Evaluating the Benefits: Quantifying the Effects of TCP Options, QUIC, and CDNs on Throughput

To keep up with increasing demands on quality of experience, assessing and understanding the performance of network connections is crucial for web service providers. While different measures, like TCP options, alternative transport layer protocols like QUIC, or the hosting of services in CDNs, are expected to improve connection performance, no studies are quantifying such impacts on connections on the Internet. This paper introduces an active Internet measurement approach to assess the impacts of mentioned measures on connection performance. We conduct downloads from public web servers considering different vantage points, extract performance indicators like throughput, RTT, and retransmission rate, and survey speed-ups due to TCP option usage. Further, we compare the performance of QUIC-based downloads to TCP-based downloads considering different option configurations. Next to significant throughput improvements due to TCP option usage, in particular TCP window scaling, and QUIC, our study shows significantly increased performance for connections to domains hosted by different giant CDNs.Comment: Presented at the ACM/IRTF Applied Networking Research Workshop 2023 (ANRW23

Measuring ECN++: good news for ++, bad news for ECN over mobile

After ECN was first added to IP in 2001, it was hit by a succession of deployment problems. Studies in recent years have concluded that path traversal of ECN has become close to universal. In this article, we test whether the performance enhancement called ECN++ will face a similar deployment struggle as did base ECN. For this, we assess the feasibility of ECN++ deployment over mobile as well as fixed networks. In the process, we discover bad news for the base ECN protocol: contrary to accepted beliefs, more than half the mobile carriers we tested wipe the ECN field at the first upstream hop. All packets still get through, and congestion control still functions, just without the benefits of ECN. This throws into question whether previous studies used representative vantage points. This article also reports the good news that, wherever ECN gets through, we found no deployment problems for the "++" enhancement to ECN. The article includes the results of other in-depth tests that check whether servers that claim to support ECN actually respond correctly to explicit congestion feedback. Those interested can access the raw measurement data online.The work of Anna Maria Mandalari has been funded by the EU FP7 METRICS (607728) project. The work of Marcelo Bagnulo has been performed in the framework of the H2020-ICT-2014-2 project 5G NORMA and the 5G-City project funded by MINECO. This work was partially supported by the EU H2020 research and innovation program under grant agreement No. 644399 (MONROE) and grant agreement No. 688421 (MAMI)

Towards Scalable Network Traffic Measurement With Sketches

Driven by the ever-increasing data volume through the Internet, the per-port speed of network devices reached 400 Gbps, and high-end switches are capable of processing 25.6 Tbps of network traffic. To improve the efficiency and security of the network, network traffic measurement becomes more important than ever. For fast and accurate traffic measurement, managing an accurate working set of active flows (WSAF) at line rates is a key challenge. WSAF is usually located in high-speed but expensive memories, such as TCAM or SRAM, and thus their capacity is quite limited. To scale up the per-flow measurement, we pursue three thrusts. In the first thrust, we propose to use In-DRAM WSAF and put a compact data structure (i.e., sketch) called FlowRegulator before WSAF to compensate for DRAM\u27s slow access time. Per our results, FlowRegulator can substantially reduce massive influxes to WSAF without compromising measurement accuracy. In the second thrust, we integrate our sketch into a network system and propose an SDN-based WLAN monitoring and management framework called RFlow+, which can overcome the limitations of existing traffic measurement solutions (e.g., OpenFlow and sFlow), such as a limited view, incomplete flow statistics, and poor trade-off between measurement accuracy and CPU/network overheads. In the third thrust, we introduce a novel sampling scheme to deal with the poor trade-off that is provided by the standard simple random sampling (SRS). Even though SRS has been widely used in practice because of its simplicity, it provides non-uniform sampling rates for different flows, because it samples packets over an aggregated data flow. Starting with a simple idea that independent per-flow packet sampling provides the most accurate estimation of each flow, we introduce a new concept of per-flow systematic sampling, aiming to provide the same sampling rate across all flows. In addition, we provide a concrete sampling method called SketchFlow, which approximates the idea of the per-flow systematic sampling using a sketch saturation event

Propuesta metodológica para la identificación de patrones de falla de capa enlace de datos del modelo OSI y recuperación proactiva de equipos de comunicación aplicando algoritmos de aprendizaje automático

En este trabajo de investigación se ha propuesto una metodología que ayude a un administrador de red a poder predecir de manera rápida un fallo en la red. Se tomó una modelo de minería de datos como base para poder implementar la metodología, esta metodología abarca desde poder identificar los problemas que se vienen presentando habitualmente en la red hasta la solución definitiva de los mismos, por lo tanto, se tuvo que extraer datos de equipos de infraestructura de red mediante el protocolo simple de administración de red de una manera automatizada aplicando un script desarrollado en el lenguaje de programación Python. A los datos extraídos se les aplicaron diferentes técnicas de aprendizaje automático supervisado determinando de esta manera que la máquina de soporte vectorial es la más adecuada para poder predecir fallas en base a los datos analizados dado que se obtuvo un 97.8 % de probabilidad de predicción. Para poder realizar todas las pruebas necesarias sin afectar el estado de la red se propuso el utilizar un emulador grafico de red conocido como GNS3, es aquí donde se emuló una topología compuesta por equipos de comunicación de capa enlace de datos que pueda presentar fallas. Además, se propusieron políticas de configuración con la finalidad de que al aplicar un mecanismo automatizado para solucionar las fallas este no cometa errores y genere problemas al desactivar algunas características de equipos de red que pueda desencadenas más fallas. Para finalizar se propusieron 3 maneras de cómo aplicar una solución frente a la identificación de una posible falla a ocurrir señalando a un administrador de red y un software como los principales actores que intervendrían.Tesi

Passive and Active Measurement14th International Conference, PAM 2013, Hong Kong, China, March 18-19, 2013. Proceedings /

XII, 282 p. 135 illus.online resource