Emodis : an end-based network monitoring and diagnosis system

Abstract

Network monitoring and diagnosis capabilities are critical for the seamless operation of a network. ISPs use sophisticated systems to routinely monitor and diagnose their networks, but end users do not have such capabilities. To address this problem, we develop Emodis—a network monitoring and diagnosis system. In this paper, we describe the architecture and the software components of Emodis. Like other end-user oriented network monitoring systems, Emodis is deployed on a diverse set of Internet nodes, so it shares common requirements such as security and robustness with these systems. However, the focus of Emodis is on route-sensitive path metrics such as available bandwidth and packet loss rate, resulting in two unique characteristics: (1) it implements a variety of measurement techniques, including sophisticated bandwidth measurement techniques, but hides many technical details from end users; (2) it implements a scheduling algorithm to synchronize the measurements from different vantage points, which relieves end users from complicated network measurement management. Ningning Hu and Peter Steenkiste were in part supported by the NSF under award number CCR-0205266.