Medidas de capacidad en entornos P2P usando técnicas de dispersión de paquetes

En el presente artículo se recopilan y analizan los trabajos realizados en el seno de nuestro grupo de investigación en el campo de la medición de capacidades en redes peer-to-peer utilizado técnicas de dispersión de paquetes. Así, se analizará la importancia que este tipo de mediciones tiene asociadas y se expondrán las técnicas y fundamentos necesarios para llevarlas a cabo. En este punto se detallará la herramienta de medición implementada así como la técnica de medición desarrollada. Igualmente, se expondrán los resultados obtenidos y se analizará la bondad de nuestra herramienta de medición mediante el análisis de los diferentes escenarios posibles en una implementación real de una red peer-to-peer típica hecha a tal efecto. Se finalizará exponiendo las líneas futuras de investigación que se abren tras la realización de estos trabajos.Plan Nacional I+D+i "Characterization, evaluation, planning and improvement of key technologies fot the future Internet: knowledge and transfer (CALM)

A new proposal for assuring services in internet

In this paper we present a new mechanism to provide an assured service in terms of target rate and fair excess bandwidth, like the Internet Assured Service. Research in Internet Assured Service faced up both questions in separate ways proposing different traffic conditioners to work with the RIO buffer management, and proposing different modifications to this buffer management, among others. In this work, we suggest using a buffer management scheme different from RIO that also treats in-of-profile and out-of-profile packets differently but avoiding interference between them. This scheme is used together with the Counters Based traffic conditioner because of its high accuracy in guaranteeing target rates. We evaluate and compare by simulation the performance of our proposal using TCP RENO sources. One important issue to be considered is that the proposal is a feasible alternative to the standard architecture for Differentiated Services in Internet.This work was supported by the Spanish Research Council under grant TIC2000-1734- C03-03

Análisis de las prestaciones del acondicionador de tráfico CBM en un dominio DiffServ

The Counters-Based Modified (CBM) traffic conditioner was introduced in a previous work as a feasible option to implement the Assured Forwarding (AF) service in DiffServ. In this paper we present an end-to-end performance analysis of TCP Reno sources that employ the CBM in a DiffServ domain. We present simulation results in a three-RIO-node topology under miscellaneous characteristics: different contract rates, heterogeneous RTT, co-existance of best-effort and AF sources, and eficience of CBM when some network node does not implement service differentiation. As shown in simulation results, it is possible to guarantee an AF service that ensures contracted target rates and performs a fair share of the excess bandwidth.Este trabajo se enmarca dentro del proyecto CICYT FAR-IP (TIC2000-1734-C03-03)

Performance evaluation of profiler mechanisms for the internet assured service

As Internet is rapidly growing and receiving traffic from multimedia applications that are sensitive to available bandwidth and delay experienced in the network, there is a strong need for quality of service (QoS) support. The Integrated and Differentiated Service models are two approaches for adding QoS to Internet. The Assured Service is an end-to-end service based on the Differentiated Service architecture. In this paper, we study and compare the performance of three profiler mechanisms to provide the guaranties of an Internet Assured Service. Two of them, TSW and Leaky Bucket are the most commonly used, and the third is a new Counter Based profiler, which is proposed in this paper. The study is done by simulation employing TCP RENO sources.This work was partly supported by the Spanish Research Council under grant TIC2000-1734-C03-03

Counters-based modified traffic conditioner

Traffic conditioners play a key role in implementing the Assured Service in the framework of the DiffServ approach. Many research papers have focused on finding the best traffic conditioner able to assure contracted target rates and to fairly distribute the excess bandwidth among competing sources. Nevertheless, none of the proposals presented so far accomplishes simultaneously both features. We propose a traffic conditioner for the Internet Assured Service called Counters-Based Modified (CBM) that strictly guarantees target rates and performs a fair share of the excess bandwidth among TCP Reno sources. The ability of strictly providing the inbound bandwidth is inherited from its predecessor the Counters-Based algorithm, and the fairness in the outbound bandwidth distribution is met by probabilistically dropping OUT packets in the traffic conditioner. To determine the dropping probability of an OUT packet, the amount of excess bandwidth and the average RTT of all connections in the traffic conditioner have to be known. Although this fact implies using some sort of signaling, it results more feasible than other proposed intelligent traffic conditioners. The CBM traffic conditioner is evaluated under different conditions by simulation using TCP Reno sources. Simulation results presented in this paper lead us to suggest it as a feasible election for the traffic conditioner device implementation in DiffServ.This work was supported by the Spanish Research Council under grant FAR-IP TIC2000-1734-C03-03

Desarrollo de servicios y sistemas de comunicación sobre redes overlay peer-to-peer

