Date of Original Version



Technical Report

Rights Management

All Rights Reserved

Abstract or Description

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."