Person: García-Jiménez, Santiago
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García-Jiménez
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Santiago
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Ingeniería Eléctrica, Electrónica y de Comunicación
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ISC. Institute of Smart Cities
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0000-0002-8313-2986
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5549
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Publication Open Access Pamplona-traceroute: topology discovery and alias resolution to build router level Internet maps(IEEE, 2013) García-Jiménez, Santiago; Magaña Lizarrondo, Eduardo; Morató Osés, Daniel; Izal Azcárate, Mikel; Automática y Computación; Automatika eta KonputazioaAn Internet topology map at the router level not only needs to discover IP addresses in Internet paths (traceroute) but also needs to identify IP addresses belonging to the same router (IP aliases). Both processes, discovery and IP alias resolution, have traditionally been independent tasks. In this paper, a new tool called Pamplona-traceroute is proposed to improve upon current results in a state of the art for Internet topology construction at the router level. Indirect probing using TTLscoped UDP packets, usually present in the discovery phases, is reused in IP alias resolution phases, providing high identification rates, especially in access routers.Publication 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 KonputazioaOne 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.Publication 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 IngeniaritzarenTraffic 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.Publication Open Access Internet mapping at IP level(2009) García-Jiménez, Santiago; Magaña Lizarrondo, Eduardo; Automática y Computación; Automatika eta KonputazioaThe final objective of our research is to develop new techniques and ideas to create topology maps at IP level, representing Internet as a graph where nodes were routes. This means closer to reality.Publication Open Access IP addresses distribution in Internet and its application on reduction methods for IP alias resolution(IEEE, 2009) García-Jiménez, Santiago; Magaña Lizarrondo, Eduardo; Izal Azcárate, Mikel; Morató Osés, Daniel; Automática y Computación; Automatika eta KonputazioaDiscovery of Internet topology is an important and open task. It is difficulted by the high number of networks and internetworking equipments, and even by the dynamic of those interconnections. Mapping Internet at router-level needs to identify IP addresses that belong to the same router. This is called IP address alias resolution and classical methods in the state of the art like Ally need to test IP addresses in pairs. This means a very high cost in traffic generated and time consumption, specially with an increasing topology size. Some methods have been proposed to reduce the number of pairs of IP addresses to compare based on the TTL or IP identifier fields from the IP header. However both need extra traffic and they have problems with the probing distribution between several probing nodes. This paper proposes to use the peculiar distribution of IP addresses in Internet Autonomous Systems in order to reduce the number of IP addresses to compare. The difference between pairs of IP addresses is used to know a priori if they are candidates to be alias with certain probability. Performance evaluation has been made using Planetlab and Etomic measurement platforms. The paper justifies the reduction method, obtaining high reduction ratios without injecting extra traffic in the network and with the possibility to distribute the process for alias resolution.Publication Open Access Resolución de alias para el cálculo de topologías(2007) García-Jiménez, Santiago; Magaña Lizarrondo, Eduardo; Izal Azcárate, Mikel; Morató Osés, Daniel; Automática y Computación; Automatika eta KonputazioaThe network topology is a fundamental parameter for managers and researchers. The traditional methodology for discovering the topology of a network is based on the tool traceroute, used from several vantage points in different subnetworks. The result is a set of sink trees where the nodes are the discovered IP addresses from the routers. However, few tools have faced the problem of identifying the nodes in different sink trees as interfaces in the same router. This paper shows a new methodology for this problem of alias resolution. It has been used in the european research network using the ETOMIC platform. It shows that the traditional methodologies are not effective in today’s networking scenario but can be easily improved at least in a factor of 3 in the number of successes.Publication Open Access Computation of traffic time series for large populations of IoT devices(MDPI, 2018) Izal Azcárate, Mikel; Morató Osés, Daniel; Magaña