Overhead in available bandwidth estimation tools: Evaluation and analysis

Current Available Bandwidth Estimation Tools (ABET) insert into the network probing packets to perform a single estimation. The utilization of these packets makes ABET intrusive and prone to errors since they consume part of the available bandwidth they are measuring. This paper presents a comparative of Overhead Estimation Tools (OET) analysis of representative ABET: Abing, Diettopp, Pathload, PathChirp, Traceband, IGI, PTR, Assolo, and Wbest. By using Internet traffic, the study shows that the insertion of probing packets is a factor that affects two metrics associated to the estimation. First, it is shown that the accuracy is affected proportionally to the amount of probing traffic. Secondly, the Estimation Time (ET) is increased in high congested end-to-end links when auto-induced congestion tools are use

Overhead in Available Bandwidth Estimation Tools: Evaluation and Analysis

The current Available Bandwidth Estimation Tools (ABET's) to perform an estimation, using probes packets are inserted into the network. The utilization These packages, makes ABET's are intrusive and consumes part of which is measuring bandwidth to noise known as "Overhead Estimation Tools" (OET); it’s can produce negative effects on measurements performed by the ABET. This paper presents a complete and comparative analysis of behavior of Available Bandwidth (av_bw), of the ABET's most representative, as well as: Abing, Diettopp, Pathload, PathChirp, Traceband, IGI, PTR, Assolo and Wbest. The study with real Internet traffic, shows the percentage of test that is a factor packets affecting two main aspects of the estimation. The first, the accuracy, and increased indicating that EOT is directly proportional to the percentage of RE, reaching up to 70% in the tool evaluated with most of 30% of Cross-Traffic (CT). And second, the techniques used to send probes packets highly influences the Estimation Time (ET), where some tools that use slops spend up to 240s to converge when there is 60% CT in the network, ensuring that the estimate this technique av_bw highly congested channel, OET as much is used, resulting in inaccuracies in measurement

Timestamp scheme in the reception of test packets through Netfpga for the estimation of available bandwidth in Traceband

Los servicios y aplicaciones que se ofrecen actualmente sobre internet como video bajo demanda, requieren estimación de parámetros que determinen la calidad de una conexión como el ancho de banda disponible. Para la estimación del ancho de banda disponible (ABW) se han desarrollado herramientas de software como Pathload, Spruce y Traceband. Estas herramientas presentan limitaciones en la precisión de la estimación debido a los retardos que sufren los paquetes en los procesos inherentes del sistema operativo. La herramienta requiere precisión en la captura del tiempo de llegada de los paquetes y esto se logra realizando el timestamp a nivel físico. Para ello se utiliza la NetFPGA dado que permite modificar el comportamiento como tarjeta de red adicionando módulos de acuerdo a las necesidades del proyecto. En el diseño del esquema de marcación de los tiempos de llegada de los paquetes de prueba se utiliza la herramienta Traceband, esta se encarga del envío y cálculo del ABW y la NetFPGA se encarga de realizar la marca de tiempo de llegada de los paquetes en la recepción en hardware y basados en este valor se realiza la estimación del ABW. Se diseñaron los módulos Timestamp e Identificación en la NetFPGA, y los cambios requeridos en Traceband para comunicarse con la NetFPGA.The services and applications that are currently offered over the Internet as video on demand, require estimation of parameters that determine the quality of a connection such as the available bandwidth. To estimate the available bandwidth (ABW), software tools such as Pathload, Spruce and Traceband have been developed. These tools present limitations in the precision of the estimation due to the delays suffered by the packets in the inherent processes of the operating system. The tool requires precision in capturing the arrival time of the packets and this is achieved by performing the timestamp at the physical level. For this, the NetFPGA is used since it allows modifying the behavior as a network card by adding modules according to the needs of the project. In the design of the marking scheme for the arrival times of the test packets, the Traceband tool is used, this is in charge of sending and calculating the ABW and the NetFPGA is in charge of making the arrival timestamp of the packets in & nbsp; reception in hardware and based on this value the ABW estimation is made. The Timestamp and Identification modules were designed in the NetFPGA, and the changes required in Traceband to communicate with the NetFPGA

Esquema de timestamp en la recepción de paquetes de prueba a través de la Netfpga para la estimación de ancho de banda disponible en Traceband

Los servicios y aplicaciones que se ofrecen actualmente sobre internet como video bajo demanda, requieren estimación de parámetros que determinen la calidad de una conexión como el ancho de banda disponible. Para la estimación del ancho de banda disponible (ABW) se han desarrollado herramientas de software como Pathload, Spruce y Traceband. Estas herramientas presentan limitaciones en la precisión de la estimación debido a los retardos que sufren los paquetes en los procesos inherentes del sistema operativo. La herramienta requiere precisión en la captura del tiempo de llegada de los paquetes y esto se logra realizando el timestamp a nivel físico. Para ello se utiliza la NetFPGA dado que permite modificar el comportamiento como tarjeta de red adicionando módulos de acuerdo a las necesidades del proyecto. En el diseño del esquema de marcación de los tiempos de llegada de los paquetes de prueba se utiliza la herramienta Traceband, esta se encarga del envío y cálculo del ABW y la NetFPGA se encarga de realizar la marca de tiempo de llegada de los paquetes en la recepción en hardware y basados en este valor se realiza la estimación del ABW. Se diseñaron los módulos Timestamp e Identificación en la NetFPGA, y los cambios requeridos en Traceband para comunicarse con la NetFPGA

PathAB: A New Method to Estimate End-to-End Available Bandwidth of Network Path

Estimating available bandwidth accurately is extremely important for many network related applications, especially the ones which need real-time traffic information. With the ever increasing use of Internet, several available bandwidth measurement techniques have been proposed. But most of them assume fluid traffic model, whereas studies show that current Internet traffic follows Poisson distribution. Moreover, very few can operate in stand-alone mode and have relatively high estimation errors. We propose a new method, PathAB, which combines the concepts of three existing algorithms, MoSeab, PoissonProb and PathChirp. It first obtains a rough estimation of available bandwidth using an exponential probing train, and later obtains the final estimate using several Poisson distributed probing trains. It can operate both in client-server and stand-alone modes. Unlike other stand-alone methods, PathAB sends very small echo packets back-to-back after the large probe packets to reduce the cross-traffic effect in returning path as well as the estimation error

Mobile Ad-Hoc Networks

Being infrastructure-less and without central administration control, wireless ad-hoc networking is playing a more and more important role in extending the coverage of traditional wireless infrastructure (cellular networks, wireless LAN, etc). This book includes state-of-the-art techniques and solutions for wireless ad-hoc networks. It focuses on the following topics in ad-hoc networks: quality-of-service and video communication, routing protocol and cross-layer design. A few interesting problems about security and delay-tolerant networks are also discussed. This book is targeted to provide network engineers and researchers with design guidelines for large scale wireless ad hoc networks