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
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.
Open Access
IP traffic prediction and equivalent bandwidth for DAMA TDMA protocols
(IEEE, 2003) Aracil Rico, Javier; Izal Azcárate, Mikel; Morató Osés, Daniel; Magaña Lizarrondo, Eduardo; Automática y Computación; Automatika eta Konputazioa
The use of IP traffic prediction techniques for DAMA TDMA protocols is investigated in this paper. The predicted traffic distribution is derived when the input traffic shows long-range dependence features. Furthermore, an equivalent bandwidth is calculated, which allows the wireless terminal to request a certain amount of bandwidth (slot duration) in terms of a target traffic loss probability. The numerical results indicate very good traffic prediction capabilities, together with moderate bandwidth loss.
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
Characterizing Internet load as a non-regular multiplex of TCP streams
(IEEE, 2000) Aracil Rico, Javier; Morató Osés, Daniel; Automática y Computación; Automatika eta Konputazioa
A commonly accepted traffic model for a large population of Internet users consists of a multiplex of Poisson-arriving heavy-tailed streams with the same constant rate (M/G//spl infin/). We show that even though such a regular model provides an accurate description of long-range dependence, the marginal distribution variance is underestimated, resulting in erroneous calculation of overflow probability in network simulations. On the other hand, we show that the traffic variability due to the marginal distribution variance can be the limiting factor for performance in the gigabit-speed next-generation Internet, rather than the long-range dependence features present in today's traffic.
Open Access
IPmiser, sistema de monitorización de enlaces ATM a 155Mbps
(1998) Aracil Rico, Javier; Morató Osés, Daniel; Izal Azcárate, Mikel; Solana, Juan Ignacio; Ariste, Teresa; Fillmore, David; Automática y Computación; Automatika eta Konputazioa
Open Access
Analysis of Internet services in IP over ATM networks
(IEEE, 1999) Aracil Rico, Javier; Morató Osés, Daniel; Izal Azcárate, Mikel; Automática y Computación; Automatika eta Konputazioa
This paper presents a trace-driven analysis of IP over ATM services from a user-perceived quality of service standpoint. QoS parameters such as the sustained throughput for transactional services and other ATM layer parameters such as the burstiness (MBS) per connection are derived. On the other hand, a macroscopic analysis that comprises percentage of flows and bytes per service, TCP transaction duration and mean bytes transferred in both ways is also presented. The traffic trace is obtained with a novel measurement equipment that combines a header extraction hardware and a high end UNIX workstation capable of providing a timestamp accuracy in the order of microseconds. The ATM link under analysis concentrates traffic from a large population of 1,500 hosts from Public University of Navarra campus network, that produce 1,700,000 TCP connections approximately in the measurement period of one week. The results obtained from such a wealth of data suggest that QoS is primarily determined by transport protocols and not by ATM bandwidth. The sustained throughput of TCP connections never grows beyond 80 Kbps with 70% probability in the data transfer phase (i. e., in the ESTABLISHED state) and we observe a strong influence of the connection establishment phase in the user-perceived throughput. On the other hand, the burstiness of individual TCP connections is rather small, namely TCP connections do not produce bursts according to the geometric law given by slow start and commonly assumed in previously published studies.
Open Access
The ETOMIC active probing infrastructure: demo proposal
(2006) Csabai, István; Hága, Péter; Simon, Gábor; Stéger, József; Vattay, Gábor; Magaña Lizarrondo, Eduardo; Morató Osés, Daniel; Izal Azcárate, Mikel; Aracil Rico, Javier; Automática y Computación; Automatika eta Konputazioa
ETOMIC (www.etomic.org) is a European Union sponsored effort, that aims at providing a Paneuropean traffic measurement infrastructure. This infrastructure contains 15 PC based active probing nodes equipped with high-precision, sending capable DAG cards and GPS receivers to achieve time synchronization. Such cards are specifically designed to transmit packet trains with strict timing, in the range of nanoseconds. Every kind of active probing techniques can be applied on the nodes, from the quite simple ping application to the complex network tomography methods which are based on the synchronized sending capability of the DAG cards. The measurement nodes are centrally managed via a web platform, where the new arbitrary measurement jobs can be uploaded to and handled. The management system schedules the jobs and does the maintenance tasks. Now, the infrastructure is opened to the networking community. This paper describes the node architectures, the management system, and the proposed conference demonstration.
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 Konputazioa
The 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.
Open Access
Video over OBS Networks
(2008) Espina Antolín, Félix; Morató Osés, Daniel; Izal Azcárate, Mikel; Magaña Lizarrondo, Eduardo; Automática y Computación; Automatika eta Konputazioa