Open Access
Ingress traffic classification versus aggregation in video over OBS networks
(2010) Izal Azcárate, Mikel; Espina Antolín, Félix; Morató Osés, Daniel; Magaña Lizarrondo, Eduardo; Automática y Computación; Automatika eta Konputazioa
Optical Burst Switched (OBS) networks may become a backbone technology for video-on-demand providers. This work addresses the problem of dimensioning the access link of an ingress node to the optical core network in a video over OBS scenario. A video-ondemand provider using an OBS transport network will have to deliver traffic to a set of egress destinations. A large part of this traffic would be composed of video streaming traffic. However, in a real network there would be also a fraction of non video traffic related to non video services. This work studies the decision whether it is better to gather all traffic to the same destination in a joint burst assembler or separate video and general data traffic on different burs assemblers. The later may increase burst blocking probability but also allow for better tuning of OBS parameters that help improve video reception quality. Result show that this tuning of parameters is not enough to compensate the drop probability increase and thus it is better to aggregate video and general data traffic.
Open Access
A proposal of burst cloning for video quality improvement in optical burst switching networks
(2013) Espina Antolín, Félix; Morató Osés, Daniel; Izal Azcárate, Mikel; Magaña Lizarrondo, Eduardo; Automática y Computación; Automatika eta Konputazioa
Open Access
Ransomware early detection by the analysis of file sharing traffic
(Elsevier, 2018) Morató Osés, Daniel; Berrueta Irigoyen, Eduardo; Magaña Lizarrondo, Eduardo; Izal Azcárate, Mikel; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
Crypto ransomware is a type of malware that locks access to user files by encrypting them and demands a ransom in order to obtain the decryption key. This type of malware has become a serious threat for most enterprises. In those cases where the infected computer has access to documents in network shared volumes, a single host can lock access to documents across several departments in the company. We propose an algorithm that can detect ransomware action and prevent further activity over shared documents. The algorithm is based on the analysis of passively monitored traffic by a network probe. 19 different ransomware families were used for testing the algorithm in action. The results show that it can detect ransomware activity in less than 20 s, before more than 10 files are lost. Recovery of even those files was also possible because their content was stored in the traffic monitored by the network probe. Several days of traffic from real corporate networks were used to validate a low rate of false alarms. This paper offers also analytical models for the probability of early detection and the probability of false alarms for an arbitrarily large population of users.
Open Access
A survey on detection techniques for cryptographic ransomware
(IEEE, 2019) Berrueta Irigoyen, Eduardo; Morató Osés, Daniel; Magaña Lizarrondo, Eduardo; Izal Azcárate, Mikel; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
Crypto-ransomware is a type of malware that encrypts user files, deletes the original data, and asks for a ransom to recover the hijacked documents. It is a cyber threat that targets both companies and residential users, and has spread in recent years because of its lucrative results. Several articles have presented classifications of ransomware families and their typical behaviour. These insights have stimulated the creation of detection techniques for antivirus and firewall software. However, because the ransomware scene evolves quickly and aggressively, these studies quickly become outdated. In this study, we surveyed the detection techniques that the research community has developed in recent years. We compared the different approaches and classified the algorithms based on the input data they obtain from ransomware actions, and the decision procedures they use to reach a classification decision between benign or malign applications. This is a detailed survey that focuses on detection algorithms, compared to most previous studies that offer a survey of ransomware families or isolated proposals of detection algorithms. We also compared the results of these proposals.
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 Konputazioa
An 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.
Open Access
A popularity-aware method for discovering server IP addresses related to websites
(IEEE, 2013) Torres García, Luis Miguel; Magaña Lizarrondo, Eduardo; Izal Azcárate, Mikel; Morató Osés, Daniel; Automática y Computación; Automatika eta Konputazioa
The complexity of web traffic has grown in the past years as websites evolve and new services are provided over the HTTP protocol. When accessing a website, multiple connections to different servers are opened and it is usually difficult to distinguish which servers are related to which sites. However, this information is useful from the perspective of security and accounting and can also help to label web traffic and use it as ground truth for traffic classification systems. In this paper we present a method to discover server IP addresses related to specific websites in a traffic trace. Our method uses NetFlow-type records which makes it scalable and impervious to encryption of packet payloads. It is, moreover, popularity-aware in the sense that it takes into consideration the differences in the number of accesses to each site in order to provide a better identification of servers. The method can be used to gather data from a group of interesting websites or, by applying it to a representative set of websites, it can label a sizeable number of connections in a packet trace.
Open Access
Performance evaluation of client-based traffic sniffing for very large populations
(Elsevier, 2019-11-09) Roquero, Paula; Magaña Lizarrondo, Eduardo; Leira, Rafael; Aracil Rico, Javier; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza
Current Internet users are demanding an increased mobility and service ubiquity, which, in turns, requires that Internet services are provided from different datacenters in the cloud. Traffic monitoring in such a mobile scenario, for security and QoS monitoring purposes, is rather challenging, as the sniffing points may be fully distributed in the operator's network. To complicate matters, out-going traffic may leave the network through a given PoP and return through a different one. As a result, traffic monitoring at the edges, at the very client terminal or domestic router, becomes a sensible alternative. However, such a measurement scheme implies that millions of tiny monitoring probes are contin- uously producing flow r ecords, which builds up a significant load fo r the monitoring data collector and for the network itself, aside from the induced load to the client terminal or router. In this paper, we study whether such large scale deployment of microsniffers is feasible in terms of the resulting load, namely deployment of lightweight network probes that perform passive measurements at the client terminal. We further propose data summarization schemes to reduce load with minimum information loss. Our findings show that deployment of a large populations of microsniffers is feasible, provided that adequate data thinning techniques are provided, as we propose in this paper.
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
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 Comunicación
En 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.
Open Access
On the nature of unused TCP connections in web traffic
(2015) Torres García, Luis Miguel; Magaña Lizarrondo, Eduardo; Izal Azcárate, Mikel; Morató Osés, Daniel; Automática y Computación; Automatika eta Konputazioa
The popularity of the web and the requirements introduced by current web content have pushed for the development of new techniques that meet these challenges and improve the experience of the users. In particular, during the last years, web browsers have taken aggressive measures in order to reduce webpage download times. These measures have had a noteworthy effect on the profile of web traffic. One of the most striking consequences is that nowadays, more than 20% of the TCP connections opened by a browser are left unused. In this paper we describe these connections, explain why they happen and use them as a simple way of identifying the traffic of different web browsers.