Desempeño de tráfico tipo streaming en una red de datos simulada

Este artículo presenta un estudio e investigación realizados, en vinculación al área de redes de datos, en particular referido al desempeño en la transferencia de información. Describe el proceso sobre cómo es dicha transferencia sobre una red simulada por software. Realiza una comparación de los desempeños alcanzados para distintas velocidades de transferencia de datos tipo streaming. Se analizan los resultados, en base a una serie de parámetros considerados como son el throughput, el delay (retardo), el packet loss (pérdida de paquetes) y el jitter (variación del retardo). Se concluye con una reflexión sobre que parámetros afectan en mayor o menor medida las transferencias realizadas.Presentado en el VI Workshop Arquitectura, Redes y Sistemas Operativos (WARSO)Red de Universidades con Carreras en Informática (RedUNCI

Light-weight overlay path selection in a peer-to-peer environment

Large-scale peer-to-peer systems span a wide range of Internet locations. Such diversity can be leveraged to build overlay “detours” to circumvent periods of poor performance on the default path. However, identifying which peers are “good” relay choices in support of such detours is challenging, if one is to avoid incurring an overhead that grows with the size of the peer-to-peer system. This paper proposes and investigates the Earliest Branching Rule (EBR) to perform such a selection. EBR builds on the Earliest Diverging Rule (EDR) that selects relay nodes whose AS path diverges from the default path at the earliest possible point, but calls for monitoring a much smaller number of paths. As a result, it has a much lower overhead. The paper explores the performance and overhead of EBR, and compares them to that of EDR. The results demonstrate that EBR succeeds in selecting good relay nodes with minimum control overhead. Hence, providing a practical solution for dynamically building good overlays in large peer-to-peer systems

Light-Weight Overlay Path Selection in a Peer-to-Peer Environment

Large-scale peer-to-peer systems span a wide range of Internet locations. Such diversity can be leveraged to build overlay “detours” to circumvent periods of poor performance on the default path. However, identifying which peers are “good” relay choices in support of such detours is challenging, if one is to avoid incurring an overhead that grows with the size of the peer-to-peer system. This paper proposes and investigates the Earliest Branching Rule (EBR) to perform such a selection. EBR builds on the Earliest Diverging Rule (EDR) that selects relay nodes whose AS path diverges from the default path at the earliest possible point, but calls for monitoring a much smaller number of paths. As a result, it has a much lower overhead. The paper explores the performance and overhead of EBR, and compares them to that of EDR. The results demonstrate that EBR succeeds in selecting good relay nodes with minimum control overhead. Hence, providing a practical solution for dynamically building good overlays in large peer-to-peer systems

Light-Weight Overlay Path Selection in a Peer-to-Peer Environment

Abstract — Large-scale peer-to-peer systems span a wide range of Internet locations. Such diversity can be leveraged to build overlay “detours ” to circumvent periods of poor performance on the default path. However, identifying which peers are “good” relay choices in support of such detours is challenging, if one is to avoid incurring an overhead that grows with the size of the peerto-peer system. This paper proposes and investigates the Earliest Branching Rule (EBR) to perform such a selection. EBR builds on the Earliest Diverging Rule (EDR) that selects relay nodes whose AS path diverges from the default path at the earliest possible point, but calls for monitoring a much smaller number of paths. As a result, it has a much lower overhead. The paper explores the performance and overhead of EBR, and compares them to that of EDR. The results demonstrate that EBR succeeds in selecting good relay nodes with minimum control overhead. Hence, providing a practical solution for dynamically building good overlays in large peer-to-peer systems. I

A system for improving the quality of real-time services on the internet

Real-time Internet services are becoming more popular every day, and Voice over Internet Protocol (VOIP) is arguably the most popular of these, despite the quality and reliability problems that are so characteristic of VOIP. This thesis proposes to apply a routing technique called Fully Redundant Dispersity Routing to VOIP and shows how this mitigates these problems to deliver a premium service that is more equal to traditional telephony than VOIP is currently.Fully Redundant Dispersity Routing uses the path diversity readily available in the Internet to route complete copies of the data to be communicated over multiple paths. This allows the effect of a failure on a path to be reduced, and possibly even masked completely, by the other paths. Significantly, rather than expecting changes of the Internet that will improve real-time service quality, this approach simply changes the manner in which real-time services use the Internet, leaving the Internet itself to stay the way it is.First, real VOIP traffic in a commercial call centre is measured (1) to establish a baseline of current quality characteristics against which the effects of Fully Redundant Dispersity Routing may be measured, and (2) as a source of realistic path characteristics. Simulations of various Fully Redundant Dispersity Routing systems that adopt the measured VOIP traffic characteristics then (1) show how this routing technique mitigates quality and reliability problems, and (2) quantify the quality deliverable with the VOIP traffic characteristics measured. For example, quantifying quality as a Mean Opinion Score (MOS) estimated from the measurements with the International Telecommunication Union’s E-model, slightly more than 1 in every 23 of the VOIP telephone calls measured in the call centre is likely to be perceived to be of a quality with which humans would be less than very satisfied. Simulations carried out for this thesis show that using just two paths adopting the same measurements, Fully Redundant Dispersity Routing may increase quality to reduce that proportion to slightly less than 1 in every 10 000 VOIP telephone calls