Aracil Rico, Javier

person.page.identifierURI

https://academica-e.unavarra.es/handle/2454/48552

Last Name

Aracil Rico

First Name

Javier

person.page.departamento

Automática y Computación

person.page.observainves

1175081

person.page.upna

1977

Full item page

Search Results

Now showing 1 - 10 of 30

Open Access
Online detection of pathological TCP flows with retransmissions in high-speed networks
(Elsevier, 2018) Miravalls-Sierra, Eduardo; Muelas, David; Ramos, Javier; López de Vergara, Jorge E.; Morató Osés, Daniel; Aracil Rico, Javier; Automática y Computación; Automatika eta Konputazioa
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 increased network and/or client/server latency. However, to accurately detect TCP retransmissions the whole sequence number list should be tracked which is a challenging task in multi-Gb/s networks. In this paper we show that the simplest approach of counting as a retransmission a packet whose sequence number is smaller than the previous one is enough to detect pathological flows with severe retransmissions. Such a lightweight approach eliminates the need of tracking the whole TCP flow history, which severely restricts traffic analysis throughput. Our findings show that low False Positive Rates (FPR) and False Negative Rates (FNR) can be achieved in the detection of such pathological flows with severe retransmissions, which are of paramount importance for QoS monitoring. Most importantly, we show that live detection of such pathological flows at 10 Gb/s rate per processing core is feasible.
Open Access
Delay-throughput curves for timer-based OBS burstifiers with light load
(IEEE, 2006) Izal Azcárate, Mikel; Aracil Rico, Javier; Morató Osés, Daniel; Magaña Lizarrondo, Eduardo; Automática y Computación; Automatika eta Konputazioa
The OBS burstifier delay-throughput curves are analyzed in this paper. The burstifier incorporates a timer-based scheme with minimum burst size, i. e., bursts are subject to padding in light-load scenarios. Precisely, due to this padding effect, the burstifier normalized throughput may not be equal to unity. Conversely, in a high-load scenario, padding will seldom occur. For the interesting light-load scenario, the throughput delay curves are derived and the obtained results are assessed against those obtained by trace-driven simulation. The influence of long-range dependence and instantaneous variability is analyzed to conclude that there is a threshold timeout value that makes the throughput curves flatten out to unity. This result motivates the introduction of adaptive burstification algorithms, that provide a timeout value that minimizes delay, yet keeping the throughput very close to unity. The dependence of such optimum timeout value with traffic long-range dependence and instantaneous burstiness is discussed. Finally, three different adaptive timeout algorithms are proposed, that tradeoff complexity versus accuracy.
Open Access
A-priori flow bandwidth estimates for dynamic bandwidth allocation in ISP access links
(2001) Aracil Rico, Javier; Morató Osés, Daniel; Automática y Computación; Automatika eta Konputazioa
In this paper we study a-priori bandwidth estimation algorithms for TCP flows. An RTT-based bandwidth allocator is proposed, which outperforms a broad class of peak-rate and static allocation flow switching solutions. Our findings suggest that a-priori bandwidth estimation (i.e, before the TCP data transfer phase takes place) is indeed feasible and serves to design simple, yet efficient, dynamic bandwidth allocation rules for ISP access links.
Open Access
Técnicas eficientes de filtrado y análisis de tráfico para la monitorización continua de redes de comunicaciones
(1999) Ruiz, José Javier; Magaña Lizarrondo, Eduardo; Aracil Rico, Javier; Villadangos Alonso, Jesús; Automática y Computación; Automatika eta Konputazioa
This paper presents an efficient traffic filtering and analysis architecture for network monitoring. Opposed to the usual network monitoring architectures that provide simultaneous filters as requested by managers (packet filters), we propose a different approach that aims at minimizing CPU load by avoiding unnecessary filter duplicates. Such architecture makes it possible to optimize several parallel filters execution and thus is suitable for continuous network monitoring in which it is necessary to keep track of hundreds of filters. This architecture has been implemented in a network-monitoring tool called PROMIS whose main features are detailed in this paper.
Open Access
Predicción de tráfico de Internet and aplicaciones
(2001) Bernal, I.; Aracil Rico, Javier; Morató Osés, Daniel; Izal Azcárate, Mikel; Magaña Lizarrondo, Eduardo; Díez Marca, L. A.; Automática y Computación; Automatika eta Konputazioa
In this paper we focus on traffic prediction as a means to achieve dynamic bandwidth allocation in a generic Internet link. Our findings show that coarse prediction (bytes per interval) proves advantageous to perform dynamic link dimensioning, even if we consider a part of the top traffic producers in the traffic predictor.
Open Access
Internet traffic shaping for IP over WDM links with source output buffering or multiple parallel wavelengths
(Kluwer Academic Publishers, 2001) Aracil Rico, Javier; Izal Azcárate, Mikel; Morató Osés, Daniel; Automática y Computación; Automatika eta Konputazioa
