Hemera:WG:Metrology

Network metrology and traffic characterization (Metrology)

Leaders: Paulo Gonçalves (RESO), Konstantin Avrachenkov (MAESTRO)

Metrology (i.e. the deployment of a series of tools allowing the collecting of relevant information regarding the system’s status) of wide-area computer networks , is a recently- introduced discipline in the context of networks, that undergoes constant developments. In a nutshell, this activity consists in measuring along time, the nature and the amount of exchanged information between the constituents of a system. It is then a matter of using the collected data to forecast the network load’s evolution, so as to anticipate congestion, and more widely, to guarantee a certain Quality of Service, optimizing resources usage and protocols design.

From a statistical signal-processing viewpoint, collected traces correspond to (mul- tivariate) time series principally characterized by non-properties: non-gaussianity, non- stationarity, non-linearities, absence of a characteristic time scale (scale invariance). The research activity undertakes the development of reliable signal-analysis tools aimed at identifying these (non-)properties in the specific context of computer network traffic. In the course, we intend to clarify the importance of granularity of measurements.

This working group focuses on the two following questions:

• How does the traffic’s statistical properties really impact Quality of Service (QoS)?
• How to identify and to classify, in real time, transiting flows, according to a sensible typology?

Grid’5000 is a remarkable experimental facility to support investigation of this nature. Because it offers a fully controllable and reproducible environment, Grid’5000 allows to isolate (and to prescribe whenever it is possible) pertinent parameters of the network and to characterize their impact on the studied system. Several tools have been developed such as a packet capture plate-forme (MetroFlux) that permits, among other functional- ities, to reliably monitor a 10 Gbps link. Associated to this hardware device, there is a “Metrology service” as part of the networking toolbox offered to Grid’5000 users, for their own experimental needs. Presently, there only is one operational equipment of this type installed on the Lyon site of Grid’5000. We believe that a synchronized multiple-point measurement facility is the sensible next step towards a fine-grain metrology network overlaying Grid’5000.

Various teams – RESO (INRIA Lyon), MOAIS (Inria Grenoble), the Gipsa Lab (Grenoble), the University of Osaka (Japan) – are deploying on Grid’5000 a peta scale, high speed and long distance biomedical application. The main goal of this project is to evaluate the feasibility and to assess the performance of remote computing and visu- alization tasks. To this end, Osaka University has been connected to Grid’5000 trough a dedicated 10 Gbps link, and we foresee to instrument the Osaka site with a second MetroFlux probe for end-to-end performance estimation.