PeriScope: An Active Internet Probing and Measurement API
Khaled Harfoush, Azer Bestavros, John W. Byers · 2002
Abstract|Growing interest in inference and pre-diction of network characteristics is justied by its importance for a variety of network-aware appli-cations. One widely adopted strategy to charac-terize network conditions relies on active, end-to-end probing of the network. Active end-to-end probing techniques dier in (1) the structural composition of the probes they use (e.g., number and size of packets, the destination of various packets, the pro-tocols used, etc.), (2) the entity making the mea-surements (e.g. sender vs. receiver), and (3) the techniques used to combine measurements in or-der to infer specic metrics of interest. In this paper, we present Periscope: a Linux API that enables the denition of new probing structures and inference techniques from user space through a exible interface. PeriScope requires no sup-port from clients beyond the ability to respond to ICMP ECHO REQUESTs and is designed to minimize user/kernel crossings and to ensure various con-straints (e.g., back-to-back packet transmissions, ne-grained timing measurements) We show how to use Periscope for two dierent probing purposes, namely the measurement of shared packet losses between pairs of endpoints and for the measure-ment of subpath bandwidth. Results from Internet experiments for both of these goals are also pre-sented. I.