Open Access
TNS research in progress
(Universidad Politécnica de Cartagena, Servicio de Documentación, 2012) Izal Azcárate, Mikel; Prieto Suárez, Iria; Espina Antolín, Félix; Morató Osés, Daniel; Magaña Lizarrondo, Eduardo; Automática y Computación; Automatika eta Konputazioa; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
This paper summarizes latest works of Telematic, Networks and Services research group (TNS) of Public University of Navarra in the topics of FIERRO thematic network. Last two papers sent to major conferences are addressed First work shows how self-similar traffic can be generated using Perlin Noise, an algorithm commonly used to generate 2D/3D noise for natural looking graphics. 1-dimension Perlin Noise can be interpreted as network traffic and used to generate long range dependent traffic for network simulation. The algorithm is compared to more classical approach Random Midpoint Displacement showing at traffic generated is similar but can be generated continuously with no fixed block size. Second work presents two novel cloning schemes for video delivery in OBS networks that dramatically improve user perceived content quality. These schemes take into account the special characteristics of compressed video traffic. Analytical and simulation results show up to 40% QoE improvement without a substantial increase in the overall network traffic and without increasing the number of bursts in the network. The results show the strong dependency of this novel cloning scheme on the video traffic structure due to the coding mechanisms.
Open Access
Midiendo retardos y pérdidas en las redes móviles de alta velocidad
(2015) Prieto Suárez, Iria; Izal Azcárate, Mikel; Magaña Lizarrondo, Eduardo; Morató Osés, Daniel; Automática y Computación; Automatika eta Konputazioa
Mobile networks are constantly evolving, but still, due to their nature, it is not trivial to analayse how they face up different kinds of traffic. On the Internet a wide range of services can be found. Usually the majority send large packets, i.e Web services, but others, like VoIP, send small packets. The question is how the mobile networks manage all this traffic. In this work experiments to measure losses and times of sending different packet size bursts are described. Also, preliminary results for experiments with a real network mobile client, are analaysed showing that the performance of the network is different depending on the size of packet.
Open Access
Techniques for better alias resolution in Internet topology discovery
(IEEE, 2009) García-Jiménez, Santiago; Magaña Lizarrondo, Eduardo; Morató Osés, Daniel; Izal Azcárate, Mikel; Automática y Computación; Automatika eta Konputazioa
One of the challenging problems related with network topology discovery in Internet is the process of IP address alias identification. Topology information is usually obtained from a set of traceroutes that provide IP addresses of routers in the path from a source to a destination. If these traceroutes are repeated between several source/destination pairs we can get a sampling of all IP addresses for crossed routers. In order to generate the topology graph in which each router is a node, it is needed to identify all IP addresses that belong to the same router. In this work we propose improvements over existing methods to obtain alias identification related mainly with the types and options in probing packets.
Open Access
Instrumentation for measuring users' goodputs in dense Wi-Fi deployments and capacity-planning rules
(Springer Nature, 2020-01-11) García-Dorado, José Luis; Ramos, Javier; Gómez-Arribas, Francisco J.; Magaña Lizarrondo, Eduardo; Aracil Rico, Javier; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza
Before a dense Wi-Fi network is deployed, Wi-Fi providers must be careful with the performance promises they made in their way to win a bidding process. After such deployment takes place, Wi-Fi-network owners-such as public institutions-must verify that the QoS agreements are being fulfilled. We have merged both needs into a low-cost measurement system, a report of measurements at diverse scenarios and a performance prediction tool. The measurement system allows measuring the actual goodput that a set of users are receiving, and it has been used in a number of schools on a national scale. From this experience, we report measurements for different scenarios and diverse factors-which may result of interest to practitioners by themselves. Finally, we translate all the learned lessons to a freely-available capacity-planning tool for forecasting performance given a set of input parameters such as frequency, signal strength and number of users-and so, useful for estimating the cost of future deployments.