Las redes overlay aparecen con el objetivo de hacer frente a diferentes retos que han aparecido en Internet, tales como la necesidad de proporcionar servicios heterogéneos o la de controlar una red enorme en términos de complejidad y tamaño. Durante los últimos años el Grupo de Ingeniería Telemática de la UPCT ha trabajado en el estudio de los retos de un tipo específico de redes overlay, concretamente las redes P2P. Durante este tiempo se han realizado diferentes diseños con el objetivo de automatizar la gestión de este tipo de redes, proporcionar anonimato y facilitar la transmisión de contenidos multimedia en aplicaciones de video bajo demanda (VoD, Video-on-Demand).Plan I+D+i "Contribución a los nuevos paradigmas y tecnologías de red para las comunicaciones del mañana (CON-PARTE-1)" TEC2007-67966-C03-01/TC

Internet measurements and data study over the regional network Ciez@net

In this paper we present the most signifcant results studying the Internet network traffic measurements obtained in Ciez@net. Ciez@net is a citizen subnet located in the village of Cieza that belongs to the regional network of the Autonomous Community of Murcia in Spain. This subnet is one of the firsts pilot experiences of a Digital City in Europe and the first in the Region of Murcia. The goal is the seamless introduction of the Information Society in a medium-size population. Access to advanced electronic information services is stimulated or subsidized for an effective penetration. These measurements will allow a qualitative and quantitative knowledge of the network trafJic in order to achieve a most effective network resource provisioning and Internet trafic forecasting in a real scenario. A suitable dimensioning of the network as well as an adequate provisioning of Quality of Service to users may depend partially on these results. Measurements were taken from a Frame Relay link connecting Ciez@net’s users to Internet through the main node located in Murcia city. We used a promiscuous network analyzer that avoids intelfering in the network trafic. We report results of traffic load, network pelformance, percentage composition of trafJic by protocol and type of application, and IP packet size distribution in both, up and down communications streams.This work was partly supported by the Spanish Research Council under grant TIC2000- 1734- CO3-03 and by the Fundaci6n Integra under project 01 24

TAT: traffic analysis tool for the statistical study of IP networks

In this paper, we present a new software package, TAT, that allows the statistical study of the IP traflc transmitted trough an Internet node. This tool has been successfully tested under a work cam'ed out in a subnet of the regional network of Murcia (Spain) called Ciez@net. Cieza is a village of 30,000 people where the pilot network Ciez@net intends to bring these people the opportunity to use the new emerging Internet applications in their daily life. The goal of the traffic analysis tool developed in this project has been to analyse the IP trafic transmitted in the regional network in order to figure out if the economic effort done during the network deployment and operation was worth enough regarding the use that people do of the network services and infrastructure. The success of this software tool lies on its flexibility, easy handling and intelface independence.This work was partly supported by the Spanish Research Council under grant TIC2000-1734- C03-03 and by the Fundación Integra under project 0124

Análisis y caracterización del tráfico IP en la red regional Ciez@net

In this paper, we present the most significant results studying the Internet network traffic measurements obtained in Ciez@net. Ciez@net is a citizen subnet located in the village of Cieza that belongs to the regional network of the Autonomous Community of Murcia in Spain. This subnet is one of the firsts pilot experiences of a Digital City in Europe and the first in the Region of Murcia. The goal is the seamless introduction of the Information Society in a medium-size population. Access to advanced electronic information services is stimulated or subsidized for an effective penetration. These measurements will allow a qualitative and quantitative knowledge of the network traffic in order to achieve a most effective network resource provisioning and Internet traffic forecasting in a real scenario. A suitable dimensioning of the network as well as an adequate provisioning of Quality of Service to users may depend partially on these results. Measurements were taken from a Frame Relay link connecting Ciez@net users to Internet through the main node located in Murcia city. We used a promiscuous network analyzer that avoids interfering with network traffic. We report results of traffic load, network performance, percentage composition of traffic by protocol and type of application, and IP packet size distribution in both up and down communications streams.Este trabajo ha sido parcialmente financiado por el Ministerio de Educación y Ciencia (TIC2000- 1734-C03-03) y por la Fundación Integra con el proyecto 0124

An INT‐based packet loss monitoring system for data center networks implementing Fine‐Grained Multi‐Path routing

In-band network telemetry (INT) is a newer network measurement technology that uses normal data packets to collect network information hop-by-hop with low overhead. Since incomplete telemetry data seriously degrades the performance of upper-layer network telemetry applications, it is necessary to consider the own INT packet loss. In response, LossSight, a powerful packet loss monitoring system for INT has been designed, implemented, and made available as open-source. This letter extends the previous work by proposing, implementing, and evaluating LB-LossSight, an improved version compatible with packet-level load-balancing techniques, which are currently used in modern Data Center Networks. Experimental results in a Clos network, one of the most commonly used topologies in today's data centers, confirm the high detection and localization accuracy of the implemented solution.Spanish State Research Agency (AEI), under project grant AriSe2: FINe, (Ref.PID2020-116329GB-C22 founded by MCIN/AEI/10.13039/501100011033) and the project (Natural Science Foundation of Shandong Province under Grant No. ZR2020LZH010)