Lizarrondo, Eduardo; García-Jiménez, Santiago; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de ComunicaciónEn este artículo se estudian las tecnicas para clasificar paquetes de tráfico de red en múltiples clases orientadas a la realización de series temporales de tráfico en escenarios de un elevado numero de clases como pueden ser los proveedores de red para dispositivos IoT. Se muestra que usando técnicas basadas en DStries se pueden monitorizar en tiempo real redes con decenas de miles de dispositivos.Publication Open Access ETOMIC advanced network monitoring system for future Internet experimentation(Springer-Verlag Berlin Heidelberg, 2010) Csabai, István; Fekete, Attila; Hága, Péter; Hullár, Béla; Kurucz, Gábor; Laki, Sándor; Mátray, Péter; Stéger, József; Vattay, Gábor; Espina Antolín, Félix; García-Jiménez, Santiago; Izal Azcárate, Mikel; Magaña Lizarrondo, Eduardo; Morató Osés, Daniel; Aracil Rico, Javier; Gómez, Francisco; González, Iván; López Buedo, Sergio; Moreno, Víctor; Ramos, Javier; Automática y Computación; Automatika eta KonputazioaETOMIC is a network traffic measurement platform with high precision GPS-synchronized monitoring nodes. The infrastructure is publicly available to the network research community, supporting advanced experimental techniques by providing high precision hardware equipments and a Central Management System. Researchers can deploy their own active measurement codes to perform experiments on the public Internet. Recently, the functionalities of the original system were significantly extended and new generation measurement nodes were deployed. The system now also includes well structured data repositories to archive and share raw and evaluated data. These features make ETOMIC as one of the experimental facilities that support the design, development and validation of novel experimental techniques for the future Internet. In this paper we focus on the improved capabilities of the management system, the recent extensions of the node architecture and the accompanying database solutions.Publication Open Access TBDClust: time-based density clustering to enable free browsing of sites in pay-per-use mobile Internet providers(Elsevier, 2017) Torres García, Luis Miguel; Magaña Lizarrondo, Eduardo; Morató Osés, Daniel; García-Jiménez, Santiago; Izal Azcárate, Mikel; Automatika eta Konputazioa; Institute of Smart Cities - ISC; Automática y ComputaciónThe World Wide Web has evolved rapidly, incorporating new content types and becoming more dynamic. The contents from a website can be distributed between several servers, and as a consequence, web traffic has become increasingly complex. From a network traffic perspective, it can be difficult to ascertain which websites are being visited by a user, let alone which part of the user's traffic each website is responsible for. In this paper we present a method for identifying the TCP connections involved in the same full webpage download without the need of deep packet inspection. This identification is needed for example to enable free browsing of specific websites in a pay per use mobile Internet access. It could be not only for third party promoted websites but also portals to gubernamental or medical emergency websites. The proposal is based on a modification of the DBSCAN clustering algorithm to work online and over one-dimensional sorted data. In order to validate our results we use both real traffic and packet captures from a controlled environment. The proposal achieves excellent results in consistency (99%) and completeness (92%), meaning that its error margin identifying the webpage downloads is minimal.Publication Open Access Improving efficiency of IP alias resolution based on offsets between IP addresses(IEEE, 2009) García-Jiménez, Santiago; Magaña Lizarrondo, Eduardo; Morató Osés, Daniel; Izal Azcárate, Mikel; Automática y Computación; Automatika eta KonputazioaIn order to get a router-level topology in Internet, IP address alias resolution techniques allow to identify IP addresses that belong to the same router. There are several proposals to make this identification, some based on active measurements and others based on inference studies. The former provides more accuracy and completeness, however efficiency is very low because of the high number of probes needed. These methods probe IP addresses in pairs. With thousands or even more IP addresses to check for aliases, the number of tests gets too high. In order to reduce the number of probes, we propose to select the pairs of IP addresses to test for aliasing using information available a priori. This selection will be based on the offset (numerical distance) between the IP addresses to test. We will show that we can improve efficiency of active alias identification with almost no loss on completeness and without generating probing traffic. The technique is also adaptable to a distributed measurement scenario.