Since the number of wavelengths per fiber is growing in an exponential fashion the over- flow traffic can be routed through overflow lightpaths, thus providing an ideal network with near-infinite capacity and almost no-buffering. Such unprecedented bandwidth growth in the network backbone is only limited by the processing speed of the electronic elements. Even though multiple parallel high-speed channels (lightpaths) are provided between IP routers the switching speed of the latter is an order of magnitude below the lightpath transmission speed. As a result, minimizing transfer delay is not only a matter of forwarding traffic as fast as possible but to shape traffic so that the input queues of the destination routers do not over-flow. Even though it is desirable to exploit the WDM capabilities to forward traffic in parallel channels in order to nearly eliminate the router output buffering, it turns out that the extreme burstiness of Internet traffic is even increased by routing part of the traffic through a backup channel. Instead, the use of source output buffering for traffic shaping purposes proves more beneficial. In this paper, we examine the typical scenario of a static WDM network with several wavelengths between IP routers. In a simple configuration of a primary and over flow lightpath the results show that if 3% of the traffic is routed through the over flow lightpath then the packet forwarding speed in the destination router should be increased in 20% in order to obtain the same transfer delay as with the single lightpath configuration with source output buffering.
Open Access
Use of CBR for IP over ATM
(SPIE, 1997) Aracil Rico, Javier; Morató Osés, Daniel; Izal Azcárate, Mikel; Donézar, C.; Automática y Computación; Automatika eta Konputazioa
Internet traffic burstiness allows for statistical multiplexing gain in the available bandwidth of an ATM link. However, a dynamic allocation bandwidth assignment (ABR) has to be performed. In this paper we evaluate the real advantages of ABR versus CBR for Internet service provisioning. We consider performance parameters such as connection setup delay and active waiting time due to flow control and show that CBR schemes can be a good alternative for Internet service provisioning over ATM networks.
Open Access
Blocking time analysis of OBS routers with arbitrary burst size distribution
(IEEE, 2003) Morató Osés, Daniel; Izal Azcárate, Mikel; Aracil Rico, Javier; Magaña Lizarrondo, Eduardo; Miqueleiz Alamos, J.; Automática y Computación; Automatika eta Konputazioa
The blocking time distribution for an OBS router is obtained, under the assumption of Poisson-arriving bursts with Pareto, Gaussian and Exponential burst size distributions. Analytical expressions are provided as a function of number of wavelengths per port. Such expressions can be used to dimension Fiber Delay Lines (FDLs) and to perform end-to-end delay estimation. On the other hand, we show that the blocking time distribution becomes exponential as the number of wavelengths increases, regardless of the burst size distribution. Since the burst size distribution is determined by the burst assembly algorithm at the network edges, we conclude that the burst assembly algorithm will have no influence on both burst blocking probability and burst blocking time in future DWDM networks.
Open Access
On the design and performance evaluation of automatic traffic report generation systems with huge data volumes
(Wiley, 2018) Vega, Carlos; Miravalls-Sierra, Eduardo; Julián-Moreno, Guillermo; López de Vergara, Jorge E.; Magaña Lizarrondo, Eduardo; Aracil Rico, Javier; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
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 corrective actions. With the ever-increasing bandwidth of current networks, the design of automated traffic report generation systems is very challenging. In a first step, the huge volumes of collected traffic are transformed into enriched flow records obtained from diverse collectors and dissectors. Then, such flow records, along with time series obtained from the raw traffic, are further processed to produce a usable report. As will be shown, the data volume in flow records turns out to be very large as well and requires careful selection of the Key Performance Indicators (KPIs) to be included in the report. In this regard, we discuss the use of high-level languages versus low-level approaches, in terms of speed and versatility. Furthermore, our design approach is targeted for rapid development in commodity hardware, which is essential to cost-effectively tackle demanding traffic analysis scenarios. Actually, the paper shows feasibility of delivering a large number of KPIs, as will be detailed later, for several TBytes of traffic per day using a commodity hardware architecture and high-level languages.
Open Access
IPmiser: herramienta de medida and análisis de redes de alta velocidad
(1999) Aracil Rico, Javier; Morató Osés, Daniel; Izal Azcárate, Mikel; Automática y Computación; Automatika eta Konputazioa
Las redes de área extensa IP generan en la actualidad un tráfico difícil de predecir y caracterizar. Así, se hace necesario disponer de herramientas que proporcionen monitorización en tiempo real de los enlaces, sin interrupción y con la máxima fiabilidad y precisión de reloj. La herramienta IPmiser consigue este objetivo mediante un hardware dedicado y una estación de trabajo para el proceso de datos, que es además servidor seguro de información de monitorización. En este artículo se presenta la arquitectura de IPmiser, junto con los resultados más destacables de diversas mediciones en el enlace IP sobre ATM de la Universidad Publica de Navarra.