Active/passive combination-type performance measurement method using change-of-measure framework

We propose a new method of performance measurement called the Change-of-Measure Based Passive/Active Monitoring (CoMPACT Monitor), in which estimates of the actual performance seen by users are obtained based on both active and passive measurement data. With this method, the performance experienced by an individual user, organization or application can be estimated from the results of scalable and lightweight measurements. The basic idea of our method is to weight the measurement value of an active-probe packet according to the number of user packets arriving near the active-probe packet. The number of user packets is measured passively. We give a mathematical background that supports the concept of the change-of-measure framework and propose an implementation of the method. Through simulation, we verify that the user performance can be estimated with a high degree of accuracy when the measurement interval is shorter than the mean burst duration. We also examine the accuracy of the method with respect to both the measurement interval and the number of probe packets and show that the accuracy itself can be roughly estimated by using the measured values. q 2004 Elsevier B.V. All rights reserved.