József Stéger

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The NOVI Information Model (IM) and the corresponding data models are the glue between the software components in the NOVI Service Layer. The IM enables the communication among the various components of the NOVI Architecture and supports the various functionalities it offers. The NOVI IM consists of three main ontologies: resource, monitoring and policy(More)
The European Traffic Observatory is a European Union VI Framework Program sponsored effort, within the Integrated Project EVERGROW, that aims at providing a paneuropean traffic measurement infrastructure with high-precision, GPS-synchronized monitoring nodes. This paper describes the system and node architectures, together with the management system. On the(More)
Despite their relatively low sampling factor, the freely available, randomly sampled status streams of Twitter are very useful sources of geographically embedded social network data. To statistically analyze the information Twitter provides via these streams, we have collected a year’s worth of data and built a multi-terabyte relational database from it.(More)
Distributed network measurements are essential to characterize the structure, dynamics and operational state of the Internet. Although in the last decades several such systems have been created, the easy access of these infrastructures and the orchestration of complex measurements are not solved. We propose a system architecture that combines the(More)
Online sharing of scientific information has accelerated the research activity in various domains of science. This fact inspires us to initiate a new kind of approach in the field of network research and review some projects pointing towards this direction. Building on the experiences of similar efforts in other domains of sciences we are building a(More)
Online sharing of scientific information has accelerated the research activity in various different domains of science. This fact inspires us to initiate this kind of approach in the field of network research and review some projects pointing towards this direction. Using the experiences of similar efforts in other domains of sciences we are building a(More)
This paper presents operational experience of large-scale unicast network tomography, that samples a part of the European Internet. In the paper we describe in detail the ETOMIC measurement platform that was used to conduct the experiments, and its potential in future scaled-up measurements. The main results of the paper are maps showing various spatial and(More)
ETOMIC 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(More)
Abstract In this paper we show how to go beyond the study of the topological properties of the Internet, by measuring its dynamical state using special active probing techniques and the methods of network tomography. We demonstrate this approach by measuring the key state parameters of Internet paths, the characteristics of queueing delay, in a part of the(More)
Monitoring network state can be crucial in Future Internet infrastructures. Passive monitoring of all the routers is expensive and prohibitive. Storing, accessing and sharing the data is a technological challenge among networks with conflicting economic interests. Active monitoring methods can be attractive alternatives as they are free from most of these(More)