de vídeo, servicios web y redes sociales es dominante en el tráfico de Internet. En consecuencia, existe un amplio interés por parte de los proveedores de servicios de Internet (Internet Service Providers, ISP) en conocer la calidad de este tipo de comunicaciones para poder propo...

Un problema recurrente para los profesionales de la Ingeniería Telemática es la escasez de despliegues de tecnologías emergentes y las restricciones de acceso a redes operativas. Por ello, en este trabajo presentamos un método para la generación automática de carga siguiendo perfiles de actividad que facilita la replicación del comportamiento típic...

alpha-stable distributions are a family of probability distributions found to be suitable to model many complex processes and phenomena in several research fields, such as medicine, physics, finance and networking, among others. However, the lack of closed expressions makes their evaluation analytically intractable, and alternative approaches are c...

This document defines a YANG model for managing flexi-grid optical networks. The model described in this document defines a flexi-grid traffic engineering database. A complementary module is referenced to detail the flexi-grid media channels. This module is grounded on other defined YANG abstract models.

This document defines a YANG model for managing flexi-grid optical media channels, complementing the information provided by the flexi-grid TED model. It is also grounded on other defined YANG abstract models.

An architecture supporting the OAA loop is proposed. It consists on extending nodes and the domain controller with analytics capabilities for local and network-wide operation automation. The architecture is experimentally assessed through a use case.

This poster includes a summary of the results of the two first years of my Ph.D. project. We thank the TMA organization committee for awarding me a STG to attend this event.

Communication networks these days face a relentless increase in traffic load. Multi-gigabitper- second links are becoming widespread, and network devices are under continuous stress, so testing whether they guarantee the specified throughput or delay is a must. Software-based solutions, such as packet-train traffic injection, were adequate for lowe...

This presentation includes the description of Dictyogram, a method and technique intended to make easier the visualization and understanding of network flows. The full paper (doi:10.1109/CNSM.2015.7367362), which presents further details and discussion about our solution, can be accessed at our ResearchGate profiles.

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...

This paper presents the challenges and purpose of building the Traffic Engineering Database (TED) to facilitate Software Defined control of an Elastic Optical Network (EON). It explains how a standardized protocol and data model can facilitate this and describes a YANG model that has been developed to represent the TED including the representation...

Network Management tasks are currently characterized by their diversity both in terms of the situations that must be faced and the data used to reach conclusions. This complex and changing context imposes diverse needs and restrictions that must be covered by management tools in order for them to be useful. In order to face current challenges, we p...

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...

In this poster, we presented some preliminary results related to my Ph.D. project. We thank the Organizing committee of TMA for awarding me a STG to attend this event.

The rise of network speeds to tens of gigabits per second poses a challenge to develop packet processing applications that can cope with such bit rates. Therefore, the need for a suitable open source system that can be used as a prototype platform to test new network functionality while ensuring line-rate processing, accurate timestamping, and redu...