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
Router scheduling configuration based on the maximization of benefit and carried best effort traffic
(Kluwer Academic Publishers, 2003) Magaña Lizarrondo, Eduardo; Morató Osés, Daniel; Varaiya, Pravin; Automática y Computación; Automatika eta Konputazioa
This paper shows a configuration scheme for networks with WFQ schedulers. It guarantees maximum revenue for the service provider in the worst case of network congestion. We focus on best effort traffic and select those flows that maximize the benefit while keeping the network utilization high. We show that optimum network configuration is feasible based only on knowledge of the topology. Its dependence on the pricing scheme can be reduced and even eliminated. We offer a formulation that reaches a tradeoff between network utilization, fairness, and user satisfaction.
Open Access
Arquitectura de publicación automatizada de contenidos educativos supervisados en Internet
(1999) Arin Irastorza, María Asunción; Magaña Lizarrondo, Eduardo; Astrain Escola, José Javier; Villadangos Alonso, Jesús; González de Mendívil Moreno, José Ramón; Automática y Computación; Automatika eta Konputazioa
This paper presents an automated publishing architecture of educational and supervised contents over the Internet. The system makes easier the job of publishing educational courses over the network using specific tools that automates the access control (CGI -- Common Gateway Interface), encrypts the information that goes through the net for not being accessed by strangers (SSL – Secure Sockets Layer), gives an statistical control of the usage of the system, and tutors the course. This project is multiplatform, i.e. all the components that integrate the system are available for any operating system (Windows 9X, Solaris, Linux,...) and it is based on the Web.
Open Access
NATRA: Network ACK-Based Traffic Reduction Algorithm
(IEEE, 2020) García-Jiménez, Santiago; Magaña Lizarrondo, Eduardo; Aracil Rico, Javier; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
Traffic monitoring involves packet capturing and processing at a very high rate of packets per second. Typically, flow records are generated from the packet traffic, such as TCP flow records that feature the number of bytes and packets in each direction, flow duration, number of different ports, and other metrics. Delivering such flow records, about network traffic flowing at tens of Gbps is rather challenging in terms of processing power. To address this problem, traffic thinning can be applied to reduce the input load, by swiftly discarding useless packets at the sniffer NIC or driver level, which effectively reduces the load on software layers that handle traffic processing. This work proposes an algorithm that drops empty ACK packets from TCP traffic, thus achieving a significant reduction in the packets per second that must be handled by each traffic module. The tests discussed below show that the algorithm achieves a 25% decrease in the packets per second rate with minimal information loss.
Open Access
Traffic generator using Perlin Noise
(IEEE, 2012) Prieto Suárez, Iria; Izal Azcárate, Mikel; Morató Osés, Daniel; Magaña Lizarrondo, Eduardo; Automática y Computación; Automatika eta Konputazioa; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Study of high speed networks such as optical next generation burst or packet switched networks require large amounts of synthetic traffic to feed simulators. Methods to generate self-similar long range dependent traffic already exist but they usually work by generating large blocks of traffic of fixed time duration. This limits simulated time or require very high amount of data to be stored before simulation. On this work it is shown how self-similar traffic can be generated using Perlin Noise, an algorithm commonly used to generate 2D/3D noise for natural looking graphics. 1-dimension Perlin Noise can be interpreted as network traffic and used to generate long range dependent traffic for network simulation. The algorithm is compared to more classical approach Random Midpoint Displacement showing at traffic generated is similar but can be generated continuously with no fixed block size.
Open Access
Internet technologies course with combined professor and on-line contents methodology
(IEEE, 2003) Magaña Lizarrondo, Eduardo; Morató Osés, Daniel; Automática y Computación; Automatika eta Konputazioa
In this paper we present the experience and results in the teaching of a course titled “Internet Technologies”. This course, offered in Public University of Navarra (Spain), uses a special methodology that combines in-classroom lectures in front of computers with on-line contents. The students work on the on-line course lesson at the same time that the professor is available in the classroom to help the students during the hours assigned to the course. The tool used to manage the on-line contents, tests, exercises and grades, was designed specially for this course. It incorporates a student profile classification based on the time used to solve the tests.